Shinshu M ed J, 61⑷ :205〜215, 2013

Serum High‑density Lipoprotein Cholesterol Level andLifestyle Habits among Japanese Junior High School Students
M inoru HONGO ＊, Hiroya HIDAKA , Shigeko SAKAGUCHI , Keisuke NAKANISHI
Fumiko TERASAWA , Motoki ICHIKAWA , Naoko HIROTA , Goro TSURUTA
Naoki TANAKA , Atsushi IZAWA , Yoshikazu YAZAKI , Uichi IKEDA , Kenichi KOIKE
on behalf of the Investigators of the Study Project on Prevention of
M etabolic Syndrome among Children, Adolescents, and Young Adults in Shinshu
1)
2)
3)
4)
5)
6)
7)
8)
9)

Department of Cardiovascular Medicine, Shinshu University School of Health Sciences
Department of Clinical Laboratory Medicine, Shinshu University School of Health Sciences
Department of Nursing, Shinshu University School of Health Sciences
Department of Pediatrics, Shinshu University School of Health Sciences
Faculty of Human Health Science, Matsumoto University
Department of Pediatrics, Shinshu University School of Medicine
Department of Gastroenterology, Shinshu University School of Medicine
Department of Cardiovascular Medicine, Shinshu University School of Medicine
Department of Cardiovascular Medicine, Saku General Hospital

Aim :We examined the relationship between serum high‑density lipoprotein cholesterol (HDL‑C) level andlifestyle habits among Japanese junior high school students.
Methods:Between April 2006 and M arch 2009,we conducted a cross‑sectional study of 1064 Japanese juniorhigh school students (570 boys and 494 girls,aged 12.1 to 15.0 years)who had annual school health examinations
in Nagano Prefecture. They were divided into 4 groups according to HDL‑C quartiles.
Results:There was a signiﬁcant increase in the ratio of waist circumference to body height, percentage ofbeing overweight, triglyceride, non‑HDL‑C, the ratio of low‑density lipoprotein cholesterol to HDL‑C, anduric acid in the lowest quartile of HDL‑C compared with the highest quartile in both genders.Fasting plasma
glucose was also signiﬁcantly increased in the lowest quartile compared with the highest quartile in boys.With
regard to lifestyle habits,the ratios of the students who were often commuting to and from school by car,did
not like exercise, did not do sports outside of school, and watched television during meals were signiﬁcantly
higher in the lowest quartile of HDL‑C compared with the highest quartile in both genders.
Conclusions: Serum HDL‑C level was associated with reduced daily physical activity among junior highschool students.This study may provide insights into the role of HDL‑C in the school screening system for thedevelopment of more eﬀective educational programs on the prevention of lifestyle‑related diseases in theJapanese population of school children. Shinshu Med J 61 : 205 ―215, 2013
(Received for publication January 8, 2013;accepted in revised form April 11, 2013)
Key words:high‑density lipoprotein cholesterol, Japanese junior high school students, lifestyle habits

Introduction

low‑density lipoprotein cholesterol (LDL‑C) level
and the risk of coronary heart disease (CHD) in

A number of large‑scale clinical trials haveadults.M any epidemiological studies have revealed

demonstrated an association between a high serum

a consistent inverse association between high‑density lipoprotein cholesterol (HDL‑C) level and theCorresponding author:Minoru Hongo
Department of Cardiovascular Medicine,Shinshu University School of Health Sciences, 3‑1‑1 Asahi,risk of CHD events and prognosis, independent of
LDL‑C, in the general population of adults.

Matsumoto, Nagano 390‑8621 Japan

Furthermore, several autopsy studies, such as theE‑mail:hongo＠shinshu‑u.ac.jp

Pathological Determinants of Atherosclerosis in

No. 4, 2013

205

Hongo.Hidaka.Sakaguchi et al.

Youth (PDAY) study

and the Bogalusa Heart

1 to 15.0 years)who had annual school health exami-

Study ,have reported that the presence and extent

nations at 3 schools in the various regions (urban,of atherosclerotic lesions in the aorta and coronaryrural, and mountain communities) of Nagano Pre-

arteries in young to middle‑aged adults who had

fecture. After written informed consent had beendied of accidental causes are closelycorrelated withobtained from both the students and their parents,

cardiovascular (CV) risk factors measured during

the students underwent measurements of resting

life. In addition, investigations using carotid ultra-

systolic and diastolic blood pressure (SBP, DBP),

sound in young and middle‑aged adults have pointed

and waist circumference (WC) as well as bodyout a positive relationship between childhood andheight (BH) and weight, and provided overnight

adolescent CV disease risk and subclinical measures

fasting venous blood samples.Each participant wasof atherosclerosis in adulthood. Based on these

then asked to complete a simple 12‑item self‑ad-

results,it is well established that the atherosclerotic

ministered questionnaire addressing lifestyle fac-process begins in childhood and progresses gradu-

tors, such as dietary patterns and habits and physi-

ally through adolescence to young adulthood into

cal activity, as well as the co‑existence of car-middle age,and that high LDL‑C and low HDL‑C indiometabolic risk factors, including dyslipidemia,

childhood are associated with an increased risk of

impaired glucose tolerance, and hypertension. The

the development of atherosclerosis and future CV

study protocol was approved by the Medical Ethics

disease in adulthood

Committee of Shinshu University School of Medi-.

