bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of Extra-Renal CYP24A1 Expression for Maintaining Mineral Homeostasis
Authors: Shi Melody , Grabner Alexander , Wolf Myles
Published: May 2021

Calcium homeostasis involves a complex interplay between kidneys, parathyroid glands, intestine and bone. Specifically, 1,25(OH)2D3 is a key calciotropic hormone which stimulates intestinal calcium absorption. A growing body of evidence suggests that circulating levels of 1,25(OH)2D3 depend not only on its synthesis under the action of PTH in the kidneys, but also its catabolism by 24-hydroxylase, herein referred to as CYP24A1. The clinical importance of CYP24A1 has been demonstrated by human loss-of-function mutations, which lead to severe hypercalcemia due to exaggerated levels of 1,25(OH)2D3. Despite its growing importance, little is known about its tissue-specific contributions to normal vitamin D metabolism. To explore the physiology of CYP24A1 and delineate renal-specific effects of CYP24A1 in calcium metabolism, we generated a mouse with constitutive kidney-specific deletion of Cyp24a1 (Six2Cre-Cyp24flox). Six2 marks the nephron progenitor population throughout nephrogenesis. We hypothesized that hypercalcemia as seen in CYP24A1 inactivating mutations is related to lack of both renal and extrarenal expression, and that renal deletion does not lead to severe hypercalcemia. To confirm Cyp24a1 deletion, we measured mRNA expression in the kidney using qPCR and RNA in situ hybridization. All mice were fed a standard commercial rodent diet and followed longitudinally for five months with interval calcium measurements. At time of termination, serum PTH levels were measured along with vitamin D-dependent calcium transporters as a functional measure of 1,25(OH)2D3 action. Cyp24a1 expression was significantly knocked down in total kidneys from Six2Cre-Cyp24flox mice as compared to intestinal expression suggesting successful gene deletion. Compared to age-matched wildtype controls, Six2Cre-Cyp24flox mice were mildly but persistently hypercalcemic (diff between means= 0.46 mg/dL, p-value: 0.03, n=8 per group). As expected, 1,25D-dependent calcium transporters in the kidney (Calb1, Trpv5, Slc8a1, Atp2b1) and intestine (Trpv6, s100g) were all increased, consistent with increased systemic 1,25(OH)2D3 activity. PTH levels were appropriately suppressed in the Six2Cre-Cyp24flox mice (diff between means=83 pg/mL, p-value 0.2, n=9 control, n=3 exp) as were renal cyp27b1 mRNA expression. These data suggest that renal CYP24A1 is important for systemic 1,25(OH)2D3 regulation, but the lack of severe hypercalcemia supports critical contributions of extra-renal CYP24A1.
In Vivo Effects of Osteoblast-Specific Overexpression of Gα s and Gα q/11 on Bone Formation and Bone Remodeling During Fracture Healing
Authors: Lee Kathy Kyungeun , Mitchell Jane
Published: May 2021

Although the regenerative potential of bone is high, fracture healing is sometimes compromised resulting in fracture non-union. Successful prevention and treatment of non-union rely on accurate prognosis of fracture and treatment assignment but are often impeded by a high degree of heterogeneity in fracture pathogenesis and treatment response. Burgeoning evidence that indicates differential levels of G proteins among healthy populations offers a plausible explanation, since G protein signaling plays regulatory roles in bone development and remodeling. We previously demonstrated the in vivo effects of G protein level variation on bone development by characterizing the skeletal phenotypes of two transgenic mouse lines that overexpress normal Gα s (Gs-Tg) or Gα 11 (G11-Tg) in osteoblast lineage cells under the control of the 3.6-kb Col1a1 promoter. Gs-Tg mice showed high bone mass but diminished bone quality due to increased formation of woven bone and cortical porosity. Conversely, G11-Tg mice displayed a low bone mass phenotype with reduced bone strength primarily due to increased bone resorption. It still remains unclear, however, how variation in G protein signaling in osteoblasts affects the rate and quality of bone repair. To characterize bone healing in Gs-Tg and G11-Tg mice, we induced a stabilized transverse osteotomy in the tibia of wild-type, Gs-Tg or G11-Tg at 8 weeks of age and assessed the progression of bone healing at the tissue and molecular levels by Micro-CT, histomorphometry, and quantitative gene expression analysis at 1, 2, 3, and 4 weeks post-fracture. The effects of increased G protein signaling during repair on Wnt and Hh signaling, the two signaling pathways essential in osteogenesis, were also examined by assessing mRNA levels of key components of each pathway. Persistent upregulation of Wnt and Hh signaling in Gs-Tg fractures led to enhanced callus mineralization and new woven bone formation at the expense of cartilaginous callus formation and defective bone remodeling. G11-Tg fractures, in contrast, showed minimal changes in Wnt and Hh pathways and consequently led to only subtle changes in the healing response with a transient increase in callus mineralization followed by its rapid resorption. Our results indicate that G protein signaling in osteoblasts regulates bone formation and remodeling during fracture repair in part by tightly controlling the strength and duration of Wnt and Hh signaling pathways.
Modeling COVID 19: The Value of Practice
Authors: Fredericks Robert S
Published: May 2021

