doi:10.1507/endocrj.EJ23-0671

Original

Impact of coronavirus disease 2019 on medical practicein endocrine and metabolic diseases in Japan: anationwide surveillance study conducted by the Japan
Endocrine Society
Katsunori Manaka1)†, Sayaka Kato2), 3)†, Ryuichi Sakamoto4)†, Hajime Yamakage2), Tsugumi Uema5),
Shiori Kawai6), Megumi Shibata7), Izumi Hiratsuka7), Sawako Nakachi5), Takeshi Onoue8),
Takefumi Tsuchiya6), Michiaki Fukui3), Koshi Hashimoto6), Atsushi Suzuki7), Noriko Makita1),
Yoshihiro Ogawa4), Hiroshi Arima8), Noriko Satoh-Asahara2), 9) and Hiroaki Masuzaki5)
1)

Department of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo 113-8655, Japan
Department of Endocrinology, Metabolism and Hypertension Research, Clinical Research Institute, National Hospital
Organization, Kyoto Medical Center, Kyoto 612-8555, Japan3)
Department of Endocrinology and Metabolism, Graduate School of Medical Science, Kyoto Prefectural University of Medicine,
Kyoto 602-8566, Japan
4)
Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582,
Japan
5)
Second Department of Internal Medicine (Endocrinology, Diabetes and Metabolism, Hematology, Rheumatology), Graduate Schoolof Medicine, University of the Ryukyus, Okinawa 903-0213, Japan
6)
Department of Diabetes, Endocrinology and Hematology, Dokkyo Medical University Saitama Medical Center, Saitama 343-8555,
Japan
7)
Department of Endocrinology, Diabetes and Metabolism, Fujita Health University, School of Medicine, Aichi 470-1192, Japan
8)
Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Aichi 466-8550, Japan
9)
Department of Metabolic Syndrome and Nutritional Science, Research Institute of Environmental Medicine, Nagoya University,
Aichi 466-8550, Japan
2)

Abstract. We investigated the impact of the Coronavirus disease 2019 (COVID-19) pandemic on the management of
endocrine and metabolic disorders in Japan. We conducted a cross-sectional nationwide questionnaire survey targeting boardcertified endocrinologists under the auspices of the Japan Endocrine Society. The questionnaire consisted of multiple-choicequestions and open-ended responses. Out of approximately 2,700 specialists, 528 (19.5%) opted to participate, suggesting ahigh level of interest in COVID-19 management among endocrinologists. The study found that almost half of participants had
encountered cases of endocrine and metabolic disorders following COVID-19 infection or vaccination. Conditions related tothyroid diseases, glucose metabolism disorders/diabetes, and hypothalamic-pituitary disorders were particularly prevalent.
Diabetes and obesity were identified as having high rates of severe cases or fatalities due to COVID-19. The study also
highlighted challenges in routine diagnosis and treatment, emphasizing the potential benefits of combining remoteconsultations with in-person visits to optimize the frequency of examinations and check-ups during infectious disease
outbreak which disrupts access to healthcare providers. The insights obtained from this survey are expected to contribute toensuring appropriate healthcare provision for patients with endocrine and metabolic disorders by using flexible consultation
formats, particularly even in the conditions where medical access may be limited due to future outbreaks of emerging or reemerging infectious diseases.
Key words: Coronavirus disease 2019 (COVID-19), Pandemic, Post COVID-19 condition (long COVID), Endocrine andmetabolic diseases

Submitted Dec. 12, 2023; Accepted Feb. 7, 2024 as EJ23-0671
Released online in J-STAGE as advance publication Mar. 9, 2024

Correspondence to: Hiroaki Masuzaki, Second Department ofInternal Medicine (Endocrinology, Diabetes and Metabolism,
Hematology, Rheumatology), Graduate School of Medicine,
University of the Ryukyus, 207 Uehara, Nishihara, Okinawa
903-0213, Japan.
E-mail: hiroaki@med.u-ryukyu.ac.jp
Correspondence to: Noriko Satoh-Asahara, Department ofEndocrinology, Metabolism and Hypertension Research, Clinical©The Japan Endocrine Society

Research Institute, National Hospital Organization, Kyoto Medical
Center, 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto
612-8555, Japan.
E-mail: nsatoh@kuhp.kyoto-u.ac.jp
Correspondence to: Hiroshi Arima, Department of Endocrinology
and Diabetes, Nagoya University Graduate School of Medicine,
Nagoya 466-8550, Japan.
E-mail: arima105@med.nagoya-u.ac.jp†
These authors contributed equally to this study.

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Manaka et al.

THE OUTBREAK of the coronavirus disease 2019
(COVID-19) has had a profound impact on the medical
and healthcare fields. In the management of various
endocrine and metabolic diseases, it has become impor‐tant to address not only acute problems associated with
COVID-19 but also medium to long-term problems
related to the difficulties in the management of underly‐
ing diseases, complications, and a decline in quality oflife in a broad sense. Given this background, the present
study aims to elucidate the actual impact of COVID-19
on the diagnosis and treatment of endocrine andmetabolic diseases in Japan. To achieve this goal, anationwide survey targeting board-certified endocrinolo‐
gist was conducted by the Japan Endocrine Society. We
attempted to clarify the current situation and challenges
in the clinical care of endocrinology and metabolism.
There have been numerous studies on the impact of
COVID-19, including its effects on the whole healthcare
system [1-5], mental health care [6], medical education[7], cancer [8, 9], thyroid surgery [10-14], diabetes melli‐tus [15], and more. However, there has been no prece‐dent for a large-scale nationwide survey targeting
specialists in endocrinology and metabolism, with afocus on the impact of COVID-19 on endocrine andmetabolic disease management. The analysis of theissues related to the impact of COVID-19 on endocrine
and metabolic disease management has the potential toprovide significant insights for establishing a rationaland scientifically-informed response to future pandemics
of emerging or re-emerging infectious diseases, thus con‐tributing to the development of a more robust healthcare
system. In addition, it is possible that underlying unre‐solved problems in the routine clinical care of endocrine
and metabolic diseases will become clear from this kindof study, which could lead to improvements in the qual‐
ity of healthcare.

Materials and Methods
Study design and participantsThis study was a cross-sectional questionnaire survey
whose primary purpose was to investigate the actual sta‐tus during the period, for which a full survey was
employed. The target population was approximately
2,700 specialists in endocrinology and metabolism(internal medicine) certified by the Japan Endocrine
Society. No special exclusion criteria were set for thissurvey. From the secretariat of the Japan Endocrine
Society, a request for responses to the questionnaire wassent via email to the target population on February 10,2023. Simultaneously, the request was also posted on theJapan Endocrine Society’s website. Two additional
reminders requesting responses to the questionnaire weresent via email. The response period was from February
10, 2023 to March 3, 2023 (22 days).