We have previously reported that the prevalenceof young Japanese patients with CHD is increasingcine (Nos. 1598, 1711, and 1712).
Measurementswith a higher rate of onset during the summer

WC was measured at the level of the umbilicus

months , and that childhood obesity and a lack ofusing a measuring tape,and then the ratio of WC toregular physical activity are the most important

BH (WC/BH ratio) was derived. Percentage ofindependent risk factors for CHD events . Our

being overweight (POW) was calculated from anrecent observations have also exhibited a strong

age‑height‑related standard of weight for healthy

association between serum uric acid level and car-Japanese children. The POW was deﬁned as per-diometabolic risk factors

and between nonalco-

centage of weight diﬀerence from the standard

holic fatty liver disease and obesity and lifestyleweight. BP was determined after a 10‑min rest in

habitsamong Japanese junior high school stu-

the sitting position using a mercury‑gravity

dents. Thus, it would be more eﬀective to start tosphygmomanometer.All laboratory analyses of thecontrol the risk factors as early as possible in life.

blood samples, including serum concentrations ofHowever,there have been only a few reports on the

total cholesterol (TC), triglyceride (TG), and uricrelationship between HDL‑C and lifestyle habits

acid (SUA), fasting plasma glucose (FPG), andamong Japanese school children.The aim of thehemoglobin (Hb) A , were performed using stan-present study was to examine the relationshipdard methods. Serum HDL‑C level was measured

between serum HDL‑C level and lifestyle habits inby the direct method in 3 laboratories,in which thea sample of healthy Japanese junior high school

accuracy was strictly managed and standardized

students living in Nagano Prefecture.

among the laboratories. Serum LDL‑C was calcu-

Methods
Study design

lated using Friedewaldʼs equation,except for serum
TG level ＞ 400 mg/dL, and non‑HDL‑C level was
calculated by subtracting the HDL‑C from the TC

Between April 2006 and M arch 2009,we conduct-

concentration. The LDL‑C/HDL‑C ratio was thened a cross‑sectional study of 1064 Japanese juniorderived. Measurement of lipids and FPG was car-high school students (570 boys and 494 girls,aged 12.

ried out in the participants who had fasted 12 hours

206

Shinshu Med J Vol.61

HDL‑C and lifestyle habits

or more.The value of HbA

was described accord-

Statistical analysis

ing to the criteria of the National Glycohemoglobin

Continuous variables with normal distribution

Standardization Program .All participants had nowere expressed as mean ± SD and those with non‑chronic diseases and were receiving no medication

normal distribution, such as TG, were presented asin the present study.

the median.The diﬀerence of categorical variables,

Deﬁnition of cardiometabolic risk factors
Abdominal obesity was deﬁned as a WC

including lifestyle habits,was examined with thechi‑

80 cm

square test or Fisherʼs exact test. The signiﬁcance

0.5 . Hypertriglycer-of continuous variables, such as age, WC, WC/BH

idemia was determined by serum concentration ofratio, POW, SBP, DBP, HDL‑C, TG, LDL‑C, non

120 mg/dL . Low HDL‑C was identiﬁed by

HDL‑C, LDL‑C/HDL‑C ratio, FPG, HbA , andand/or WC/BH ratio
TG

serum HDL‑C ＜ 40 mg/dL

and increased fasting

SUA, between groups was analyzed by using an

100 mg/dL . In

unpaired t‑test or an analysis of variance for

addition,we adopted the criteria of hypertension in

repeated measures and Newmann‑Keuls post hoc

Japanese junior high school students at a medical

test. All analyses were performed with the SPSS

check‑up recommended by the Japanese Society ofsoftware Version 12.0 for Windows (SPSS,Chicago,

Hypertension,in which hypertension was deﬁned as

IL, USA) and a p value of ＜ 0.05 was considered

glucose was deﬁned as FPG

SBP

140 mmHg and/or DBP

and SBP85 mmHg in boys

135 mmHg and/or DBP

statistically signiﬁcant.

80 mmHg in

Results

girls .M etabolic syndrome in the pediatric setting
was identiﬁed by the presence of abdominal obesity

The data were analyzed among boys and girls

in association with at least 2 of the 3 conditions,separately, and gender‑speciﬁc quartiles of HDL‑C

such as hypertriglyceridemia and/or low HDL‑C,

levels were used because they were observed tohigh BP which was deﬁned as SBP

125 mmHg

approximate a normal distribution, as shown in

70 mmHg, and elevated FPG levels

Fig. 1.HDL‑C levels were classiﬁed into the follow-

and/or DBP

55 mg/dL (mean 49 mg/dL),according to the criteria proposed by a Task Forceing 4 categories:(1)ﬁnanced by the Ministry of Health, Welfare, and(2)56 to 63 mg/dL (mean 60 mg/dL),(3)64 to 73 mg/

Labor Science Research Grants in Japan .

dL (mean 68 mg/dL),and (4)74 mg/dL (mean 81

Fig. 1 Distribution of serum high‑density lipoprotein cholesterol concentration in boys and girls

