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Open access

Practice patterns for chronic hypoparathyroidism: data from patients and physicians in France

Jean-Philippe Bertocchio, Natalie Grosset, Lionel Groussin, Peter Kamenický, Fabrice Larceneux, Anne Lienhardt-Roussie, Agnès Linglart, Gérard Maruani, Eric Mirallie, François Pattou, Riyad N H Seervai, Coralie Sido, Caroline Silve, Aurélie Vilfaillot, Antoine Tabarin, Marie-Christine Vantyghem, Pascal Houillier, and the investigators of the Épi-Hypo study

Context

Recent guidelines have provided recommendations for the care of patients with chronic hypoparathyroidism. Very little is known about actual physicians’ practices or their adherence to such guidelines.

Objective

To describe the physicians’ practice patterns and their compliance with international guidelines.

Design

The cohort studies included were Épi-Hypo (118 physicians and 107 patients, from September 2016 to December 2019) and ePatients (110 patients, November 2019).

Methods

Internet-based cohorts involving all settings at a nationwide level (France). Participants were (i) physicians treating patients with chronic hypoparathyroidism and patients with chronic hypoparathyroidism either participating in the (ii) Épi-Hypo study (Épi-Hypo 2019 patients), or (iii) Hypoparathyroidism France, the national representative association (ePatients).

Results

The physicians’ specialties were mainly endocrinology (61%), nephrology (28%), family medicine (2.5%), pediatrics (2.5%), rheumatology (2%), or miscellaneous (4%) and 45% were practicing in public universities. The median number of pharmaceutical drug classes prescribed was three per patient. The combination of active vitamin D and calcium salt was given to 59 and 58% of ePatients and Épi-Hypo 2019 patients, respectively. Eighty-five percent of ePatients and 87% of physicians reported monitoring plasma calcium concentrations at a steady state at least twice a year. In 32 and 26% of cases, respectively, ePatients and physicians reported being fully in accordance with international guidelines that recommend targeting symptoms, plasma calcium and phosphate values, and urine calcium excretion.

Conclusions

The care of patients with chronic hypoparathyroidism involves physicians with very different practices, so guidelines should include and target other specialists as well as endocrinologists. Full adherence to the guidelines is low in France.

DOI:
https://doi.org/10.1530/EC-21-0350
Volume 11: Issue 1
Open access

Diagnostic performance of the calcium/phosphate ratio for primary hyperparathyroidism in southwest China

Mengting Yin, Qianhui Liu, Qingzhong Wang, Yong He, Haolan Song, Xin Nie, and Guixing Li

Background

The diagnosis of primary hyperparathyroidism (PHPT) remains a challenge because of increased asymptomatic PHPT or patients with normocalcaemic PHPT (NPHPT). In addition, some primary hospitals in China have no equipment to measure parathyroid hormone (PTH) levels. Therefore, an additional, simple, and inexpensive laboratory biochemical marker is urgently needed. The calcium/phosphate (Ca/P) ratio and chloride/phosphate (Cl/P) ratio have been proposed as suitable tools to diagnose PHPT in Europe; however, the Ca/P ratio has never been tested in China. We aimed to conduct a confirmatory study to explore the diagnostic performance of the Ca/P ratio for PHPT in China.

Methods

From January 2015 to December 2020, a total of 155 patients who underwent parathyroidectomy (143 PHPT patients and 12 NPHPT patients) and 153 controls were enrolled in this single-center , retrospective study. Serum calcium, phosphate, parathyroid hormone, 25-hydroxyvitamin vitamin D (25(OH) vitamin D), chloride, alanine transaminase (ALT), aspartate aminotransaminase (AST), estimated glomerular filtration rate (eGFR), and creatinine levels were recorded for all the study participants. Pairwise comparisons were made between groups, and the diagnostic performance of the Ca/P ratio was determined using receiver-operating characteristic (ROC) analysis.

Results

Patients with PHPT had a higher Ca/P ratio than controls (P < 0.001). A Ca/P ratio above 2.94 with a sensitivity of 95.5% and specificity of 98.7% can distinguish PHPT patients from healthy individuals. This index was positively correlated with the PTH level (r = 0.875, P < 0.001).

Conclusion

The Ca/P ratio is an ideal and inexpensive indicator for diagnosing PHPT in China when using a cut-off value of 2.94.