The necessity of developing models that effectively organize data for the purpose of translating basic science to clinical care is being increasingly recognized. Reliance upon digital computational methods restricts the value of natural experience reportable by patients, often considered subjective. In the course of modeling phosphate metabolism in the context of clinical practice it has become evident that use of categories based on normality, as definition of health, is inconsistent with the experience of patients. Given the opportunity, patients can provide detailed observations upon their experience of heat as the principle component of metabolism. It seems logical that heat should also be the foundational principal component of models developed for the translation of data to clinical care. This strategy has been applied to modeling the role of ACE2 in the expression of variable phenotypes of COVID 19. Attempts to engage massive data and super-computing to the modeling of COVID 19 supported the assumption that ACE2 is a critical component causing disease. The finding is attributed to an influence, not on heat, but instead suggested bradykinin that has long been a proposed explanation for ACE inhibition on chronic cough. Our modeling would posit that the ACE system engages aldosterone and subsequent influence on heat and acid/base balance as the mediators of variance in the expression of individual phenotypes. This clarification has been useful for addressing complexity in the presentation of metabolic disorders including thyroid disease, Diabetes, bone health, sleep disorders, vascular disease and Chronic Fatigue Syndrome. It appears that the risk of developing ARDS shares a predisposition to chronic kidney disease mediated by excessive FGF23 effects, while the asymptomatic spreaders are more Klotho dependent. The vitamin D system is also complex and involved in the modulation of heat and phosphate. These and other components can be extended to understanding bone and the hematopoietic marrow niche governing immune responses and includes a role for modulation of the microbiome influences by ACE2.

It is concluded that SARS-CoV-2 has helped to clarify the complexity of biology and has exposed the limitations of modeling strategies that do not include the application of case-based practice that can be described as “model-dependent realism” 1 as a means to discover the principle components of nature. The models are the valued product of the research that is mandated by the Helsinki accords when outcomes do not meet expectations. These models can facilitate the organization of all data in the appropriate translation to clinical care.

1 Hawking S., Mlodinow L. The Grand Design p 39–59, Bantom Books NY, 2010
Therapeutic Potentials of Dimeric Cys25PTH(1–34) Peptide for Osteoporosis and Fracture Healing of the Bones- Buy One, Get One Free
Authors: Park Doori , Kitaura Yoshiaki , Dean Thomas , Ohba Shinsuke , Gardella Thomas James , Chung Ung-il , Lee Soo Young , Lee Sihoon
Published: May 2021

Objective: The extraordinarily high bone densities identified in the hypoparathyroidism patients originating from PTH R25C mutation suggested the possibility that this modified protein has unique biologic effects and contributes to the gain of bone volume. Interestingly, western blot of cell lysates stably transfected with PTH R25C construct revealed that Cys25PTH(1–84) formed a dimer, presumably due to disulfide bonding of the cysteine residues. This study aims to study the characteristics of Cys25PTH(1–34) dimeric peptide (Dimer) both in vitro and in vivo for potential therapeutic application of Dimer as a novel anabolic agent. Methods: Identity of the chemically synthesized Dimer was confirmed by its molecular weight and purity using MS and HPLC, respectively. Basic characteristics, for example, ability to bind to PTHR and cAMP production were investigated using a variety of cells. In addition, the ligand-receptor internalization was investigated using TMR tagged Dimer. In vivo characteristics, such as calcemic and phosphatemic responses, pharmacokinetics and pharmacodynamics, were assessed in CD1 mice. The osteoanabolic effects of Dimer were assessed using a fracture-healing model, a calvarial-injection model and an OVX mouse model. Results:In vivo study showed that Dimer has similar calcemic and phosphatemic responses to PTH(1–34; WT). In cell assays, Dimer showed a similar cAMP production but slightly lower binding affinity compared to WT. Dimer-receptor complex was internalized into the cells. Surprisingly, Dimer showed a potent anabolic effect in the fracture-healing model in mice measured as the callus volume fraction by microCT. We also observed a comparable anabolic effect of Dimer in calvarial-injection model and OVX model. Conclusions: Dimeric Cys25PTH(1–84) peptide might play a substantial role in the high bone mass in hypoparathyroidism patients, originating from the PTH R25C mutation. This may be translated into the development of potential therapeutic modality for the treatment of osteoporosis and fracture healing using Dimer.
Efficacy of Low Dose Denosumab in Maintaining Bone Mineral Density in Postmenopausal Women With Osteoporosis Switching From 60mg to 30mg 6 Monthly: A Real World, Prospective Observational Study
Authors: Khan Aliya , Alrob Hajar Abu , Said Hosay , Iqbal Salman , Hweija Ismail , Hussain Sharjil
Published: May 2021

Introduction: Denosumab, a fully human monoclonal antibody to RANK-ligand, has been shown to increase bone mineral density (BMD) and reduce the risk of fracture in postmenopausal women with osteoporosis. Cessation of denosumab is associated with rises in bone remodelling, reductions in BMD and an increased risk of fracture. The primary objective of this study is to evaluate the efficacy of low dose denosumab (30mg/6 months) in preventing bone loss in postmenopausal women with osteoporosis switching from 60mg to 30mg every 6 months. We report the effects of low dose denosumab for upto 2years in patients previously treated with denosumab for >=3 years as well as < 3years. Methods: Following informed consent, postmenopausal women with osteoporosis who had been on denosumab 60mg every 6 months were switched to receive 30mg of denosumab every 6 months.. Patients with an additional skeletal disorder, prior fragility fracture, or on oral steroids (daily in the past 12 months) were excluded. The primary endpoint was the percent change in BMD at the lumbar spine (LS), total hip (HP), femoral neck (FN) and 1/3 radius (1/3R) at 12 and 24 months. Secondary outcomes were adverse effects and fracture Results: 127 patients were included in the study. 44 patients had received 60 mg for 3 years or longer before transitioning to 30mg and 83 patients switched before completing 3 years on full dose therapy. Patients on less than 3yrs of 60mg therapy before the switch showed a significant improvement in BMD at LS (+2.00%, 95% CI 0.49% to 3.51%, n = 55, p-value = 0.01) 1 year post transition. There were no significant changes at the FN, TH or 1/3 radial sites 1 year post transition compared to baseline. At 2 years post transition (n=35) significant changes were noticed at LS (+4.65%, 95% CI 2.29% to 7.01%, p value <0.001), FN (+ 4.87%, 95% CI 1.46% to 8.28%, p value = 0.006) and 1/3 radial sites (+4.95%, 95% CI 0.73% to 9.17%, p value = 0.02). No significant changes were noted at TH. Similar results were seen with prior denosumab therapy for <3years No fractures were observed in this observational study. Conclusions: Switching from 60mg of denosumab to 30 mg every 6 months was not associated with reductions in BMD and may be a valuable treatment option in patients who have completed long term denosumab therapy.
Effect of Statin Use on the Risk of Osteoporotic Fracture in Patients With Metabolic Syndrome: A Nested Case-Control Study
Authors: Kim Kyoung Jin , Choi Jimi , Kim Ji Yoon , Bae Jae Hyun , Kim Kyeong Jin , Kim Hee Young , Yoo Hye Jin , Seo Ji A , Kim Nan Hee , Choi Kyung Mook , Baik Sei Hyun , Kim Sin Gon , Kim Nam Hoon
Published: May 2021