No. 4, 2013

207

Hongo.Hidaka.Sakaguchi et al.
Table 1 Baseline Characteristics
Boys
Number of subjects

Girls

570

494

Age (yrs)
WC (cm)WC/BH ratio

13.2±0.6
68.0±7.9
0.42±0.04

13.1±0.667.5±6.8
0.43±0.04

POW (%)

1.0±14.3
113±1263±10

0.4±13.9108±1163±9

63(38‑122)
88±20
65±13

67
(36‑110)
94±24
66±13

100±121.36±0.4288±8
5.4±0.3

108±131.42±0.4787±75.3±0.3

5.7±1.1

4.5±0.8

Systolic BP (mmHg)
Diastolic BP (mmHg)
TG (mg/dL)(95% CI)LDL‑C (mg/dL)
HDL‑C (mg/dL)
non‑HDL‑C (mg/dL)
LDL‑C/HDL‑C ratio
FPG (mg/dL)
Hemoglobin A
SUA (mg/dL)(%)

p value

0.063
0.301
＜0.001
0.495＜0.001
0.971＜0.001＜0.001
0.153＜0.001
0.008
0.217
0.076
＜0.001

Data are presented as numbers or mean±SD or medians.
WC, waist circumference;BH, body height ;POW, percentage of being overweight ;BP, bloodpressure; TG, triglyceride; LDL‑C, low‑density lipoprotein cholesterol; HDL‑C, high‑density
lipoprotein cholesterol;FPG, fasting plasma glucose;SUA, serum uric acid.

mg/dL)for boys and (1)56 mg/dL (mean 51 mg/

est quartile (Table 2).The prevalence of abdominal

dL),(2)57 to 64 mg/dL (mean 60 mg/dL),(3)65 to 74

obesity, hypertriglyceridemia, and increased FPG

mg/dL (mean 69 mg/dL),and (4)was signiﬁcantly greater in the lowest quartile of

75 mg/dL (mean

82 mg/dL)for girls.

HDL‑C compared with the highest quartile (Table

M etabolic syndrome was found in only 5 (0.5 %)3).In girls,there was a graded decrease in LDL‑C/of the students (4 boys and 1 girl). The highest

HDL‑C ratio and a signiﬁcant increase in WC,WC/

number of the students was located at a HDL‑C

BH ratio, POW, TG, non‑HDL‑C, and SUA in thelevel between 60 mg/dL and 65 mg/dL in bothlowest quartile of HDL‑C compared with the high-genders, and only 11 (1.0 %)(8 boys and 3 girls) of

est quartile (Table 2).The prevalence of abdominal

the students showed low HDL‑C (Fig. 1). SBP andobesity and hypertriglyceridemia was signiﬁcantly

SUA were signiﬁcantly higher and WC/BH ratio,

increased in the lowest quartile of HDL‑C compar-

TG,LDL‑C,non‑HDL‑C,and LDL‑C/HDL‑C ratio

ed with the highest quartile(Table 3).No signiﬁcantwere lower in boys than in girls (Table 1). POW,

diﬀerence was found in the prevalence of hyperten-

HDL‑C, FPG, and HbAsion or high LDL‑C among quartiles of HDL‑C in

did not diﬀer between

genders (Table 1).The lowest 5th percentileofHDL‑

both genders (Table 3).

C level was 40.0 mg/dL for boys and 40.3 mg/dL

According to HDL‑C quartiles,there was a grad-for girls.There was no signiﬁcant diﬀerencein HDL‑

ed increase in the ratio of students who were doing

C level among students from the 3 diﬀerent areas.

sports outside of school in both genders and a

In boys, TG and LDL‑C/HDL‑C ratio showed agraded decrease in the ratio of students who were

graded decrease according to HDL‑C quartiles.

often commuting to and from school by car in girls

There was a signiﬁcant increase in WC, WC/BH(Table 4).The ratios of the students who were often

ratio, POW, non‑HDL‑C, FPG, and SUA in thecommuting to and from school by car, did not likelowest quartile of HDL‑C compared with the high-exercise,and watched television (TV)during meals

208

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HDL‑C and lifestyle habits
Table 2 Gender‑speciﬁc Baseline Characteristics According to HDL‑C Quartiles
Quartiles of HDL‑C
Q1

Q2

Q3

Q4

55
143
13.3±0.770.4±10.1
0.43±0.06
6.0±18.4

56‑63149
13.3±0.7
66.7±7.5
0.42±0.03
0.5±13.2

64‑73
137
13.2±0.7
66.6±6.4
0.42±0.03‑1.1±13.07414113.2±0.667.1±8.5
0.42±0.05‑1.3±10.8113±1264±982(54‑122)113±1263±10

114±1163±10

114±1364±1151(38‑73)

Boys (n＝570)
Range of HDL‑C (mg/dL)
Number of subjects
Age (yrs)
WC (cm)WC/BH ratio
POW (%)
Systolic BP (mmHg)
Diastolic BP (mmHg)
TG (mg/dL)(95% CI)‑LDL C (mg/dL)
non‑HDL‑C (mg/dL)
LDL‑C/HDL‑C ratio
FPG (mg/dL)
Hemoglobin A (%)
SUA (mg/dL)