DOI:
https://doi.org/10.1530/EC-21-0267
Volume 10: Issue 11,
Pages:
1387–1392 (6 total)
Open access

A preliminary transcriptome analysis suggests a transitory effect of vitamin D on mitochondrial function in obese young Finnish subjects

Elisabet Einarsdottir, Minna Pekkinen, Kaarel Krjutškov, Shintaro Katayama, Juha Kere, Outi Mäkitie, and Heli Viljakainen

Objective

The effect of vitamin D at the transcriptome level is poorly understood, and furthermore, it is unclear if it differs between obese and normal-weight subjects. The objective of the study was to explore the transcriptome effects of vitamin D supplementation.

Design and methods

We analysed peripheral blood gene expression using GlobinLock oligonucleotides followed by RNA sequencing in individuals participating in a 12-week randomised double-blinded placebo-controlled vitamin D intervention study. The study involved 18 obese and 18 normal-weight subjects (of which 20 males) with mean (±s.d.) age 20.4 (±2.5) years and BMIs 36 (±10) and 23 (±4) kg/m2, respectively. The supplemental daily vitamin D dose was 50 µg (2000 IU). Data were available at baseline, 6- and 12-week time points and comparisons were performed between the vitamin D and placebo groups separately in obese and normal-weight subjects.

Results

Significant transcriptomic changes were observed at 6 weeks, and only in the obese subjects: 1724 genes were significantly upregulated and 186 genes were downregulated in the vitamin D group compared with placebo. Further analyses showed several enriched gene categories connected to mitochondrial function and metabolism, and the most significantly enriched pathway was related to oxidative phosphorylation (adjusted P value 3.08 × 10−14). Taken together, our data suggest an effect of vitamin D supplementation on mitochondrial function in obese subjects.

Conclusions

Vitamin D supplementation affects gene expression in obese, but not in normal-weight subjects. The altered genes are enriched in pathways related to mitochondrial function. The present study increases the understanding of the effects of vitamin D at the transcriptome level.

DOI:
https://doi.org/10.1530/EC-18-0537
Volume 8: Issue 5,
Pages:
559–570 (12 total)
Open access

100 YEARS OF VITAMIN D: Global differences in vitamin D status and dietary intake: a review of the data

Kevin D Cashman

Background

Internationally, concern has been repeatedly raised about the little notable progress in the collection, analysis and use of population micronutrient status and deficiency data globally. The need for representative status and intake data for vitamin D has been highlighted as a research priority for well over a decade.

Aim and methods

A narrative review which aims to provide a summary and assessment of vitamin D nutritional status data globally. This review divides the world into the Food and Agriculture Organisation’s (FAO) major regions: the Americas, Europe, Oceania, Africa and Asia. Emphasis was placed on published data on the prevalence of serum 25-hydroxyvitamin D (25(OH)D) < 25/30 and <50 nmol/L (reflecting vitamin D deficiency and inadequacy, respectively) as well as vitamin D intake, where possible from nationally representative surveys.

Results

Collating data from the limited number of available representative surveys from individual countries might suggest a relatively low overall prevalence of vitamin D deficiency in South America, Oceania and North America, whereas there is more moderate prevalence in Europe and Asia, and possibly Africa. Overall, the prevalence of serum 25(OH)D < 25/30 and <50 nmol/L ranges from ~5 to 18% and 24 to 49%, respectively, depending on FAO world region. Usual intakes of vitamin D can also vary by FAO world region, but in general, with a few exceptions, there are very high levels of inadequacy of vitamin D intake.

Conclusions

While the burden of vitamin D deficiency and inadequacy varies by world regions and not just by UVB availability, the global burden overall translates into enormous numbers of individuals at risk.

DOI:
https://doi.org/10.1530/EC-21-0282
Volume 11: Issue 1
Open access

Impact of vitamin D and vitamin D receptor TaqI polymorphism in primary human myoblasts

Amarjit Saini, Linda Björkhem-Bergman, Johan Boström, Mats Lilja, Michael Melin, Karl Olsson, Lena Ekström, Peter Bergman, Mikael Altun, Eric Rullman, and Thomas Gustafsson