Statins may have advantageous pleiotropic effects on bone metabolism, however, the clinical evidence about the association is still unclear. Although many studies have already evaluated this association, they have performed mostly in a general population with limitation of between-study heterogeneity. Statin may not be equally effective for bone metabolism to every patient, but it can give some benefits for some patients especially with metabolic syndrome (MetS). However, no recent study assessing this relationship, to best our knowledge, has evaluated specifically on patients with MetS. It is also unclear whether the association between statin and osteoporotic fracture differ by statin intensity, dose (cumulative defined daily dose), and duration. This study aimed to investigate the association of statin use with the risk of major osteoporotic fracture in MetS patients from a population-based cohort (NHIS-HEALS, 2002–2015). A nested case-control study was performed in patients with MetS (≥50 years) who had no history of previous osteoporotic fracture. This study included 17,041 cases diagnosed as new-onset osteoporotic fractures and controls matched in a 1:1 ratio by age, sex, body mass index, cohort entry date, and follow-up duration. Conditional logistic regression analysis was used to evaluate covariate-adjusted odds ratio (OR) and 95% confidence interval (CI). During the 4-year follow up period, statin users had a significantly lower risk of major osteoporotic fractures by 9% (OR, 0.91; 95% CI, 0.85 to 0.97) compared with non-users. Among subtypes of major osteoporotic fracture, a risk reduction of vertebral fracture was significant (OR, 0.86; 95% CI, 0.79 to 0.94), but not non-vertebral fracture (OR, 0.97; 95% CI, 0.88 to 1.06) with statin use. Longer duration (OR, 0.97 per 1 year) and cumulative dose (OR, 0.97 per 365 defined daily dose) of statin was negatively associated with the risk of major osteoporotic fracture. There was no difference in risk of major osteoporotic fractures among groups according to statin intensity. In conclusion, this study supports the hypothesis that statin treatment has a beneficial effect on major osteoporotic fracture, especially for vertebral fracture, in patients with MetS with a possibly dose-effect relationship.
Ethnicity, Ethnic Language, and Fracture Risk Conditions in Women Initiating Osteoporosis Therapy
Authors: Lo Joan Chia-Mei , Chandra Malini , Darbinian Jeanne A , Hui Rita L , Gordon Nancy P
Published: May 2021

Introduction: The ethnic diversity of women with osteoporosis has increased, but data on acculturation and health remain limited. Having a primary language (PL) other than English may reflect acculturation level and/or immigration as an adult. We used electronic health record (EHR) data from a large US health plan to examine the association of baseline clinical risk conditions and PL among US Chinese and US Hispanic women who initiated osteoporosis therapy. Methods: We identified women age 65-74y who initiated osteoporosis therapy in 2002–2014, excluding those with skeletal disorders, advanced kidney disease and metastatic cancer. PL was ascertained from the EHR. The study included 1676 Chinese women with English-PL (50%) vs Chinese-PL (50%); 3453 Hispanic women with English-PL (72%) vs Spanish-PL (28%); and 20,289 non-Hispanic White (White) women with English-PL. Clinical conditions assessed included: current smoking; BMI <19 kg/m2; Charlson-Deyo Comorbidity Index (CCI); diabetes (DM) based on diagnosis with treatment; rheumatoid arthritis (RA) based on 2 diagnoses; and fracture diagnosis in the prior 5 years. Language subgroups (* denotes significant difference by PL, p<.05) and ethnic groups (all ethnic differences cited are significant at p<.05) were compared using chi-square tests. Results: Mean age was (69±3y) for Chinese, Hispanics, Whites, and PL subgroups. Prior fracture was lower in Chinese (12.8%) and Hispanics (25.6%) vs Whites (29.7%), with Chinese lower than Hispanics. Smoking was lower in Chinese (1.6%) and Hispanics (6.7%) vs Whites (11.3%). CCI score ≥3 was lower in Chinese (5.2%) and higher in Hispanics (13.0%) vs Whites (10.4%). RA was low overall and lowest in Chinese, especially Chinese-PL. More Chinese (4.2%) and fewer Hispanics (0.8%) had a BMI <19 vs Whites (2.2%). DM was higher in Hispanics (14.8%) and Chinese (8.2%) compared to Whites (5.7%). Significant and non-significant differences by PL were observed for current smoking (0.8%* vs 2.4% for Chinese-PL vs English-PL; 4.0% vs 7.8% for Spanish-PL vs English-PL), prior fracture (11.4%* vs 14.2% for Chinese-PL vs English-PL; 24.3% vs 26.1% for Spanish-PL vs English-PL) and DM (10.5%* vs 5.8% for Chinese-PL vs English-PL; 24.3% vs 26.1% for Spanish-PL vs English-PL) in Chinese and Hispanic women. Conclusion: Among older women initiating osteoporosis therapy, US Chinese women have lower comorbidity but a higher DM prevalence compared to white women, especially those with Chinese-PL. Hispanic women have higher comorbidity and higher DM prevalence than White women, with no differences by PL. Variation in prior fracture, low BMI, RA, and smoking were also seen. These findings highlight ethnic differences in women receiving osteoporosis care, including differences by primary language in Chinese women. Future studies should examine fracture risk factors and outcomes in US immigrant populations, especially Asians.
Impact of Thyroid Disease on Bone Mineral Density Preservation in Patients With Osteoporosis and Idiopathic Hypercalciuria
Authors: Chu James W
Published: May 2021