74

57

87±19
102±201.77±0.37
91±7
5.4±0.3
5.9 ±1.2(51‑112)89 ±22103±23
1.49 ±0.36
88±8
5.4±0.4
5.4±1.1(46‑91)88±19
98±201.29 ±0.29
88±7
5.4±0.3
5.5±1.1

89 ±2097±211.10±0.27
86±8
5.4±0.3
5.5±1.256125
13.2±0.7
69.0±7.4
0.44±0.04
3.0±14.9108±1057‑6412513.1±0.767.5±6.1
0.43±0.04
1.6±12.0
109 ±1065‑7412013.2±0.7
67.7±6.8
0.43±0.04
1.8±16.1
109 ±1175
12413.1±0.6
65.7±6.3
0.42±0.04‑3.3±11.9108±11

62±8

62±8

62±11

63±10

76
(53‑110)95±27112±231.86±0.4687±7
5.4±0.4

66(41‑97)91±27
107±251.52±0.4187±65.4±0.3

64(40‑93)92±29
106±271.34±0.3987±7
5.3±0.4

48(35‑79)93±28107±261.13±0.31
87±7
5.3±0.3

4.7±0.9

4.5±0.8

4.5±0.8

4.3±0.8

Girls (n＝494)
Range of HDL‑C (mg/dL)
Number of subjects
Age (yrs)
WC (cm)WC/BH ratio
POW (%)
Systolic BP (mmHg)
Diastolic BP (mmHg)
TG (mg/dL)(95% CI)LDL‑C (mg/dL)
non‑HDL‑C (mg/dL)
LDL‑C/HDL‑C ratio
FPG (mg/dL)
Hemoglobin A
SUA (mg/dL)(%)

p＜0.05, p＜0.01, and
p＜0.001 vs Q4. Data are presented as numbers or mean±SD or medians.
Abbreviations as in Table 1.

were signiﬁcantly higher in the lowest quartile of
HDL‑C compared with the highest quartile in both

Discussion

genders (Table 4).In the lowest quartile of HDL‑C,

The results of the present study in a school‑based

the prevalence of students who were often commut-

sample of Japanese junior high school students

ing to and from school by car was signiﬁcantly

demonstrated that serum HDL‑C level was as-

higher, and of those who liked exercise was lower,sociated with reduced daily physical activity. Thisin girls than in boys (Table 4).

study may provide insights into the role of HDL‑C
level in the school screening system for the development of more eﬀective educational programs on

No. 4, 2013209

Hongo.Hidaka.Sakaguchi et al.
Table 3 Prevalence of Cardiometabolic Risk Factors According to HDL‑C Quartiles
Quartiles of HDL‑C
Q1

Q2

Q3

Q4

Boys
Abdominal obesity
Hypertension
Hypertriglyceridemia
High LDL‑C
Increased FPG

16.9
1.5
11.8
0.7
13.1

6.5
0
9.4
2.2
5.4

5.8
0
0.7
1.3
2.9

6.4
0
0
0.7
2.9

Girls
Abdominal obesity
Hypertension
Hypertriglyceridemia
High LDL‑C
Increased FPG

14.7
0.9
12.1
1.7
4.3

6.5
0.8
8.9
3.2
3.2

6.8
2.2
5.2
4.5
3.0

4.0
0
2.4
4.8
3.7

The numbers indicate prevalence of each variable (percentages).
p＜0.05 vs Q4, p＜0.01 vs Q4, and
p＜0.001 vs Q4.
Abbreviations as in Table 2.
Table 4 HDL‑C Level and Lifestyle Habits
Quartiles of HDL‑C
Q1

Q2

Q3

Q4

24 (16.8)
66 (46.2)
74 (51.7)
61 (42.7)
57 (39.9)
128 (89.5)
50 (35.0)
31 (21.7)
65 (45.5)
109 (76.2)
70 (49.0)
4 (2.7)17 (11.4)
64 (43.0)
76 (51.0)
61 (40.9)
53 (35.6)
115 (77.2)
50 (33.6)
25 (16.8)
31 (20.8)101 (67.8)
113 (75.8)
29 (19.5)

18 (13.1)
59 (43.1)
67 (48.9)55 (40.1)
45 (32.8)
103 (75.2)
43 (31.4)
22 (16.1)
18 (13.1)
96 (70.1)
109 (79.6)
43 (31.4)

17 (12.1)
60 (42.6)
67 (47.5)
54 (38.3)
44 (31.2)
102 (72.3)
40 (28.4)
21 (14.9)
14 (9.9)
94 (66.7)
126 (89.4)
75 (53.2)

Girls (n＝494)
Skipping breakfast ( 2 times/week)
17 (13.6)
Eating quickly
51 (40.8)
Drinking more than half of the broth with noodles
44 (35.2)
Consuming sweetened drinks every day
33 (26.4)
Eating a midnight snack ( 3 times/week)
39 (31.2)
Watching television during meals
107 (85.6)
Eating cakes/sweet rolls ( 3 times/week)
35 (28.0)
Eating convenience store lunches ( once/week)
16 (12.8)
Often commuting to and from school by car
73 (58.4) ,Playing computer games ( 1 h/day)
33 (26.4)
Liking exercise
24 (19.2) ,Doing sports outside of school
2 (1.6)16 (12.8)
51 (40.8)42 (33.6)30 (24.0)
38 (30.4)
99 (79.2)
35 (28.0)
13 (10.4)
59 (47.2)
27 (21.6)
63 (50.4)
12 (9.6)