Questionnaire
The structure of the questionnaire is as follows: 1)
Basic information on the participants was obtained,
including Japan Endocrine Society membership number,
years of working as a physician, name of the institution
they belonged to, whether they were responsible for theendocrinology department at their institution, and thesize of the institution (number of beds and approximate
number of patients in the relevant department). Since
Japan Endocrine Society membership numbers were pro‐vided, duplicate responses could be avoided. 2) Subjects
were asked about the effects of COVID-19 pandemic on
the practice of endocrinology and metabolism by dis‐eases and the reasons for these effects. They answered
the questionnaire according to seven classifications ofdiseases: (1) general practice of endocrine and metabolic
diseases and post-acute sequelae of COVID-19 infection(long COVID); (2) hypothalamic-pituitary disorders; (3)thyroid diseases; (4) parathyroid diseases and osteoporo‐sis; (5) adrenal diseases and hypertension; (6) diabetes
and obesity; and (7) dyslipidemia and hyperuricemia.
The questions were multiple-choice, except for somenumerical response questions (years of working as aphysician), and the “other” option was left open for par‐ticipants to provide further details.
The questionnaire was developed in consultation with18 members, including 15 physicians and a statistician,led by the directors of the Japan Endocrine Society. Sub‐sequently, 2–3 endocrinologists from each of the 7 facili‐ties participating in this survey evaluated the draft for
readability of the questionnaire, identity of interpretation,and ease of response, and adjustments were madeaccordingly.
The questionnaire form was created in Google Forms
and information on this survey was posted on the Japan
Endocrine Society website as well as emailed to the sub‐jects. The information on this survey was also posted.
The questionnaire contained 109 questions, and the esti‐
mated average response time was 20 minutes. The ques‐tionnaire is shown in the Supplementary Fig. 1 (English
version) and Supplementary Fig. 2 (Japanese version).
EthicsThis survey was conducted in compliance with the
Declaration of Helsinki (revised October 2013) and the
Ethical Guidelines for Life Sciences and Medical
Research Involving Human Subjects (Ministry of
Education, Culture, Sports, Science and Technology,
Ministry of Health, Labour and Welfare, and Ministry of
Economy, Trade and Industry Notification No. 1, 2021).

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COVID-19 and endocrine care in JapanThe ethical review of this survey was approved by The
Ethics Committee of University of the Ryukyus for
Medical and Health Research Involving Human
Subjects, which is the main research institution, througha central collective review, and was conducted with thepermission of the heads of all research institutions(University of the Ryukyus permission number: No. 2066).

Statistical analysis
All returned responses were considered valid
responses, except for duplicate responses, which were
judged by Japan Endocrine Society membership number.
Summary statistics (mean, standard deviation, median,interquartile range, and range) were calculated fornumerical responses, and frequency tabulations (numberof response choices and percentage) was conducted for
multiple-choice responses. We were unable to obtain
direct information on the characteristics of nonrespondents, so we decided to estimate the target
population through sampling. To estimate the character‐istics of target population through sampling from 2,700
individuals, ensuring a margin of error of 5% and a con‐fidence level of 95%, a minimum of 337 surveys would
be required. Therefore, we randomly sampled 360 indi‐viduals and conducted confirmation of the facilities ofthese 360 individuals, as well as verification of the infor‐
mation about their facilities. The denominator for per‐centage calculation was the number of valid responses tothe question. Among free-text responses, word responses(e.g., free-text responses to the “other”) were frequencytabulated by reading and coding by two medical special‐ists. For questions with more than 50 short answers,
word frequency tally, co-occurrence analysis, and corre‐
spondence analysis were conducted by text mining. For
similar questions across domains, frequency tabulations
were conducted after recoding to ensure commonality
across domains. Text mining was performed on Japanese
sentences. We made a word list of nouns, verbs andadjectives from the headlines using the Japanese lan‐
guage morphological analysis program ChaSen version
2.1 (Nara Institute of Science and Technology). The cooccurrence network analysis was performed on theextracted data. In the co-occurrence network chart,words with similar appearance patterns (i.e., with highdegrees of co-occurrence) are connected by edges.
Thicker edges correspond to stronger co-occurrence. If
words are not connected with edges, there is no strong
co-occurrence. The color of each node represents subgraphs, which means that the same color belongs to thesame group. Edges between words belonging to different
sub-graphs are represented by dotted lines. By consider‐ing words with strong co-occurrences and sub-graphs,
the meaning of a particular word in the text can beinterpreted.
All statistical analyses were conducted using SPSS
version 24.0 for Windows and SPSS Text Analytics(IBM Japan, Ltd.).

Results
We investigated the impact of the COVID-19 pan‐demic on the management of endocrine and metabolic
disorders in Japan, performing a nationwide crosssectional questionnaire survey targeting endocrinologists
who were board-certified by the Japan Endocrine Society.
We received responses from 528 out of approximately
2,700 endocrinologists, resulting in a 20% response rate.
Not a small number of responses suggests a significant
COVID-19 impact on the management of endocrine andmetabolic diseases, along with a high level of interest
among endocrinologists.
The median years of experience as physicians among
the responding specialists were 22 years. In terms of thetypes of healthcare facilities where the participants
worked, the response rate from participants working inclinics was lower, while the response rate from partici‐
pants working in university hospitals and general hospi‐
tals was higher; 42% were affiliated with university
hospitals, 42% with general city hospitals, and 15% withclinics. The fact that most of the respondents were physi‐
cians working in university hospitals or general city hos‐pitals indicates their involvement in highly specialized
endocrine and metabolism practice (Table 1).
Among the participants, 179 (34%) had experiencediagnosing endocrine abnormalities in patients follow‐
ing COVID-19 vaccine administration (Table 2). The
breakdown of endocrine abnormalities following
COVID-19 vaccination was as follows: 137 participants(77%) had experienced abnormal findings in thyroid, 43(24%) had abnormal findings in glucose metabolism, and34 (19%) had abnormal findings in the hypothalamicpituitary axis.
Additionally, 157 out of the 528 participants (30%)
had experience diagnosing endocrine abnormalities inpatients following COVID-19 infection. The breakdown
of endocrine abnormalities in this group following
COVID-19 was as follows: 83 participants (53%) had
experienced abnormal findings in thyroid, 63 (40%) had
abnormal findings in glucose metabolism, and 36 (23%)
had abnormal findings in the hypothalamic-pituitaryaxis.
Almost half of the participants (249 out of 528; 47%)
had experience diagnosing endocrine abnormalities inpatients following COVID-19 vaccine administration
and/or COVID-19 infection.
Furthermore, 253 participants (48%) had experience inEndocrine Journal Advance Publication

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Manaka et al.