Background: Idiopathic hypercalciuria (IHC) is associated with reduced bone mineral density (BMD) and increased risk of osteoporotic fractures. It is not known if thyroid disease impacts the degree of urine and bone mineral abnormalities in patients with IHC and osteoporosis (OPO).

Methods: Retrospective chart review from a private endocrinology clinic identified 62 consecutive patients with OPO (fragility fracture and/or t-score ≤-2.5 on bone density scan) and concomitant diagnosis of IHC (urine calcium > 4.0 mg/kg weight/d when intaking low-moderate calcium amounts). Patients were classified into two groups: those with thyroid disease (Thy+, if presence of autoimmune thyroid disease [AITD] with high antibody titers and/or long-term thyroid medication use) and those without (Thy-). Comparisons were made between the two groups for severity of renal disease (urine calcium) and bone disease (number of fragility fractures, and BMD response to therapy).

Results: Of 55 women and 7 men identified with both OPO and IHC, 30 were Thy+ (4 with Graves’, 11 with confirmed Hashimoto’s, 13 taking levothyroxine for presumed Hashimoto’s and 2 with thyroid cancer), and 32 were Thy- (including 2 with type 1 DM, 1 with vitiligo, and 6 with non-toxic nodular goiters requiring biopsies). Thy+ were compared to Thy- with respect to: mean age (70.7 ± 7.3 vs. 70.8 ± 9.3 y), sex (97% vs. 81% women), 24-hr urine calcium at diagnosis (317 ± 75 vs. 311 ± 68 mg), presence of fragility fracture (50% vs. 59%), use of thiazide (83% vs. 78%), and use of anti-fracture pharmacotherapy (73% vs. 84%).

50 patients had adequate comparative longitudinal BMD data. A (+) BMD response was based on consistent increases in BMD and/or t-scores across all spine and hip sites, and a (-) BMD response was classified by decreased BMD and/or t-scores across all sites. For Thy+ vs. Thy- patients, there were 25% vs. 69% (+) BMD response, 38% vs. 12% (-) BMD response, 21% vs. 4% with no significant BMD response, and 17% vs. 15% with mixed BMD responses.

Conclusions: In this group at high risk for future fragility fractures, much lower rates of BMD preservation was seen in the Thy+ as compared to the Thy- patients. Overall, AITD and medical thyroid disease was very common (48%) in this cohort of patients with IHC and OP. However, this high rate may be confounded by the selective nature of the specialty clinic population. Further research needs to delineate the impact of AITD and thyroid medication use on the progression and treatment of patients with IHC and OPO.
Radiofrequency Multi Echographic Spectrometry (REMS) Technology in Patients With Bone Artifacts
Authors: Tomai Pitinca Maria Dea , Caffarelli Carla , Gonnelli Stefano
Published: May 2021

Introduction: Dual-energy X-ray Absorptiometry (DXA) is considered the gold standard examination for the evaluation of bone mineral density (BMD). However, it is known that some conditions, such as arthrosis, vertebral collapse, or vertebroplasty, result in an overestimation of the BMD measured by DXA. Conversely, Radiofrequency Echographic Multi-Spectrometry (REMS) technology is able to automatically discard signals related to bone artifacts, such as calcifications or osteophytes, thanks to the identification of unexpected spectral features (Diez-Perez et al. 2019). The aim of this work is to assess the performance of REMS technology in patients with bone alterations that could alter the densitometric examination. Materials: The bone densitometry exams, both REMS and DXA, of patients with evidences of bone alterations at lumbar vertebrae or femoral neck were analysed. Written patient informed consent was obtained before the scans. Results: Eighty-seven patients with spinal artifacts, including 22 patients with vertebroplasty, 26 patients with bone fracture and 38 patients with osteo-arthrosis were considered. At lumbar spine, the mean BMD and T-score values assessed by REMS was lower than the ones measured by DXA. Moreover, the results obtained by the two technologies were not correlated. On the contrary, the BMD and T-score values measured by REMS and DXA at the femoral site were highly correlated (p<0.01), as well as BMD and the T-score values measured by DXA at the femoral neck and by REMS at the lumbar spine (p<0.01). As concerning artifacts involving femoral site, a patient with an intramedullary gamma nail positioned following a displaced pertrochanteric fracture of the left femur underwent a DXA scan of the right femur and a REMS scan of both femurs. A diagnosis of osteoporosis at the right femur was posed by both technologies. At the left femur with intramedullary gamma nail, REMS only made a diagnosis of osteoporosis highly corresponding with the one performed at right femur. Conclusions: The results from the patient series with spinal artifacts and the clinical case with femoral intramedullary gamma nail show the ability of REMS to evaluate anatomical sites that would not be assessable by DXA, such as in case of implanted nails, or that would give unreliable higher BMD values, such as in case of vertebroplasty, osteo-arthrosis and bone fracture. References: Diez-Perez et al. Aging Clin Exp Res 2019;31(10):1375–89
A Phase 2B, Open-Label, Dose-Ranging Study of Encaleret (CLTX-305) in Autosomal Dominant Hypocalcemia Type 1 (ADH1)
Authors: Gafni Rachel Ilana , Hartley Iris Ruth , Roszko Kelly Lauter , Nemeth Edward F , Pozo Karen A , Sani-Grosso Ramei , Sridhar Ananth , Fox Jonathan C , Collins Michael T
Published: May 2021