13 (10.8)47 (39.2)
36 (30.0)26 (21.7)
37 (30.8)
98 (81.7)
31 (25.8)
15 (12.5)
24 (20.0)26 (21.7)
67 (55.8)
21 (17.5)

13 (10.5)
49 (39.5)
37 (29.8)
29 (23.4)
35 (28.2)
92 (74.2)
27 (21.8)
10 (8.1)
11 (8.9)25 (20.2)
77 (62.1)
39 (31.5)

Boys (n＝570)
Skipping breakfast ( 2 times/week)
Eating quickly
Drinking more than half of the broth with noodles
Consuming sweetened drinks every day
Eating a midnight snack ( 3 times/week)
Watching television during meals
Eating cakes/sweet rolls ( 3 times/week)
Eating convenience store lunches ( once/week)
Often commuting to and from school by car
Playing computer games ( 1 h/day)
Liking exercise
Doing sports outside of schoolp＜0.05, p＜0.01, and(percentages).

210

p＜0.001 vs Q4. p＜0.01 and

p＜0.001 vs Q1 in boys. Data are expressed as numbers

Shinshu Med J Vol.61

HDL‑C and lifestyle habits

prevention of lifestyle‑related diseases in thetile was not surprising because HDL‑C and otherJapanese population of school children.

cardiometabolic risk factors are the components of

HDL‑C and CV disease risk
HDL‑C possesses not only reverse cholesterol

metabolic syndrome .
HDL‑C and lifestyle habitstransport function but also several beneﬁcial biolog-

It is generally recognized that increased physicalical properties, including direct endothelial protec-

activity, cessation of smoking, weight loss, moder-tion, anti‑oxidation of LDL, and anti‑thrombotic,

ate alcohol intake, a diet rich in omega‑3 polyun-anti‑inﬂammatory,and anti‑apoptotic eﬀects,all of

saturated fatty acids, and a diet low in carbo-

which may contribute to protect against atheros-

hydrates are strategies for HDL‑C elevation andclerosis . Since the Framingham Heart Study , athat drugs that raise the HDL‑C level as the princi-

number of epidemiological studies have revealed apal pharmacodynamic eﬀect do not exist .In addi-

consistent negative association of HDL‑C level withtion, a frequent Japanese‑style diet, which is char-CV disease risk in adults in Western countries .

acterized by adequate total calories, increased

and all‑cause mortality

intake of ﬁsh and plant foods,and decreased intake

has also been inversely related to HDL‑C in theof carbohydrates and animal fat,has been shown toadult Japanese general population . A recent co-cause an elevation of HDL‑C level . A previous

hort study with 12 years of follow‑up in the malestudy in the Japanese population of fourth‑grade

Japanese population has identiﬁed lower HDL‑C aselementary school children demonstrated thatan independent risk factor for CHD .

compared with normal‑fat group,high‑fat children

The incidence of CHD

In the Japanese population of school children,were less physically active and consumed a larger

there was an increase in the prevalence of TC levelamount of food, which was associated with de-from 1960 to 1996 in the nation‑wide school healthcreased HDL‑C level .In contrast,a recent obser-

program conducted by the Ministry of Education,

vation revealed no change in HDL‑C level after

which was in parallel with an increase in obesity

dietary treatment combined with exercise treat-

during the same period . However, a recent study

ment in obese Japanese children aged 10.1 years oldon population‑based annual screening of ﬁfth‑grade

despite marked improvement of visceral fat andelementary school children in a regional district

other cardiometabolic risk factors,such as TG,TC,

from 1993 to 2008 observed no signiﬁcant change inand uric acid, and liver dysfunction . The discrep-

TC, non‑HDL‑C, or HDL‑C among school chil-ancies in the results might be due to the diﬀerences

dren . Okada et al. proposed new criteria of nor-in the study design,including the subjects and inten-

mal serum lipid levels among Japanese school chil-sity and duration of exercise. In the present study,

dren aged 9 to 16 years who were enrolled from 19

the ratios of the students who were often commut-

prefectures and received screening and care pro-ing to and from school by car,did not like exercise,grams for prevention of lifestyle‑related diseases

did not do sports outside of school,and watched TV

from 1993 to 1999, in which the level below the 5thduring meals were signiﬁcantly higher in the lowest

percentile of HDL‑C was deﬁned to be low and thequartile of HDL‑C level compared with the highest

cut‑oﬀvalue was determined as 40 mg/dL .In thequartile in both genders. It was of particular inter-

present study, the prevalence of HDL‑C ＜ 40 mg/

est that in the lowest quartile of HDL‑C level, thedL was only 1.0 %, but the value of the lowest 5th

prevalence of students who were often commuting

percentile of HDL‑C was consistent with the ﬁnding

to and from school by car was signiﬁcantly higher,

by Okada et al . The ﬁnding that students in theand of those who liked exercise was lower, in girls

lowest quartile of HDL‑C showed increased preva-

than in boys,despite an almost identical mean HDL‑

lence of abdominal obesity, hypertriglyceridemia,

C level. In contrast, no signiﬁcant relationship ofand increased FPG compared with the highest quar-other dietarypatterns or habits to HDL‑C level was