The CC genotype of the vitamin D receptor (VDR) polymorphism TaqI rs731236 has previously been associated with a higher risk of developing myopathy compared to TT carriers. However, the mechanistic role of this polymorphism in skeletal muscle is not well defined. The effects of vitamin D on patients genotyped for the VDR polymorphism TaqI rs731236, comparing CC and TT carriers were evaluated. Primary human myoblasts isolated from 4 CC carriers were compared with myoblasts isolated from four TT carriers and treated with vitamin D in vitro. A dose-dependent inhibitory effect on myoblast proliferation and differentiation was observed concurrent with modifications of key myogenic regulatory factors. RNA sequencing revealed a vitamin D dose–response gene signature enriched with a higher number of VDR-responsive elements (VDREs) per gene. Interestingly, the greater the expression of muscle differentiation markers in myoblasts, the more pronounced was the vitamin D-mediated response to suppress genes associated with myogenic fusion and myotube formation. This novel finding provides a mechanistic explanation to the inconsistency regarding previous reports of the role of vitamin D in myoblast differentiation. No effects in myoblast proliferation, differentiation or gene expression were related to CC vs TT carriers. Our findings suggest that the VDR polymorphism TaqI rs731236 comparing CC vs TT carriers did not influence the effects of vitamin D on primary human myoblasts and that vitamin D inhibits myoblast proliferation and differentiation through key regulators of cell cycle progression. Future studies need to employ strategies to identify the primary responses of vitamin D that drive the cellular response towards quiescence.

DOI:
https://doi.org/10.1530/EC-19-0194
Volume 8: Issue 7,
Pages:
1070–1081 (12 total)
Open access

100 YEARS OF VITAMIN D: Effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis

Jennifer K Y Ko, Jinghua Shi, Raymond H W Li, William S B Yeung, and Ernest H Y Ng

Objective

Vitamin D receptors are present in the female reproductive tract. Studies on the association between serum vitamin D level and pregnancy rate of in vitro fertilization (IVF) showed inconsistent results and focused on a single fresh or frozen embryo transfer cycle. The objective of our study was to evaluate if serum vitamin D level before ovarian stimulation was associated with the cumulative live birth rate (CLBR) of the first IVF cycle.

Design

Retrospective cohort study.

Methods

Women who underwent the first IVF cycle from 2012 to 2016 at a university-affiliated reproductive medicine center were included. Archived serum samples taken before ovarian stimulation were analyzed for 25(OH)D levels using liquid chromatography-mass spectrometry.

Results

In total, 1113 had pregnancy outcome from the completed IVF cycle. The median age (25th–75th percentile) of the women was 36 (34–38) years and serum 25(OH)D level was 53.4 (41.9–66.6) nmol/L. The prevalence of vitamin D deficiency (less than 50 nmol/L) was 42.2%. The CLBR in the vitamin D-deficient group was significantly lower compared to the non-deficient group (43.9%, 208/474 vs 50.9%, 325/639, P  = 0.021, unadjusted), and after controlling for women’s age, BMI, antral follicle count, type and duration of infertility. There were no differences in the clinical/ongoing pregnancy rate, live birth rate and miscarriage rate in the fresh cycle between the vitamin D deficient and non-deficient groups.

Conclusions

Vitamin D deficiency was prevalent in infertile women in subtropical Hong Kong. The CLBR of the first IVF cycle in the vitamin D-deficient group was significantly lower compared to the non-deficient group.

DOI:
https://doi.org/10.1530/EC-21-0444
Volume 11: Issue 2
Open access

Effect of vitamin D supplementation on health status in non-vitamin D deficient people with type 2 diabetes mellitus

S Westra, Y H M Krul-Poel, H J van Wijland, M M ter Wee, F Stam, P Lips, F Pouwer, and S Simsek

Objective

Increased levels of depressive symptoms, fatigue or pain (all dimensions of reduced health-related quality of life (HRQOL)) are common in people with type 2 diabetes mellitus (DM). Earlier studies have reported associations between low vitamin D status and fatigue and depressive symptoms. The aim of the present study was to examine the effects of vitamin D supplementation on dimensions of HRQOL in people with type 2 DM.

Design

Randomised, double-blind, placebo-controlled trial.

Methods

The effect of monthly cholecalciferol 50,000 IU vs placebo on HRQOL was assessed in 275 adults with type 2 DM derived from general practices. HRQOL at baseline and after six months using the Short Form 36 Health Survey (SF-36) was collected. Linear regression analyses were used to compare the change in HRQOL over time between the vitamin D and placebo group.

Results

187/275 (68%) completed baseline and follow-up SF-36 and were included in the analysis. Median serum 25-hydroxyvitamin D almost doubled in the intervention group compared to that in the placebo group (58.5–106.0 nmol/L vs 60.0–61.5 nmol/L, respectively). A small significant difference (adjusted B: −8.90; 95% CI: −17.16 to −0.65) between both groups was seen concerning the SF-36 domain role limitations due to physical problems in disadvantage of the vitamin D group.

Conclusions

Six months of vitamin D supplementation did not improve HRQOL in non-vitamin D-deficient people with type 2 DM managed on oral antidiabetic therapy.