Table 1

Characteristics of survey respondents and target populations
Respondents (n = 528)

Target population

Years of experience as a physician (year)
Mean ± SD

23.6 ± 10.3

N/A

22.0 [15.0–31.0]; (3–53)

N/A

257, 48.7%

N/A

Clinic77, 14.6%

30.8%

City hospital

223, 42.2%

34.4%

University hospital

224, 42.4%

31.1%

4, 0.8%3.6%456, 86.4%

66.1%

More than 500 beds (n, % [of n = 456])

309, 67.8%

61.3%

400–499 beds

36, 7.9%

8.4%

300–399 beds

36, 7.9%

8.8%

200–299 beds

36, 7.9%

5.9%

100–199 beds

19, 4.2%

9.7%

20–99 beds

17, 3.7%

5.0%

1–19 beds

3, 0.7%0.8%

11, 2.1%

2.5%

Median [IQR] (range)
Responsible for the endocrine and metabolic diseasedepartment (n, %)Type of institution (n, %)Other (government, business, etc.)
Bedded facility (n, %)Area (n, %)Hokkaido Region
Tohoku Region20, 3.8%

4.0%

Kanto Region98, 18.6%

35.9%

Chubu Region

146, 27.7%

19.7%

Kinki Region

104, 19.7%

20.6%

Chugoku Region20, 3.8%

4.5%

Shikoku Region15, 2.8%

2.9%

Kyushu/Okinawa Region84, 15.9%

9.9%

Unknown

30, 5.7%0%

SD: standard deviation, IQR: inter-quartile range [25%, 75%], N/A: not available
The facilities of the target population: From the publicly available directory provided by the Japan
Endocrine Society, 360 individuals were randomly sampled and identified the facilities using searchengines.
The areas of the target population: The areas were extracted directly from the publicly available
directory provided by the Japan Endocrine Society.
Areas in Japan: Japan was divided into eight regions (https://www.japan-guide.com/list/e1001.html).

treating “long COVID.” The common symptoms inpatients with long COVID which the participants had
experienced were fatigue and malaise (88%), chronic
cough (68%), taste disorder (42%), shortness of breath(34%), olfactory disorders (32%), and deficits in atten‐
tion (27%). These symptoms may also be attributable toendocrine and metabolic disorders, such as thyroid dys‐function, adrenal insufficiency, and pituitary insuffi‐
ciency. Therefore, patients are sometimes referred to an
endocrinologist for specialized care and evaluation.
As many as 488 participants (92%) answered a binary
question affirming that the rapid spread of COVID-19
after April 2020 had impact on changes in the clinicalenvironment and the number of hospitalized patientswith endocrine and metabolic disorders (Table 3). The
breakdown of the changes showed that 391 participants(81%) started conducting telephone telemedicine, 318(65%) made changes to the clinical environment such as
waiting rooms and examination rooms, and 274 (56%)
reduced the number of hospitalized patients. The initia‐
tion of video telemedicine remained at low rate (7.4%).

Hypothalamic-pituitary disorders
There were 223 participants (42%) who responded
that COVID-19 pandemic had negative effects on the
management of hypothalamic-pituitary disorders

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COVID-19 and endocrine care in Japan

Table 2Abnormal endocrinological findings and sequelae related to the COVID-19 experienced
Total (n = 528)

Experience of Endo-Abnorm after vaccine: yes (n, %)179, 33.9%

Region in which abnormal findings were found (n, % [of n = 179])*
Hypothalamic and Pituitary gland

34, 19.1%

Thyroid gland

137, 77.0%

Parathyroid gland2, 1.1%

Adrenal gland

13, 7.3%

Pancreas and gastrointestinal tract

5, 2.8%

Gonads3, 1.7%

Glucose metabolism

43, 24.2%

Other

4, 2.2%

Experience of Endo-Abnorm after COVID-19 infection: yes (n, %)157, 29.7%

Region in which abnormal findings were found (n, % [of n = 157])*
Hypothalamic and Pituitary gland36, 22.9%

Thyroid gland

83, 52.9%

Parathyroid gland2, 1.3%

Adrenal gland

14, 8.9%

Pancreas and gastrointestinal tract

3, 1.9%Gonads7, 4.5%

Glucose metabolism

63, 40.1%

Other

3, 1.9%Experience of sequelae after COVID-19 infection: yes (n, %)253, 47.9%

Experienced symptoms (n, % [of n = 253])
Fatigue and malaise

224, 88.2%

Arthralgia

23, 9.1%

Myalgia

25, 9.8%

Cough172, 67.7%

Sputum55, 21.7%

Shortness of breath85, 33.5%

Chest pain

18, 7.1%

Alopecia

37, 14.6%

Memory impairment

25, 9.8%

Concentration problems

68, 26.8%

Headache45, 17.7%

Depression

47, 18.5%

Olfactory disturbances

80, 31.5%

Taste disorder

108, 42.5%

Palpitations

19, 7.5%

Diarrhea

9, 3.5%

Abdominal pain

7, 2.8%Sleep disturbance29, 11.4%

Muscle weakness

26, 10.2%

Other

7, 2.8%Endo-Abnorm: endocrinological abnormalities*: multiple-answer question(Fig. 1). The breakdown of the negative effects on
hypothalamic-pituitary disorders due to COVID-19 was
as follows: experiencing cases requiring steroid coverage(43%), encountering cases where hospitalization was
delayed or not possible (37%), and experiencing
cases where necessary consultations and tests became

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Manaka et al.

Table 3

Changes in medical practice patterns
Total (n = 528)

Changes in medical practice patterns after COVID-19 (n, %)Yes488, 92.4%

No40, 7.6%

Details of changes in the form of medical treatment (n, % [of n = 488])
Telephone telemedicine

Fig. 1391, 80.5%

Video telemedicine

36, 7.4%

Changed the hospital environment

318, 65.4%

Number of inpatients admitted to the hospital decreased.

274, 56.4%

Other (free comment)

22, 4.5%

The impact of COVID-19 pandemic on each endocrine disease area
The frequency of responses to the question, “How has COVID-19 pandemic affected your practice?" in each disease area:
bar graph
Answers are chosen exclusively from the following four:1) It had negative effects [Negative (only)]2) There were both positive and negative effects [Negative and Positive]3) It had positive effects [Positive (only)]4) There was no effect [No effect].

insufficient due to extended visitation periods (35%)
were ranked as the most prevalent (Table 4).
A decrease in the number of surgical cases of pituitary
tumor was reported by 69 participants (13%), with themost common reason being restrictions in the operationof the operating room (65%).
In the management of patients with arginine vaso‐pressin (AVP) deficiency (central diabetes insipidus), 24
participants (5%) reported that they had experienced dif‐ficulties in managing electrolytes. The main reasons

included changes in the required dosage of desmopressin(29%), the occurrence of hyponatremia due to intra‐
venous fluids administered for the treatment of
COVID-19 (29%), and the inability to undergo necessary
consultations and blood tests due to isolation (29%).
Furthermore, 82 participants (16%) faced challenges
with steroid coverage. The primary reasons were fluctua‐
tions in the required steroid dosage (54%) and the onsetof adrenal crisis (52%).
Twenty-nine participants reported experiencing

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COVID-19 and endocrine care in Japan