No. 4, 2013211

Hongo.Hidaka.Sakaguchi et al.

found among the school children. These ﬁndings

creased HDL‑C compared with control subjects andwere in accordance with a recent observation bythat the unfavorable lipid proﬁles might track

Yoshinaga, et al. that lifestyle conditions, such as

through adolescenceparticipation in school‑based extracurricular physi-

focused on not only physical activity but also thecal activities and TV‑watching time,were inversely

relationship between the lipid proﬁles and the birthcorrelated with HDL‑C level in Japanese healthy

weight as well as the catch‑up increase in weightadolescent high school students aged 15 to 18

early in life. Fourth, although central adiposity as

years , suggesting that a lower HDL‑C level ismeasured by WC has been associated with car-associated with reduced daily physical activity

diometabolic risk factors as well as fasting insulin

among school children. Aerobic exercise has beenlevel, independent of body mass index

reported to elevate HDL‑C level by 5‑10 %.

measurement of WC and POW is easily performed

Although its precise mechanism is unclear, in-in children,whether WC and POW or HDL‑C levelcreased activity of muscle lipoprotein lipase has

measurement might be better for identifying chil-been suggested as one of the possible contributing

dren at more risk metabolically and predicting

factors .

future CV disease remains to be elucidated.Finally,

Limitations and Implications.Thus,attention should be, andit would be expected that the prevalence of obesity

There were several limitations in the present

and other cardiometabolic risk factors substantiallystudy.First,because this is a cross‑sectional study,

varies in the diﬀerent regions of Japan. Thus, a

it remains unknown whether children with lower

nation‑wide prospective survey is required to verify

HDL‑C level may show changes in lipid proﬁles

the present ﬁndings of an association of lower HDL‑

following lifestyle modiﬁcations or develop future

C level with lifestyle habits in the entire Japanese

CV disease if they did not do so. To establish the

population of school children.

exact prognostic signiﬁcance of HDL‑C in the

It is important to recognize predictors of risk ofdevelopment of CV events among children, further

future atherosclerotic CV diseases for early detec-

longer follow‑up studies are required. Second, thetion and more eﬀective preventive measures in indi-

questionnaire was very simple and contained only

vidual children and adolescents. The results of the

12 items concerning lifestyle patterns.Furthermore,present study indicate that HDL‑C level is associat-

the association between HDL‑C and lifestyle habits

ed with daily physical activity among school chil-

was not adjusted for confounding factors, such as

dren.First of all,it is important to oﬀer educational

the magnitude of physical activity, in the present

opportunities that show the relationship between

study;such factors might inﬂuence the relationship,

lifestyle pattern, such as reduced daily physicalresulting in overestimation or underestimation in

activity,and unfavorable lipid proﬁles among junior

the results. Therefore, a more detailed analysis

high school students, particularly in girls, because

after adjustment by using multivariate analysis or

there was a signiﬁcant diﬀerence in the prevalence

stratiﬁed analysis is necessary for precise assess-of students who were often commuting to and fromment. Third, it has been reported that lower HDL‑

school by car and who liked exercise between bothC levels are accompanied by several conditions

genders in the lowest quartile of HDL‑C level.

other than reduced daily physical activity in chil-Children and adolescents with lower HDL‑C level

dren, such as exposure to environmental tobacco

can be considered as a special target group forsmoke

and maternal smoking in pregnancy . In

implementation of a family‑based repeated lifestyle

addition, several investigators have observed thatintervention, especially increased daily physicalchildren born small who are associated with post-

activity.

natal rapid weight gain haveincreased LDL‑C,LDL‑
C/HDL‑C ratio, and insulin resistance and de212

Shinshu Med J Vol.61

HDL‑C and lifestyle habits

all other members of the Study Project on Preven-

Acknowledgmentstion of Metabolic Syndrome among Children, Ado-

This study was supported by grants from the
Ministry of Welfare and Labor in Japan 2009 ‑2013

lescents, and Young Adults in Shinshu for theirvaluable suggestions and assistance.

(Nos. 21500650 and 24500813), the Special ResearchConﬂicts of Interest

Fund of the Vice‑chancellor of Shinshu University
2010‑2013, the Japanase Society of Child Health2009,and the Advanced Preventive Medical Center,

The authors declare no potential conﬂicts of interest.