Autosomal dominant hypocalcemia type 1 (ADH1) is a rare form of hypoparathyroidism caused by gain-of-function pathogenic variants in the gene encoding the calcium-sensing receptor (CaSR). It is characterized by variable degrees of hypocalcemia, hyperphosphatemia, and hypomagnesemia, with inappropriately low levels of parathyroid hormone (PTH) and hypercalciuria. Conventional therapy includes oral calcium and activated Vitamin D supplementation, which can lead to or exacerbate hypercalciuria. As a result, patients may develop nephrolithiasis and/or nephrocalcinosis, which can progress to renal insufficiency. Calcilytics (antagonists of the CaSR) have demonstrated in in vitro and in vivo models of ADH1, as well as in a small clinical trial (Roberts et al, JBMR 2019), the ability to shift the dose-response relationship between extracellular calcium and the cellular response of cells bearing the mutant CaSR towards normal. This shift has the potential to increase endogenous PTH secretion which in turn may promote skeletal release of calcium into the bloodstream, production of endogenous calcitriol, renal excretion of phosphate, and renal reabsorption of calcium. Additionally, direct effects of calcilytics on renal CaSRs may further reduce renal calcium and magnesium excretion in ADH1. Taken together, this class of drugs has the capacity to restore normal mineral homeostasis, without calcium and activated vitamin D supplements and without attendant risks of iatrogenic hypercalciuria. This Phase 2b, open-label, dose-ranging study will evaluate the safety, tolerability, pharmacodynamics, and pharmacokinetics of the calcilytic encaleret (CLTX-305) in up to 16 participants with ADH1 (NCT04581629). The study will consist of 3 periods. In periods 1 and 2, participants will undergo a 1-week inpatient evaluation to study the safety and tolerability of daily and twice-daily doses of encaleret. Period 3 will follow participants for up to 24 weeks of continuous outpatient dosing, with periodic inpatient and outpatient assessments. The primary endpoint of period 3 is the change from baseline in albumin-corrected blood calcium concentration. Secondary endpoints of the study include the change in urine calcium (fractional and 24-hour excretion), 1,25-dihydroxy-Vitamin D, phosphate, magnesium, and other blood/urine biomarkers. Enrollment for this study at the National Institutes of Health (NIH) began in September 2020 with topline results expected in 2021. This study is supported by Calcilytix Therapeutics, Inc. and the NIH Intramural Research Program.
Circulating MicroRNA-23a-5p Is a Potential Biomarker for Recovery of Bone Mass After Parathyroidectomy in Primary Hyperparathyroidism
Authors: Lee Seunghyun , Hong Namki , Kim Kyoung Jin , Jeong Jong Ju , Rhee Yumie
Published: May 2021

Circulating microRNA (miRNA), a non-coding RNA molecule, is the potential biomarker for bone and mineral metabolism. Primary hyperparathyroidism (PHPT) is one of the leading causes of secondary osteoporosis. After parathyroidectomy, BMD improves as parathyroid hormone (PTH) decreases in patients with PHPT but degree of recovery in BMD vary greatly among patients. Biomarkers which are able to predict postoperative bone response may facilitate individualized approach to PHPT treatment. In this study, we aimed to investigate whether changes of miRNA related to PHPT can predict postoperative BMD recovery. A total 12 patients (10 women) who underwent parathyroidectomy for PHPT at Severance hospital from 2016 to 2019 were analyzed. A total of 15 selected miRNAs (miR-19b-3p, miR-21-5p, miR-23a-3p, miR-152-3p, miR-335-5p, miR-375, miR-532-3p, miR-24-3p, miR-100-5p, miR-125b-5p, miR-24-5p, miR-93-5p, miR-122-5p, miR-124-3p, and miR-148a-3p) from literature review were measured from pre- and pot-operative serum samples. Among pre-, post-operative level, and fold changes [the normalized gene expression(2-ΔCt) in postoperative period divided the normalized gene expression (2-ΔCt) in pre-operative period] of each miRNA, potential predictors of femoral neck BMD changes (%) as primary outcome were selected by univariable regression. The mean age of patients during parathyroidectomy was 56±16 years. PTH level and calcium level restored to normal range after parathyroidectomy in all subjects. (pre to postoperative: PTH, median 113 to 42; calcium, mean 10.6 to 9.2). Circulating level of miR-19b-3p, miR-21-5p, miR-100-5p, miR-125-5p, miR-152-3p and miR-335-5p dropped significantly after parathyroidectomy (p<0.05 for all). A fold change in miR-23a-5p showed a negative correlation with changes (%) in femur neck BMD (β coefficient=-10.58, 95% CI=-19.84 to -1.31, p=0.029). The association remained robust (β coefficient=-7.25, 95% CI=-14.17 to -0.34, p=0.042) even after adjustment for gender, age, and preoperative PTH level in multiple linear regression model. Preoperative miR-124-3p showed a positive correlation with changes in total hip BMD (β coefficient=-9.748, 95% CI= 3.740 to 15.755, p=0.005), but there was no association after adjustment for gender, age, and preoperative PTH level. In conclusion, a fold change in circulating miRNA-23a-5p predict the degree of improvement for femoral neck BMD. MiRNA have potential to serve as novel biomarker to predict treatment response in patients with PHPT, which merits further investigation.
Risk of Chronic Kidney Disease in Adult Patients With Chronic Hypoparathyroidism Treated With rhPTH(1–84) Compared With a Historical Control Cohort
Authors: Gosmanova Elvira , Ayodele Olulade , Sherry Nicole , Mu Fan , Briggs Allie , Swallow Elyse , Rejnmark Lars
Published: May 2021