Table 4

Reasons for negative effect of COVID-19 on practice, by disease

Classification of diseases

Rank 1

Rank 2

There were patients who were not
There were some patients in whomable to be hospitalized or whose
Hypothalamic and Pituitary gland Reason steroid coverage was required during admission was delayed due to
COVID-19 infection
COVID-19 pandemic, even though(negative effect: n = 220)
they needed hospitalizationn, %Graves’ disease(negative effect: n = 184)

ReasonHashimoto’s disease(negative effect: n = 82)

ReasonSubacute thyroiditis(negative effect: n = 93)

n, %

n, %

Thyroid tumor (malignant)(negative effect: n = 115)

Reasonn, %Hypertension(negative effect: n = 234)

Obesity(negative effect: n = 378)n, %Because it interfered with thefollow-up observation
87, 68.0%

63, 54.8%

44, 61.1%

58, 51.8%

133, 56.8%

n, %Reason401, 88.7%

78, 35.5%

Because it interfered with thedetection and diagnosis of the disease

Because it interfered with oral
radioiodine therapy

67, 36.4%

32, 17.4%

Because it interfered with thedetection and diagnosis of the disease

Because it interfered with theinitiation of drug therapy

24, 29.3%

7, 8.5%

Because it interfered with thecontinuation of drug therapy
14, 15.1%
Because it interfered with thecontinuation of drug therapy

Because the risk of dyslipidemia
increased due to obesity, drinking
Reasonalcohol, lack of exercise, etc., as aresult of home-based living
233, 84.4%

Because the risk of hyperuricemia
increased due to obesity, drinking
Reasonalcohol, overeating, etc., as a resultof home-based livingn, %118, 75.2%

Because it interfered with theinitiation of drug therapy
6, 6.5%
Because it interfered with theinitiation of drug therapy

9, 20.9%

5, 11.6%

Because it interfered with thedetection and diagnosis of the disease

Because it interfered with thesurgical therapy

49, 38.3%

23, 18.0%

Because it interfered with the surgical Because it interfered with thetherapyfollow-up observation
53, 46.1%
Because it interfered with surgicaltherapy

45, 39.1%
Because it interfered with thecontinuation of drug therapy

22, 30.6%

16, 22.2%

Because it interfered with thedetection and diagnosis of the disease

Because it interfered with theinitiation of drug therapy

57, 50.9%

23, 20.5%

Because many patients were late inreceiving medical examinations,diagnoses, and starting treatment

Because many patients had
problems with weight loss
Because many patients failed tovisit the hospital

129, 55.1%

278, 61.5%

Because many patients had difficulty Because many patients had difficultywith exercise therapy
with diet therapy
360, 95.2%

Insufficient monitoring throughmedical examinations due toprolonged intervals between
visits82, 37.3%

Because many patients had difficulty Because many patients had difficulty
Reasonwith exercise therapy
with diet therapyn, %Hyperuricemia(negative effect: n = 157)

33, 76.7%

Because many patients delayed
Reason seeing a doctor, getting diagnosed,or starting treatmentn, %Dyslipidemia(negative effect: n = 276)

69, 74.2%

Because it interfered with theReasoncontinuation of drug therapyn, %Diabetes mellitus(negative effect: n = 452)

64, 78.0%

Because it interfered with theReason detection and diagnosis of thediseasen, %Osteoporosis(negative effect: n = 112)

Because it interfered with thecontinuation of drug therapy

Because it interfered with theReason detection and diagnosis of thediseasen, %Parathyroid disease(negative effect: n = 72)

112, 60.9%

Because it interfered with theReason detection and diagnosis of thediseasen, %Thyroid tumor (benign)(negative effect: n = 128)

Because it interfered with thecontinuation of drug therapy

Because it interfered with theReason detection and diagnosis of thediseasen, %Painless thyroiditis(negative effect: n = 43)

94, 42.7%

Rank 398, 41.9%
Because many patients gained
weight266, 58.8%
Because many patients delayed
seeing a doctor, getting
diagnosed, and starting
treatment

277, 73.3%

147, 38.9%

Because the patients avoided going to
medical institutions and treatment
intervention was delayed, althoughabnormal values were indicated inhealth checkups

Because the patients stopped
seeing their doctors

159, 57.6%

105, 38.0%

Because the patients avoided going to
medical institutions and treatment
intervention was delayed, althoughabnormal values were indicated inhealth checkups

Because the patients stopped
seeing their doctors

86, 54.8%

69, 43.9%

The rank is determined by the frequency of selected reasons (multiple choices allowed) for the negative effect of COVID-19 on practice, as reported byrespondents who experienced such effect.

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Manaka et al.

hypothalamic-pituitary-adrenal (HPA) axis abnormalities
after vaccination, with more than half of the participants
clearly stating a secondary etiology: 17 secondary, 1 pri‐mary, and 11 unknown. Twenty-six participants experi‐
enced HPA axis abnormalities after COVID-19 infection,with the etiology of all 17 participants who explicitly
stated the etiology as being secondary.

Thyroid diseases
There were 187 participants (35%) who responded
that COVID-19 pandemic had negative effects on the
management of Graves’ diseases (Fig. 1). The break‐down of the negative effects on Graves’ disease due to
COVID-19 pandemic was as follows: experiencing cases
who had difficulties in continuing medication (61%) andexperiencing cases with delayed diagnosis (36%) wereranked as the most prevalent (Table 4).
In the management of Graves’ disease patients with
COVID-19 infection, 86 participants (16%) reported thatthey had experienced difficulties. The main reasons
included the inability to undergo necessary consultations
and examinations (55%), the inability to prescribe neces‐sary medications (37%), and a worsening of the condi‐tion due to the interruption of oral medication anddisruptions in lifestyle habits (37%).
Similarly, in the management of Hashimoto’s disease(hypothyroidism) patients with COVID-19 infection, 86
participants (16%) reported that they had experienced
difficulties. The main reasons included the difficulties incontinuing medications (78%) and the delay in diagnosisof the disease (29%).
In addition, there were some responses that
COVID-19 pandemic had negative effects on the man‐agement of subacute thyroiditis, painless thyroiditis,
benign thyroid tumors, and malignant thyroid tumors.
Parathyroid diseases and osteoporosis
There were 75 participants (14%) who responded that
COVID-19 pandemic had negative effects on the man‐agement of parathyroid diseases (Fig. 1).
The breakdown of the negative effects on parathyroid
diseases due to COVID-19 pandemic was as follows:
experiencing cases with delayed diagnosis (61%) andexperiencing cases who had obstacles in surgical treat‐ment (31%) were ranked as the most prevalent (Table 4).
A decrease in the number of surgical cases of parathy‐
roid disease was reported by 56 participants (11%), withthe most common reason being restrictions in the opera‐tion of the operating room (62%).
In the management of calcium and phosphorus
metabolism in patients contracting COVID-19 infection,
only 8 participants (2%) reported they had experienced
difficulties.