Shinshu University Hospital 2009 ‑2013. We thankReferences
1) Gordon DJ,Probstﬁeld JL,Garrison RJ,Neaton JD,Castelli WP,Knoke JD,Jacobs DR Jr,Bangdiwala S,Tyroler
HA : High‑density lipoprotein cholesterol and cardiovascular disease: Four prospective American studies.
Circulation 79 :8‑15, 1989
2) Weverling‑Rijnsburger AWE, Jonkers IJAM , van Exel E, Gussekloo J, Westendorp RGJ :High‑density vs low‑densitylipoprotein cholesterol as the risk factor for coronaryarterydisease and stroke in old age.Arch Intern Med
163:1549 ‑1554, 2003
3) Kitamura A,Iso H,Naito Y,Iida M,Konishi M,Folsom AR,Sato S,Kiyama M ,Shimamoto T,Komachi Y :High‑density lipoprotein cholesterol and premature coronary heart disease in urban Japanese men.Circulation 89 :2533‑
2539, 1994
4) Okamura T, Hayakawa T, Kadowaki T, Kita Y, Okayama A, Ueshima H, the NIPPON DATA90 ResearchGroup :The inverse relationship between serum high‑density lipoprotein cholesterol level and all‑cause mortality
in a 9.6‑year follow‑up study in the Japanese general population. Atherosclerosis 184:143‑150, 2006
5) Satoh H, Tomita K, Fujii S, Kishi R, Tsutsui H :Lower high‑density lipoprotein cholesterol is a signiﬁcant andindependent risk for coronary artery disease in Japanese men. J Atheroscler Thromb 16:792‑798, 20096) M cGill HC Jr,McMahan CA,Malcolm GT,Oalmann M C,Strong JP :Eﬀects of serum lipoproteins and smoking
on atherosclerosis in young men and women :Pathobiological determinants of atherosclerosis in youth.Arterioscler Thromb Vasc Biol 17:95‑106, 1997
7) M cGill HC Jr, McMahan CA, Zieske AW, M alcolm GT, Tracy RE, Strong JP, for the Pathobiological Determinants of Atherosclerosis in Youth (PDAY)Research Group :Eﬀects of nonlipid risk factors on atherosclerosis inyouth with a favorable lipoprotein proﬁle. Circulation 103:1546‑1550, 2001
8) Newman WP III, Freedman DS, Voors AW, Gard PD, Srinivasan SR, Cresanta JL, Williamson GD, Webber LS,
Berenson GS : Relation of serum lipoprotein levels and systolic blood pressure to early atherosclerosis: The
Bogalusa Heart Study. N Engl J Med 314:138‑144, 1986
9) Berenson GS,Srinivasan SR,Bao W,Newman WP III,Tracy RE,Wattigney WA,for the Bogalusa Heart Study:
Association between multiple cardiovascular risk factors and atherosclerosis in children and young adults.N Engl
J Med 338:1650‑1656, 1998
10) Davis PH, Dawson JD, Riley WA, Lauer RM :Carotid intimal‑medial thickness is related to cardiovascular risk
factors measured from childhood through middle age:The Muscatine Study. Circulation 104:2815‑2819, 2001
11) Raitakari OT,Juonala M ,Kahonen M,Taittonen L,Laitnen T,M aki‑Torkko N,Jarvisalo M J,Uhari M ,Jokinen
E,Ronnemaa T,Akerblom HK,Viikari JSA :Cardiovascular risk factors in childhood and carotid intima‑media
thickness in adulthood :The Cardiovascular Risk in Young Finns Study. JAM A 290:2277‑2283, 2003
12) M cGill HC Jr, McMahan CA, Gidding SS : Preventing heart disease in the 21st century: Implications of the
Pathobiological Determinants of Atherosclerosis in Youth (PDAY)Study. Circulation 117:1216‑1227, 2008
No. 4, 2013213