Patients (pts) with chronic hypoparathyroidism are at increased risk of renal complications. This study evaluated chronic kidney disease (CKD) outcomes over a period of up to 5 years in adult pts with chronic hypoparathyroidism treated with recombinant human parathyroid hormone (1–84), rhPTH(1–84), compared with a historical control cohort of pts who did not receive rhPTH(1–84). The cohort of pts with chronic hypoparathyroidism treated with rhPTH(1–84) was derived from the NCT00732615 (REPLACE), NCT01268098 (RELAY), NCT01297309 (RACE) and NCT01199614 (HEXT) clinical trials. The control cohort of adult pts who did not receive rhPTH(1–84) or rhPTH(1–34) was selected from the US Explorys electronic medical record database (Jan 2007−Aug 2019), using criteria similar to the enrollment criteria used in the trials. Index date was the day after treatment initiation for the rhPTH(1–84) cohort, and the day after the first calcitriol prescription for the control cohort. Pts with CKD at baseline (defined as estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2 at the closest eGFR measurement before the index date) were excluded. All included pts had ≥1 eGFR measurement within 6 months before the index date and ≥2 eGFR measurements ≥3 months apart during the 5 years on or after the index date. The CKD outcome was defined as first occurrence of eGFR <60 mL/min/1.73 m2 confirmed by a second measurement ≥3 months after. Risk of CKD was assessed in a Kaplan-Meier analysis and a Cox proportional hazards model adjusted for demographic characteristics, baseline clinical conditions (including acute manifestations of hypoparathyroidism), and baseline laboratory measurements. The analysis included 118 pts in the rhPTH(1–84) cohort and 478 pts in the control cohort. Pts in the rhPTH(1–84) cohort, compared with pts in the control cohort, were younger (mean ± SD age, 45.3±11.4 vs 51.5±16.2 years; P<0.001), a higher proportion were White (97.5% vs 81.6%; P<0.001), and a lower proportion had acute manifestations of hypoparathyroidism before the index date (15.3% vs 73.2%; P<0.001). In a Kaplan-Meier analysis, rhPTH(1–84)-treated pts had a significantly reduced risk of developing CKD compared with pts in the control cohort, with 11.0% and 27.0% of pts in each cohort, respectively, developing CKD during follow-up (P<0.01). The adjusted hazard ratio of developing CKD associated with rhPTH(1–84) treatment vs no rhPTH(1–84) treatment was 0.47 (95% CI, 0.25−0.88; P<0.05). Pts with chronic hypoparathyroidism treated with rhPTH(1–84) in long-term clinical trials had a significantly reduced risk of developing CKD compared with pts in a control cohort who did not receive rhPTH(1–84). These results should be viewed in light of possible treatment differences in the studied cohorts (ie, predefined trial protocols vs real-word practice for the control cohort).
Body Composition And Bone Mineral Differences According to Lamin A (LMNA) Genotype in Familial Partial Lipodystrophy Type 2
Authors: de Freitas Maria Cristina Foss , Akinci Baris , Corsa Callie , Rothberg Amy E , MacDougald Ormond A , Oral Elif A
Published: May 2021

Phenotypic heterogeneity is well known in Familial Partial Lipodystrophy Type 2 (FPLD2), a rare form of adipose tissue disorder caused by pathogenic mutations in LMNA gene. Animal studies from our group have identified an association between adipose tissue loss and an increase in bone mineral density (BMD) in a mouse model with adipose tissue specific knockout of LMNA gene. Aiming to translate this observation to patients with FPLD2, we analyzed body composition data obtained by dual X-ray absorptiometry from 61 patients diagnosed with FPLD2 and 61 individuals with no diagnosis of FPLD (nFPLD) matched for sex, age and body mass index. As expected, we observed lower total fat mass in FPLD2 patients compared to nFPLD (15.8±9.3 kg vs. 28.5±12.4 kg, p=0.001), as well as lower fat mass in regions of arms, legs and trunk. Interestingly, patients with FPLD2 showed lower bone mineral density (BMD) compared to nFPLD 1.0±0.2 g/cm3 vs 1.2±0.1 g/cm3, p=0.01) and lower t-score (0.2±1.8 vs.1.5±1.2). We then aimed to determine if the patients with FPLD2 displayed differences with respect to genotype. For these analyses, the FPLD2 group was divided according to the pathogenic variant; 42 with mutations on the hot spot codon of the LMNA gene (R482: 50.2 ± 164.8 years, 76% women) and 19 with non-hot spot codon mutations (nR482: 44.8 ± 12.8 years, 78% women). Patients in the R482 group were older when they were first diagnosed with lipodystrophy (39.6 ± 18.6 years vs. 36.5 ± 12.3 years, p=0.05). Also, nR482 group presented with more progeroid characteristics. Patients in n-R482 group also had lower weight compared to R482 and nFPLD groups (64.4±14.4 vs. 73.3±18.5 and 77.6±16.6 kg, p=0.01), as well as lower total fat mass (15.3±5.1 vs. 15.8±9.3 and 25.7±11.4 kg, p=0.01) and fat mass ratio (5.8±1.9 vs. 5.9±3.1 and 9.0±4.1, p= 0.01). Control group bone mass was significantly higher in arms, legs and trunk compared to the R482 and nR482 groups. Moreover, the R482 group had lower bone mass in the legs compared to nR482 (690.5±227.2 vs.703.5±95.3 g, p=0.01), while showing higher trunk bone mass (676.4±266.7 vs. 674.1±79.3, p=0.04), in addition to greater fat mass in the legs (3.3±1.6 vs. 2.6±0.7 kg, p=0.05) and trunk areas (10.3±6.1 vs. 10.0±4.2 kg, p=0.03). There were no differences in total bone mass, BMD, and t-scores, according to genotype. Our data showed more fat preservation in LMNA R482 than nR482, presumably leading to a later lipodystrophy diagnosis. Furthermore, bone mass in different regions may be affected by LMNA genotype; however, more studies are needed to define the bone phenotype and fracture risk in FPLD2 population fully.
Effects of the Rate of Impaired Insulin Secretion on Bone Mineral Density in Type 1 Diabetes
Authors: Suzuki Masaki , Urai Shin , Fukuoka Hidenori , Hirota Yushi , Yamamoto Masaaki , Yamamoto Naoki , Shichi Hiroki , Fujita Yasunori , Kanie Keitaro , Iguchi Genzo , Takahashi Yutaka , Wataru Ogawa
Published: May 2021