There were 116 participants (22%) who responded that
COVID-19 pandemic had negative effects on the man‐agement of osteoporosis (Fig. 1).
The breakdown of the negative effects on osteoporosis
due to COVID-19 pandemic was as follows: experienc‐
ing cases who had difficulties in continuing medication(58%) and experiencing cases with delayed diagnosis(57%) were ranked as the most prevalent.
In addition, there were as many as 285 participants(54%) who responded that COVID-19 pandemic had
negative effects on the management of musculoskeletal
health.

Adrenal diseases and hypertension
There were 235 participants (45%) who responded
that COVID-19 pandemic had an adverse effect on the
management of hypertension (Fig. 1).
The breakdown of the negative effects on hyperten‐sion due to COVID-19 pandemic was as follows: experi‐
encing cases who had obstacles in medical treatment(initiation, dose adjustment, and continuation) (57%) andexperiencing cases with delayed diagnosis (55%) wereranked as the most prevalent (Table 4).
Regarding the treatment of adrenal disorders, 118participants (22%) reported a decrease in the screening
frequency for primary aldosteronism. The most promi‐
nent reason was the decrease in patient visits, which
accounted for about 86%.
Similarly, there were 59 participants (11%) who
reported a decrease in treating adrenal tumors. The main
reasons included a decrease in opportunities for imaging
tests (50%) and a decrease in opportunities for detailed
examinations (38%).
A decrease in the number of surgical cases of adrenal
tumor was reported by 70 participants (13%), with themain reasons being restrictions on operating room usage(55%) and a decrease in patient visits (41%).
On the other hand, 82 participants (16%) reported anincrease in the frequency of treating adrenal insuffi‐
ciency due to COVID-19 pandemic. The main reason
cited was that COVID-19 itself was a cause of adrenal
insufficiency, mentioned by 55% of the participants in ahigh proportion.
Regarding sick day rules for adrenal insufficiency,
21% of the participants advised an increase in glucocorti‐
coid (GC) replacement dose for their patients withadrenal insufficiency if COVID-19 infection was identi‐
fied regardless of symptoms; 26% advised to increase thedose depending on symptoms; and more than half did notgive specific instructions for COVID-19 infection. And
in the case of COVID-19 vaccination, 5% of participants
advised to increase the dose even if there were no
adverse reactions, 68% advised to increase the dose if

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COVID-19 and endocrine care in Japan

there were adverse reactions, and 26% did not instruct toincrease the dose. Of the participants who indicated a GC
dose increase at the time of vaccination even in theabsence of an adverse reaction, more than half (14 partic‐
ipants) were participants who also advised an increaseat the time of COVID-19 identification in the absenceof symptoms.

Diabetes mellitus and obesity disease
There were as many as 455 participants (86%) who
responded that COVID-19 had negative effects on the
management of diabetes mellitus (Fig. 1).
The major negative effects on the management ofdiabetes mellitus due to COVID-19 pandemic were as
follows: experiencing cases who had obstacles to exer‐
cise therapy (89%), obstacles to dietary therapy (62%),weight gain (59%), and dealing with delays in patient
visits, diagnoses, and treatment initiation (57%)(Table 4).
The spread of the COVID-19 led to further effects:
extended patient appointment intervals (66%), introduc‐tion of telephone telemedicine (62%), reduction or can‐cellation of activities like foot care, diabetes classes, andpatient meetings (55%), as well as a decrease in hospital
admissions for treatment of diabetes mellitus (55%).
Many of the participants encountered diabetes mellitus
patients with moderate cases of COVID-19 infection that
required interventions like oxygen therapy or hospitaliza‐tion (56%), severe cases of COVID-19 infection necessi‐
tating intensive care unit admission or ventilator use(42%), and fatal cases (22%).
In the management of patients with diabetes mellitus,
265 participants (50%) reported experiencing challenges
in controlling blood glucose levels. The primary reasonsfor these challenges were as follows: corticosteroids
administered for COVID-19 pneumonia treatment(64%), inability to attend necessary examinations due toisolation (54%), and the onset of conditions like diabetic
ketoacidosis (DKA) or hyperosmolar hyperglycemic
state (HHS) (38%).
There were as many as 382 participants (72%) who
responded that COVID-19 pandemic had negative effects
on the management of obesity (Fig. 1).
The major negative effects on the management of obe‐
sity due to COVID-19 were as follows: experiencing
cases who had obstacles to exercise therapy (95%) andobstacles to dietary therapy (73%) (Table 4).
Similar to diabetes mellitus, many of the participants
encountered obese patients with moderate cases of
COVID-19 infection (37%), severe cases of COVID-19
infection (26%), and fatal cases (8%).

9Dyslipidemia and hyperuricemia
There were 275 participants (52%) who responded
that COVID-19 pandemic had negative effects on the
management of dyslipidemia (Fig. 1).
The major reasons for negative effects on the manage‐
ment of dyslipidemia due to COVID-19 pandemic wereas follows: a shift towards a predominantly home-based
lifestyle, leading to an increased risk of lipid abnormali‐ties (84%) and a reluctance to visit medical facilities,
resulting in delayed treatment interventions (58%)(Table 4).
In the management of dyslipidemia in patients with
COVID-19 infection, 67 participants (13%) reported
they had experienced difficulties.
The major reasons included the inability to attend nec‐
essary examinations due to isolation (75%) and theinability to prescribe necessary medications (65%).
There were 157 participants (30%) who responded
that COVID-19 had negative effects on the managementof hyperuricemia (Fig. 1).
The major reasons for negative effects on the manage‐
ment of hyperuricemia due to COVID-19 pandemic wereas follows: a shift towards a predominantly home-based
lifestyle, leading to an increased risk of hyperuricemia(75%), a reluctance to visit medical facilities, resulting indelayed treatment interventions (56%), and interruptionsof regular medical visits (45%) (Table 4).
In the management of hyperuricemia in patients with
COVID-19 infection, 31 endocrinologists (6%) reported
they had experienced difficulties.
The major reasons included the inability to attend nec‐
essary examinations due to isolation (83%) and theinability to prescribe necessary medications (64%).
Text mining
A text mining analysis was performed for the diabetes
area with more than 50 responses regarding the reasonsfor the positive effects of COVID-19 pandemic on medi‐
cal practice. Co-occurrence networks analysis is shownin Fig. 2, and a co-occurrence network diagram including
the notation of the language of analysis is shown in Sup‐
plementary Fig. 3. The largest response category was
extracted related to “Lifestyle improvement due todecrease in eating out and meeting at restaurants” (n =72, 13.6%). Next, responses related to “Lifestyle changes
associated with remote working” (n = 10, 1.9%) and“Improvement in understanding of the disease in relation
to infection prevention and control of long COVID” (n =8, 1.5%) were extracted as response groups with rela‐
tively broad keywords. Finally, a group of responses
related to “Expansion of video and telephone
telemedicine” was extracted as a characteristic responsegroup (n = 9, 1.7%).