Hongo.Hidaka.Sakaguchi et al.
13) Daniels SR, Greer FR, the Committee on Nutrition : Lipid screening and cardiovascular health in childhood.
Pediatrics 122:198‑208, 200814) Steinberger J, Daniels SR, Eckel RH, Hayman L, Lustig RH, M cCrindle B, M ietus‑Snyder M L :Progress andchallenges in metabolic syndrome in children and adolescents. Circulation 119 :628‑647, 200915) Azegami M, Hongo M, Yazaki Y, Yanagisawa S, Yamazaki A, Imamura H : Seasonal diﬀrence in onset ofcoronary heart disease in young Japanese patients:A comparison with older patients.Circ J 69 :1176‑1179,2005
16) Azegami M , Hongo M , Yanagisawa S, Yamazaki A, Sakaguchi K, Yazaki Y, Imamura H :Characteristics ofmetabolic and lifestyle risk factors in young Japanese patients with coronary heart disease:A comparison witholder patients. Int Heart J 47:343‑350, 200617) Hongo M , Hidaka H, Sakaguchi S, Nakanishi K, Ichikawa M , Hirota N, Tanaka N, Tsuruta G, Yazaki Y,
Kinoshita O, Ikeda U, Koike, K, on behalf of the Investigators of Study Project on Prevention of M etabolic
Syndrome among Children,Adolescents,and Young Adults in Shinshu :Association between serum uric acid levels
and cardiometabolic risk factors among Japanese junior high school students. Circ J 74:1570‑1577, 201018) Tsuruta G, Tanaka N, Hongo M, Komatsu M, Horiuchi A, Hamamoto K, Iguchi C, Nakayama Y, Umemura T,
Ichijo T,M atsumoto A,Yoshizawa K,Aoyama T,Tanaka E :Nonalcoholic fatty liver disease in Japanese juniorhigh school students:Its prevalence and relationship to lifestyle habits. J Gastroenterol 45:666‑672, 201019) Washino K, Takada H, Nagashima M , Iwata H : Signiﬁcance of the atherosclerogenic index and body fat inchildren as markers for future, potential coronary heart disease. Pediatr Int 41:260‑265, 1999
20) Togashi K,M asuda H,Iguchi K :Eﬀect of diet and exercise treatment for obese Japanese children on abdominal
fat distribution. Res Sports M ed 18:62‑70, 201021) Kashiwagi A, Kasuga M, Araki E, Oka Y, Hanafusa T, Ito H, Tominaga M, Oikawa S, Noda M ,Kawamura T,
Sanke T,Namba M,Hashiramoto M,Sasahara T,Nishio Y,Kuwa K,Ueki K,Takei I,Umemoto M,M urakami
M ,Yamakado M ,Yatomi Y,Hatsumi Ohashi H,Committee on the Standardization of Diabetes Mellitus‑Related
Laboratory Testing of Japan Diabetes Society:International clinical harmonization of glycated hemoglobin in
Japan :From Japan Diabetes Society to National Glycohemoglobin Standardization Program values.Diabetol Int
3:8‑10, 201222) Ozeki T, Satake E :Diagnostic criteria for metabolic syndrome and visceral adiposity in children. Adiposcience
4:359 ‑364, 2007 (in Japanese)23) Okada T,Murata M ,Yamauchi K,Harada K :New criteria of normal serum lipid levels in Japanese children :thenationwide survey. Pediatr Int 44:596‑601, 200224) The Japanese Society of Hypertension :Guidelines for the management of hypertension JSH2009. pp 83‑86, 2009
(in Japanese)25) Natarajan P, Ray KK, Cannon CP :High‑density lipoprotein and coronary heart disease. J Am Coll Cardiol 55:
1283‑1299, 201026) Gordon DJ,Castelli WP,Hjortland MC,Kannel WB,Dawber TR :High density lipoprotein as a protective factor
against coronary heart disease:The Framingham Study. Am J Med 62:707‑714, 197727) Iso H :Changes in coronary heart disease risk among Japanese. Circulation 118:2725‑2729, 200828) M urata M :Secular trends in growth and changes in eating patterns of Japanese children. Am J Clin Nutr 72(suppl):1379S‑1383S, 2000
29) Kouda K,Nakamura H,Nishio N,Fujita Y,Takeuchi H,Iki M :Trends in body mass index,blood pressure,andserum lipids in Japanese children :Iwata population‑based annual screening (1993‑2008).J Epidemiol 20:212‑218,
201030) Can AS, Uysal C, Palaoglu KE :Short term eﬀects of a low‑carbohydrate diet in overweight and obese subjects
with low HDL‑C levels. BMC Endocr Disord 10:18, 2010214

Shinshu Med J Vol.61

HDL‑C and lifestyle habits31) Hata Y, Nakajima K :Life‑style and serum lipids and lipoproteins. J Atheroscler Thromb 7:177‑197, 2000
32) Yoshinaga M, Hatake S, Tachikawa T, Shinomiya M, M iyazaki A, Takahashi H : Impact of lifestyles ofadolescents and their parents on cardiovascular risk factors in adolescents. J Atheroscler Thromb 18:981‑990,
201133) Thompson PD :What do muscles have to do with lipoproteins?Circulation 81:1428‑1430, 199034) Hirata K,Yamano Y,Suzuki H,M iyagawa S,Nakadate T :Passive smoking is associated with lower serum HDL‑
C levels in school children. Pediatr Int 52:252‑256, 201035) Ayer JG, Belousova E, Harmer JA, David C, Marks GB, Celermajer DSC : M aternal cigarette smoking is
associated with reduced high‑density lipoprotein cholesterol in healthy 8‑year‑old children.Eur Heart J 32:2446‑
2453, 2011
36) Fabricus‑Bjerre S,Jensen RB,Faerch K,Larsen T,M olgaard C,Michaelsen KM ,Vaag A,Greisen G :Impact ofbirth weight and early infant weight gain on insulin resistance and associated cardiovascular risk factors inadolescence. PLos One 6:e20595, 201137) Efstathiou SP, Skeva II,Zorbala E,Georgiou E,M ountokalakis TD :M etabolic syndrome in adolescence:Can it
be predicted from natal and parental proﬁle?The Prediction of Metabolic Syndrome in Adolescence (PREM A)
Study. Circulation 125:902‑910, 201238) Nadeau KJ,M aahs DM,Daniels SR,Eckel RH :Childhood obesity and cardiovascular disease:links and prevention strategies. Nat Rev Cardiol 8:513‑525, 201139) M aﬀeis C,Pietrobelli A,Grezzani A,Provera S,Tato L :Waist circumference and cardiovascular risk factors in
prepubertal children. Obes Res 9 :179 ‑187, 200140) Lee S, Bacha F, Gungor N, Arslanian SA :Waist circumference is an independent predictor of insulin resistancein black and white youths. J Pediatr 148:188‑194, 2006

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