Background: Type 1 Diabetes mellitus (T1DM) is a well-known condition associated with low bone mineral density (BMD) and bone fracture, in which one of the risk factor is impaired endogenous insulin secretion. However, the association between the rate of impaired insulin secretory capacity in T1DM and BMD remains to be elucidated. Objective: To clarify the effect of the rate of impaired insulin secretion on BMD in T1DM. Patients and Methods: This a retrospective single-center cross-sectional study, in which consecutive one-hundred seventy Japanese patients with T1DM at Kobe University Hospital were registered. According to the diagnostic criteria of The Japan Diabetes Society, patients were stratified into three subtypes; acute-onset (AO) (n =51, male 25%, 39 ± 15 years), slowly-progressive (SP) (n =37, male 37%, 57 ± 14 years), and fulminant (F) (n =12, male 33%, 51 ± 15 years) mainly by insulin secretory capacity at onset of T1DM. Lumbar spine (LS) and femoral neck (FN) BMD Z-score between three groups were evaluated. Results: The LS BMD is lower in AO than SP (p =0.03), while no differences were observed compared to F (SP/AO/F; 0.38 ± 1.08/-0.25 ± 0.96/-0.35 ± 1.01). The FN BMD also tended to be lower in AO than in SP (p =0.08) and in F (p =1.00) (SP/AO/F;0.03 ± 1.01/-0.44 ± 0.96/-0.35 ± 0.70). To identify the factors associated with decreased BMD, the multivariate regression analysis was performed using AO and SP. The LS BMD was associated with the pathogenic group (p =0.01). Since a negative correlation was seen between durations and CPR both in AO and SP group (p <0.01, p <0.01), we divided these subjects into following 5 groups; 1 to 4, 5 to 9, 10 to 14, 15 to 19, and more than 20 years. In these groups, the CPR was lower in AO than in SP in 1 to 4 years (p <0.01). Intriguingly, LS BMD was started to decline in 5 to 9 years (p =0.03) and was still continued in 10 to 14 years (p =0.01). In FN, BMD was started to decline in 10 to 14 years (p =0.01), suggesting the BMD decline followed by impaired insulin secretion. However, the difference of both BMD and CPR between AO and SP groups were not seen in more than 15 years group, indicating this tangent BMD difference is link to the difference of insulin secretion. Conclusions: This study firstly showed that pathogenic subtypes of T1DM differently affected on BMD. A detailed examination of each disease period showed that BMD continued to decrease as impaired insulin secretion.
The Effect of Vitamin D Supplementation on Severe COVID-19 Outcomes in Patients With Vitamin D Insufficiency
Authors: Levitus Corinne , Chekuri Sweta , Assa Andrei , Mohrmann Laurel , Zindman Alexandra , Tabatabaie Vafa , Toscano Fabrizio , Ahmed Masud , Baron Sarah W
Published: May 2021

Introduction: Coronavirus Disease 2019 (COVID-19) deaths have surpassed one million worldwide with limited treatment modalities, and physicians are relying on alternative methods, such as Vitamin D supplementation, to prevent or halt disease progression without direct evidence. Research has proven that vitamin D supplementation can prevent inflammation based on its role in innate immune response; however, there have been limited studies regarding vitamin D supplementation in COVID-19. We aimed to determine whether vitamin D supplementation in vitamin D insufficient patients was associated with fewer severe COVID-19 outcomes, defined as mechanical ventilation or death. Methods: Retrospective study that analyzed data from all adult patients admitted to our tertiary care center between March 2020 and July 2020 with a positive RT-PCR for SARS CoV-2 and a serum 25-hydroxyvitamin D (25[OH]D) level measured within 90 days prior to the index admission. Patients with 25(OH)D <30 ng/mL were considered vitamin D insufficient and patients ordered for least one weekly dose of ≥1,000 units of ergocalciferol or cholecalciferol were considered supplemented. Supplemented vitamin D insufficient patients were compared to non-supplemented vitamin D insufficient patients in terms of severe COVID-19 disease as defined by mechanical ventilation or death. Results: 129 COVID-19 patients with a vitamin D level <30 ng/mL were identified, with a median vitamin D level of 21.4 ng/mL. A total of 43 patients (33.3%) had severe COVID-19 outcomes. 65 (50.4%) patients with vitamin D insufficiency were supplemented and 64 (49.6%) were not supplemented. Vitamin D supplementation with ≥1,000 units (OR 0.6, 95% CI 0.28 - 1.40; p=0.25), ≥5,000 units (OR 0.5, 95% CI 0.26 - 1.23; p=0.15), or ≥50,000 units (OR 1.0, 95% CI 0.42–2.20, p=0.92) weekly had no statistically significant effect on severe COVID-19 outcomes. The odds of severe COVID-19 outcomes in supplemented patients were non-significantly reduced at lower cutoff values for vitamin D insufficiency (<20 ng/mL and <12 ng/mL) for all supplementation amounts. Conclusion: Vitamin D supplementation in patients with vitamin D insufficiency did not significantly reduce severe COVID-19 outcomes; however, vitamin D supplementation was associated with non-statistically significant reduced odds of severe COVID-19 outcomes at lower cutoff values of vitamin D level. These results demonstrate that Vitamin D supplementation may have a protective effect against severe COVID-19 outcomes in patients with lower baseline levels of vitamin D.
CARF (CDKN2AIP) Regulates Hepatic Lipid Metabolism and Protects Against Development of Non-Alcoholic Fatty Liver Diseases
Authors: Hasan Kamrul M , Parveen Meher , Pena Alondra , Calles Erick Galdamez , Gergis Marvy , Espinoza-Derout Jorge , Sinha-Hikim Amiya , Friedman Theodore C
Published: May 2021