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10

Fig. 2

Manaka et al.

Positive impact of COVID-19 pandemic on the diabetes mellitus and their relationships from open-ended questions. Results of
Text Mining for Open-ended Responses to the Question, “What positive effects have COVID-19 had on your practice?” in the
Diabetes Mellitus Domain: Co-occurrence network and frequency.

Discussion
This surveillance of Japan Endocrine Society-certified
endocrinologists revealed the significant impact of the
COVID-19 pandemic on endocrine and metabolic care in
Japan. However, in several disease areas, such as
Hashimoto’s thyroiditis and osteoporosis, many partici‐
pants reported no notable impact. It seems to be due toroutine care involving fewer tests and interventions.
Many practitioners adopted remote consultations, pri‐marily by telephone telemedicine, with a few incorpo‐
rating video telemedicine into their practices. The
effectiveness of remote consultations, established inWestern countries [16-18], is considered valuable for
ensuring access to medical care during outbreaks ofemerging or re-emerging infectious diseases [19]. In
Japan, in 2023, a report indicated that telemedicine
combined with face-to-face treatment for psychiatric dis‐orders (depression, anxiety, and obsessive-compulsive
disorder) was non-inferior to face-to-face treatment in
the Short Form Health Study Mental Component
Summary (SF-36 MCS) score. These findings support

the potential for widespread use of video telemedicine ina variety of medical conditions [20]. In Japan, it is desir‐able for telemedicine to become a regular option in nonoutbreak situations to ensure access to medical careduring future infectious disease outbreaks. In terms of
disease, one-third of the participants had experienceswith endocrine and metabolic disorders after COVID-19
infection or vaccination, especially abnormalities of thy‐roid, HPA axis, and glucose metabolism. The details ofeach disease are discussed below.

Hypothalamic-pituitary disorders
Hypothalamic-pituitary disorders were experienced by
20% of participants after COVID-19 or SARS-CoV2
vaccination, respectively, indicating that it is one of themost common endocrine disorders in these conditions.
The majority of these conditions were adrenal insuffi‐
ciency. There are numerous reports of adrenal insuffi‐
ciency after COVID-19 infection [21-23]. In many cases,
the etiology (primary vs. secondary to hypothalamicpituitary dysfunction) was unknown because many cases
lack detailed evaluation of the HPA axis. In this study,

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COVID-19 and endocrine care in Japansecondary was the most common. On the other hand,
there were a few responses for primary, and there werealso responses such as “adrenal insufficiency” for which
the etiology could not be determined, suggesting that pri‐mary adrenal insufficiency should also be kept in mind.
It is possible that the use of GCs and ritonavir (a potent
CYP3A4 inhibitor) for COVID-19 treatment may have
had an effect, but since we did not investigate the treat‐ment of the patients in this study, we cannot say for surethat COVID-19 and HPA axis modulation were directly
causally related. Further investigation is needed.
Vaccination is a known trigger for adrenal insuffi‐
ciency [24], and there are some reports of adrenal insuf‐
ficiency following SARS-CoV2 vaccination [25, 26]. It
is unclear whether the risk is higher in the SARS-CoV2
vaccine, but it is noteworthy that about the same numberof participants experienced it as those associated with
COVID-19. About 40% of participants reported that the
COVID-19 pandemic had negative effects on their prac‐
tice of hypothalamus-pituitary and adrenal diseases, andfew reported positive effects. The most common reason
for this was related to GC replacement. The issue of GC
replacement is discussed below.
It has been reported that concomitant central diabetes
insipidus (DI) with hypopituitarism is a risk for mortality
in acutely hospitalized patients [27]. In all patients withcentral DI admitted to the hospital with COVID-19, con‐sultation with an endocrinologist is recommended [28].
In this survey, few participants experienced difficulties inmanaging DI related to COVID-19. This may suggestthat the most important aspect of DI management for
COVID-19 patients is to consult an endocrinologist.
With regard to surgical treatment of pituitary tumors,
14.1% of participants experienced a discontinuation ordelay in surgery for cases indicated for surgery, and13.1% of participants reported a decrease in the numberof surgical cases. The most common reason for thedecrease was limited use of operating rooms. This wasthought to be due to the fact that nasal surgery is posi‐tioned as a treatment with a high risk of spreading infec‐
tion [29]. Salmon et al. analyzed pituitary surgery
outcomes at 2 years before and after COVID-19 from the
TriNetX database and reported that the number ofsurgeries decreased after COVID-19, but the number of
perioperative complications remained the same [30].
Endocrinological remission and relapse rates have notbeen evaluated and await further analysis.

Thyroid diseases
Thyroid diseases were a common area of examination
for participants who encountered abnormalities follow‐
ing COVID-19 infection or vaccination. This study
identified 228 cases where participants thought that11

autoimmune thyroid diseases like Graves’ disease andsubacute thyroiditis either worsened or emerged due to
COVID-19 infection or vaccination. While there havebeen numerous reports of these conditions following
COVID-19 infection or vaccination [31-33], it remains
unclear if there is a definitive increase in frequency. The
high number of reports could be influenced by thewidespread prevalence of COVID-19 and high vaccina‐tion rates.
Although there were a substantial number of patientswith Graves’ disease and subacute thyroiditis, this study
suggests that the negative impact on medical care due to
COVID-19 infection were not as severe compared toother areas in endocrinology. As much as 30% of partici‐
pants reported difficulties in managing Graves’ disease,with the main issue being access to medical care, includ‐ing continued treatment and medication therapy. Sub‐
acute thyroiditis, presenting with fever, is considered torequire medical attention in the context of COVID-19
infection, but the struggle with disease management was
not significantly high at 3%. Batman et al. reported in
the Thyroiditis Related to SARS-CoV-2 vaccine andCovid-19 (THYROVAC) study [34] that the course of
subacute thyroiditis following COVID-19 infection or
vaccination is no different from conventional subacutethyroiditis. This suggests that patients with subacute thy‐roiditis may be manageable with the usual treatment andobservation protocols.
Regarding surgical treatment of thyroid tumors, 25%of participants reported negative effects on benign nod‐ules, while 22% reported negative effects on malignant
tumors due to the COVID-19 pandemic. There was no
significant difference between benign and malignant
tumors. The reasons for these negative effects varied.
Responses in this study indicating that surgical treat‐ment, which was hindered by the COVID-19 pandemic,
was more prevalent for malignant tumors compared tobenign nodules. On the other hand, 18% of participants
reported a decrease in surgeries for benign nodules,
while 13% of participants reported a decrease for malig‐nant tumors, indicating a tendency to postpone surgeries
more for benign nodules. Generally, thyroid tumors, even
if malignant, have a favorable prognosis, and delaying
surgery is not perceived as detrimental, especially for
benign nodules. A retrospective analysis of data from the
National Cancer Database (USA) from 2004 to 2016
reported that prolonged waiting periods for thyroid can‐cer surgery led to a decrease in 5-year survival rates [34].
However, thyroid cancer surgeries during the COVID-19
pandemic experienced only a short delay (median 62days, 34–99 days), with little to no impact within that
range [35]. In the future, it is desirable to investigate theincrease in waiting days for thyroid surgery and its

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Manaka et al.

impact on prognosis in Japan. Another report from the
USA indicates a decrease in the number of thyroid surg‐eries since early 2020, and as of December 2022, inpa‐
tient surgery numbers have not yet recovered [36]. Thismay be attributed not only to restrictions on operating
room usage but also potentially affecting diagnoses andlong-term surgical numbers. Investigating the impact ofdelayed diagnoses is also recommended for future study.