Non-alcoholic fatty liver diseases (NAFLD) is the most common form of liver diseases in the USA with 30–40% of American being affected and about 12% with nonalcoholic steatohepatitis (NASH), a leading cause of end-stage liver diseases. NAFLD has been linked with insulin resistance, type2 diabetes, obesity, and cardiovascular diseases but molecular mechanisms underlying the development of NAFLD and its association with metabolic syndromes are poorly understood. In this study, we explored the role of CARF (collaborator of ARF) also known as CDKN2AIP, a novel gene of ARF-MDM2-p53 pathway in the development of NAFLD. It has been shown that, p53, beyond its tumor suppressor functions, can regulate the cellular glucose and lipid metabolism and its activation has been reported to induce hepatic steatosis in mice. However, as a regulator of p53 pathway, the role of CARF in the lipid metabolism and associated metabolic diseases has not been studied yet. Using high-fat diet (HFD) fed obesity mouse model of NAFLD we found that the expression of CARF along with Sirt1, pAMPK, and pACC was significantly decreased in the HFD induced fatty livers compared to control. Similarly, CARF expression was also down-regulated in palmitate (PA)-treated HepG2 cells, an in vitro model of steatosis. We also observed that shRNA mediated knockdown or lentiviral vector mediated overexpression of CARF induced or reduced the endogenous fat accumulation, respectively, in HepG2 cells, suggesting that CARF expression is negatively regulated in NAFLD. Additionally, we performed RNA seq analysis after CARF silencing in HepG2 cells and demonstrated that silencing of CARF altered the expression of genes regulating hepatic de novo lipogenesis, beta-oxidation, and lipid secretion all of which favor the accumulation of fat in the hepatocytes. Furthermore, genes associated with mitochondrial functions such as the TCA cycle and oxidative phosphorylation were also altered which could play a role in the development of NAFLD. Finally, we demonstrated that AAV mediated hepatic overexpression of CARF in HFD fed mouse model significantly reduced the fat accumulation in the liver as evident by H&E staining of liver sections and intrahepatic triglyceride level. Altogether we conclude that CARF plays a vital role in hepatic lipid metabolism and its downregulation perturbs lipid homeostasis leading to hepatic steatosis and the development of NAFLD.
Carotid Intima Media Thickness in Graves Disease: Comparing Overt Hyperthyroid and Remission State
Authors: Nurjannah Intan , Wisnu Wismandari , Tahapary Dicky L , Wijaya Ika Prasetya
Published: May 2021

Background/Objective: Hyperthyroid has been associated with increased cardiovascular event. Carotidintima media thickness (CIMT) is oftenly measured to evaluate the risk of cardiovascularevent. The aim of this study is to measure CIMT in Graves’ disease and to comparebetween subjects in overt hyperthyroidism and remission state. Methods: Our study was a cross-sectional study performed at the outpatient endocrinologyclinic of Dr. Cipto Mangunkusumo Hospital, a tertiary care hospital in Jakarta, Indonesia. Graves’ disease subjects were recruited, of whom then grouped into overthyperthyroidism (clinical signs and symptoms of hyperthyroidism, low THS, highthyroxine levels, treatment naïve of within 3 months of treatments) and remission state(no clinical signs and symptoms of hyperthyroidism, normal THs and thyroxine levels,without any anti thyroid drugs for at least 6 months). CIMT measurements wereperformed by trained physician on both right and left artery carotid arteries using anultrasound equipped with software that automatically measured the CIMT. We alsomeasured lipid profile, fasting blood glucose, and ECG. Results: We recruited 49 Graves’ disease subjects, of whom 32 and 17 subjects werein overt hyperthyroidism and remission state respectively. Median CIMT in overthyperthyroidism and remission state were 0,473 mm and 0,488 mm respectively, p:0,109. Among clinical and laboratory risk factors, only age which had an independentcorrelation with CIMT in Graves disease. (r: 0,371; p:<0,0001). Discussion: Our is the first study that measured CIMT among subjects with Graves’disease in remission and overt hyperthyroidism state, of which we observed nodifferences. This might be due to the fact that the atherosclerosis risk factors were notdistributed evenly on both group, of which subjects were older in the remission group. Ithas been reported that there are increasing CIMT along with aging (0,003-0,010 mm peryear). Furthermore, in remission state we need to take metabolic and physical changesinto consideration, such as increasing weight as much as 2,5% from prior weight alongwith increasing total cholesterol and LDL-cholesterol which both can affect CIMT levels. Conclusions:

There are no significant differences in CIMT between overt hyperthyroid andremission state in Graves’ disease. Keywords: carotid intima media thickness, Graves’ disease, overt hyperthyroid, remission.