Parathyroid diseases and osteoporosis
Among participants who encountered abnormalities
following COVID-19 infection or vaccination, very few
reported examining parathyroid diseases. Additionally,
only 14% of participants reported negative effects on the
management of parathyroid disease due to the
COVID-19 pandemic. The primary factor for these nega‐tive effects was difficulty in diagnosing parathyroid dis‐ease, with the second factor being hindered surgicaltreatment. The most common reason for decreased sur‐geries was restrictions on operating room usage. Some
reports from the USA [35, 36] suggest that among sur‐geries in the endocrine field, parathyroid diseases weresignificantly affected by the COVID-19 pandemic. How‐ever, in Japan, it seems that participants did not perceive
significant impact. This may be attributed to the rarity ofparathyroid cancer and the relatively low occurrence ofprimary hyperparathyroidism with symptomatic hyper‐
calcemia in recent years. Additionally, symptomatic
hypercalcemia can be managed with calcimimetics, suchas cinacalcet or evocalcet. As mentioned in one reportfrom the USA, the number of surgeries has not yet
recovered as of December 2022, similar to thyroid sur‐geries [36]. This suggests that delayed diagnoses may be
impacting the situation, emphasizing the importance ofinvestigating the impact of delayed diagnoses for future
study. When focusing on musculoskeletal health, 22% ofparticipants reported negative effects on the managementof osteoporosis due to the COVID-19 pandemic. The
majority of the reasons were related to issues with medi‐
cal access, such as difficulties in diagnosis and treatment.
Since osteoporosis patients are predominantly elderly,
and they largely overlap with the group at higher risk ofsevere complications from COVID-19 infection, thismay have been one of the factors contributing toworsened access to healthcare.
Adrenal diseases and hypertension
About half of the participants reported that COVID-19
had a negative impact on their practice for hypertension.
The main reasons for this were attributed to reduced
access to medical care, such as delayed diagnosis,
delayed initiation of treatment, and difficulties in contin‐uing treatment. Regarding the practice of primary aldo‐

steronism, 22% of the participants indicated that there
was a negative impact, mainly due to reduced access to
medical care. In the USA, it has been reported that out‐
patient visits were reduced during a COVID-19 pan‐demic, mainly due to fear of infection [37], and thatblood pressure control worsened in hypertensive patientsduring the pandemic [38]. On the other hand, some
reports indicate that, although the COVID-19 pandemic
led to a decrease in visits by hypertensive patients, there
was no significant change in blood pressure control [39].
It seems certain that an infectious disease epidemic leads
to a decrease in the number of hypertensive patients
seen, but whether this leads to a worsening of hyperten‐sion may depend on other factors, such as the number ofprescription days and the use of telemedicine [40].
As mentioned in the section on hypothalamic-pituitarydiseases, adrenal insufficiency is one of the most com‐mon endocrine disorders associated with COVID-19.
Sixteen percent of the participants indicated that the
COVID-19 epidemic increased the frequency of adrenal
insufficiency treatment mainly due to the development ofadrenal insufficiency caused by COVID-19. There havebeen case reports of adrenal insufficiency related to acutevascular complications (e.g., bleeding/thrombosis) after
COVID-19 [22, 41, 42], but in general, adrenocortical
function is reported to be preserved in COVID-19
patients [43]. Therefore, it seems more reasonable toassume that the adrenal insufficiency experienced in
COVID-19 is a patient with potentially impaired HPA
axis function that is manifested by the burden of
COVID-19 infection. In this sense, the issue of steroid
coverage during COVID-19 infection in patients withadrenal insufficiency is even more important. Indeed,
16% of the participants faced challenges with steroid
coverage. When encountering a physical stress, such as
an infection, a “stress dose” of GC beyond the physio‐
logic dose is necessary to avert adrenal crisis. Carosi et
al. reported that the severity of COVID-19 in patients
instructed and compliant with GC escalation during
infection did not differ from infected patients without
adrenal insufficiency [44]. It is unclear whether the riskof adrenal insufficiency is higher in the SARS-CoV2
vaccine, but in this study, the number of participants who
experienced adrenal insufficiency at the time of
COVID-19 infection and at the time of vaccination was
similar. The dose requirement for GC administration dur‐ing the peri-COVID-19 vaccination period in patientswith adrenal insufficiency is unclear. Bando et al.
reported that among adrenal insufficiency patients on GC
supplementation, only 8.3% required an increase in GC
supplementation after vaccination in the first dose and27.5% in the second dose, and none of the patients who
did not receive a GC dose escalation developed adrenal

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COVID-19 and endocrine care in Japan

crisis after vaccination [45]. In this study, more than halfof the participants did not explain to their patients about
increasing the GC dose in the event of COVID-19 infec‐
tion, and about a quarter of the participants did not men‐tion increasing the GC dose in the event of an adverse
reaction after vaccination. Consensus building withpatients regarding emerging viral infections, manage‐
ment of increased GC requirements at the time of vacci‐
nation, and supplemental doses is important.

Diabetes mellitus and obesity disease
The percentage of participants who reported that the
COVID-19 pandemic had negative effects on their prac‐
tice was as high as 86% for diabetes mellitus and 72%
for obesity disease. The most common reason given for
the negative effects was that it interfered with diet andexercise therapy. This is because many diabetic andobese patients were unable to exercise outdoors during
the pandemic, and spent more time at home and wereprone to snack more due to stress and other factors [46].
Many participants also reported the changes in their hos‐pital environment such as longer intervals between
patient’s visits, the start of telephone consultations, andthe discontinuation of diabetic patient meetings and dia‐betes classes for the patients. A longitudinal study con‐ducted in Tokyo, comparing the pre-pandemic andpandemic periods, reported that there was a significant
increase in delayed consultations and prescriptions dur‐ing the pandemic period [47]. This result and the reports
from other countries [15] support the results of this ques‐tionnaire survey. The impact of the change in outpatientcare on disease management was not clear in this survey,
and further investigation is needed.
On the other hand, only a small number of participants(28%) responded that the COVID-19 pandemic had posi‐tive effects. However, the text-mining analysis revealed
that many of them responded that the patient’s lifestyle
improved as they ate out less and socialized less withothers, indicating that the restrictions on going out due tothe COVID-19 pandemic was beneficial in some aspects
in the treatment of diabetic patients. In addition, some
respondents indicated that the pandemic has led to
expansion of video and telephone telemedicine. Remoteconsultations were said to be compatible with the treat‐ment of lifestyle-related diseases such as diabetes[16-18], and the use of remote consultations are expected
to expand in the future.
Diabetic patients and obese patients are at risk forsevere COVID-19, and diabetes and obesity are two of
the chronic diseases that are significantly affected in
COVID-19 infection [48].
In fact, about half of the participants in the survey had
experienced moderate to severe COVID-19 infections indiabetic patients. More than half of the participants had
also experienced cases in which the infection madeglycemic control difficult. The number of physicians
who had experienced severe infections in obese patientswas lower than in diabetic patients, but this may be dueto the difference in the number of patients attended asobese versus the number of patients attended as diabetic,
because diabetic patients who are obese are treated only
as diabetics and not as obese patients.
There were many diabetic patients who had hyper‐
glycemia associated with corticosteroid administration
for COVID-19 pneumonia and who developed hyper‐
glycemic crisis such as DKA and HHS associated with
the infection. Various cases of hyperglycemic crisis has
also been reported [49, 50], and hyperglycemia without
diabetes associated with COVID-19 infection and thedevelopment of new diabetes mellitus with the infection
are also under discussion [51]. Hyperglycemia is an
important prognostic factor in COVID-19 infection andways to prevent it need to be considered, such as further
education for diabetic patients about sick day and theestablishment of a hyperglycemia prevention protocol for
COVID-19 treatment.

Dyslipidemia and hyperuricemia
It has been suggested that the home-centered lifestyle
has had negative effects on the treatment of dyslipidemia
and hyperuricemia as well as diabetes and obesity. Thereis a report that flares were 9 times more frequent during
pandemic in gout patients, and also that they had
increased urate levels [52]. There is also an interesting
review that gout patients are likely to be at an increased
risk of poor outcomes after COVID-19 infection due tocomorbid cardiometabolic conditions. The effects ofchronic hyperuricemia and the hyperinflammatory state
induced by gout itself may also play a role. There is arisk of worse prognosis after COVID-19 infection due tocoexisting cardiovascular disease, which may be influ‐
enced by inflammation associated with chronic hyper‐
uricemia and gout attacks [53]. Reports on dyslipidemia
and hyperuricemia and COVID-19 infection are still not
many worldwide, and further accumulation of data isrequired.

Conclusion
This study aimed to elucidate the impact of the ongo‐
ing COVID-19 pandemic, which has lasted for over three
years, on the diagnosis and treatment of endocrine andmetabolic disorders in Japan. To achieve this, a nation‐
wide survey targeting board-certified endocrinologists,
conducted by the Japan Endocrine Society, focused on
the current situation and challenges in clinical practice.

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Manaka et al.

There is no precedent for such a large-scale anddetailed nationwide survey specifically targeting boardcertified endocrinologists with a focus on challenges inthe diagnosis and treatment of endocrine and metabolic
disorders when facing unpredictable emerging infectious
diseases. The scientific extraction of these problems is
expected to provide valuable insights for establishingrational and scientifically responsive measures for poten‐
tial future outbreaks of emerging and re-emerging infec‐
tious diseases, contributing to the development of a morerobust healthcare system.
The endocrinologists who experienced cases withsome form of endocrine and metabolic disorders fol‐lowing the COVID-19 infection or vaccination
exceeded 30%. Particularly in thyroid diseases, glu‐
cose metabolism disorders/diabetes mellitus, andhypothalamic-pituitary disorders, a significantly higher
tendency was observed compared to other endocrine andmetabolic disorders, marking an important new finding.
Furthermore, the endocrine and metabolic disorders
with particularly high rates of severe cases or fatalities
due to COVID-19 infection were diabetes and obesity,
which were compatible with previous reports both
domestically and internationally.
Through this study, several underlying challenges in
the routine diagnosis and treatment of endocrine andmetabolic disorders have come to light. The effective
combination of remote consultations with in-person
visits to optimize the frequency of examinations andcheck-ups has the potential to bring significant benefits
not only during infectious disease outbreaks but also in
non-emergency times, especially in the management of
endocrine and metabolic disorders that often requireongoing care.
This study has several limitations of note. This study
specifically targets specialists in endocrine and metabolic
disorders and may not directly apply to general medical
practice. This study is a survey targeting only the subjec‐
tive opinions of physicians, and there has been no con‐firmation of consistency with objective indicators or
evaluations from sources other than physicians.
Although a “complete survey” was initially assumed forthe survey procedure, the response rate from endocrinol‐
ogists at hospitals was higher than the response rate fromendocrinologists at clinics, potentially introducing asample bias. Based on the sampling surveillance on thefacilities of the target population, it appears that there
were relatively fewer respondents from clinics comparedto other facilities. There might be biases, such as special‐ists who participated in this study being from facilities
that accepted patients hospitalized due to COVID-19 andhad more opportunities to treat patients with endocrine

and metabolic disorders related to COVID-19. In addi‐tion, there were regional differences in response rates.
Compared to the facility location of the entire target pop‐
ulation, the response rate was lower in the Kanto region
and higher in the Chubu and Kyushu regions. Regarding
multiple responses from physicians within the samefacility, no weighted correction has been made toaccount for facility-dependent factors. Additionally,
there is a possibility that factors such as the age, gender,and geographic region of the respondents may not fully
represent the overall subjects due to relying on voluntary
responses. However, considering that there may be
several more waves of COVID-19 before the healthcare
system can fully return to normal, the insights obtained
from this survey are helpful in contributing to ensuring
appropriate healthcare provision for patients withendocrine and metabolic disorders during new waves of
COVID-19, and ultimately in conditions where medical
access may be limited due to future outbreaks of emerg‐ing or re-emerging infectious diseases.

Acknowledgements
The authors are grateful to all members of the Japan
Endocrine Society for their participation in this study andto the Secretariat of the Japan Endocrine Society for theiradministrative support of this study.

Disclosure
Funding statement
This work was supported by MHLW Research on
Emerging and Re-emerging Infectious Diseases and
Immunization (Program Grant Number JPMH21HA2011).

Author Disclosure Statement
The authors state that they have no conflicts of interest
related to this study.
K.H., A.S., N.M., N.S.-A., and H.M. are members ofEndocrine Journal’s Editorial Board.

Author Contribution
H.M. and H.A. designed the study. T.U. performed
administrative tasks including an ethical review. All
authors participated in compiling and revising the ques‐tionnaire. K.M., S.K., R.S., and H.Y. analyzed the data
and wrote the initial draft, and H.M., N.S.-A., H.A., and
M.F. edited the manuscript. All authors reviewed andapproved the final draft of the manuscript.

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COVID-19 and endocrine care in Japan

15

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