DOI:
https://doi.org/10.1530/EC-16-0070
Volume 5: Issue 6,
Pages:
61–69 (9 total)
Open access

Outcomes of orthopedic surgery in a cohort of 49 patients with X-linked hypophosphatemic rickets (XLHR)

A Gizard, A Rothenbuhler, Z Pejin, G Finidori, C Glorion, B de Billy, A Linglart, and P Wicart

Background

X-linked hypophosphatemic rickets (XLHR) is due to mutations in PHEX leading to unregulated production of FGF23 and hypophosphatemia. XLHR is characterized by leg bowing of variable severity. Phosphate supplements and oral vitamin analogs, partially or, in some cases, fully restore the limb straightness. Surgery is the alternative for severe or residual limb deformities.

Objective

To retrospectively assess the results of surgical limb correction in XLHR (osteotomies and bone alignment except for 3 transient hemiepiphysiodesis).

Methods

We analyzed the incidence of recurrence and post-surgical complications in 49 XLHR patients (29F, 20M) (mean age at diagnosis 6.0 years (± 7.1)).

Results

At first surgery, the mean age was 13.4 years (± 5.0). Recurrence was observed in 14/49 (29%) patients. The number of additional operations significantly decreased with age (2.0 (± 0.9), 1.7 (± 1.0) and 1.2 (± 0.4) in children <11 years, between 11 and 15, and >15 years; P < 0.001). Incidence of recurrence seemed to be lower in patients with good metabolic control of the rickets (25% vs 33%). Complications were observed in 57% of patients.

Conclusion

We report a large series of surgical procedures in XLHR. Our results confirm that phosphate supplements and vitamin D analog therapy is the first line of treatment to correct leg bowing. Surgery before puberty is associated with a high risk of recurrence of the limb deformity. Such procedures should only be recommended, following multidisciplinary discussions, in patients with severe distortion leading to mechanical joint and ligament complications, or for residual deformities once growth plates have fused.

DOI:
https://doi.org/10.1530/EC-17-0154
Volume 6: Issue 8,
Pages:
566–573 (8 total)
Open access

The variation in free 25-hydroxy vitamin D and vitamin D-binding protein with season and vitamin D status

Göran Oleröd, Lillemor Mattsson Hultén, Ola Hammarsten, and Eva Klingberg

Purpose

Serum 25-hydroxy vitamin D [25(OH)D] varies greatly with season at northern latitudes. The purpose of this study was to determine if the seasonal variations in serum total 25(OH)D are followed by a concomitant variation in free 25(OH)D or if the variation is damped by alterations in the binding capacity of DBP.

Methods

Serum was collected from 540 healthy blood donors (60% men; mean age 41 ± 13 years) during 12 months and analyzed for total 25(OH)D, directly measured free 25(OH)D, vitamin D-binding protein (DBP) and albumin. Calculated free 25(OH)D was estimated.

Results

The UV-B radiation during the sampling month was positively correlated with the serum levels of total 25(OH)D (r = 0.355, P < 0.001), directly measured free (r = 0.336, P < 0.001) and calculated free 25(OH)D (r = 0.275, P < 0.001), but not with DBP and albumin. The percentage of free 25(OH)D was higher during the winter months than that during the summer months (0.020 ± 0.005% vs 0.019 ± 0.004%; P = 0.007) and higher in participants with a serum 25(OH)D below 25 nmol/L than that in participants with a serum 25(OH)D above 75 nmol/L (0.031 ± 0.007% vs 0.017 ± 0.003%; P < 0.001). iPTH was correlated with directly measured free 25(OH)D (r = −0.226; P < 0.001), but only weakly with calculated free 25(OH)D (r = −0.095; P = 0.027).

Conclusions

Directly measured free serum 25(OH)D was highly correlated with total serum 25(OH)D and followed the same seasonal variation, whereas the serum concentrations of DBP and albumin were stable. The fluctuation in free 25(OH)D was only marginally damped with an increase in the percentage of free 25(OH)D during the winter months and in participants with vitamin D deficiency.

DOI:
https://doi.org/10.1530/EC-16-0078
Volume 6: Issue 2,
Pages:
111–120 (10 total)
Open access

Vitamin D stimulates multiple microRNAs to inhibit CRH and other pro-labor genes in human placenta

Bingbing Wang, Mayra Cruz Ithier, Nataliya Parobchak, Stacy M Yadava, Jay Schulkin, and Todd Rosen

Maternal vitamin D deficiency is linked to adverse pregnancy outcomes including spontaneous preterm birth (SPB). Placental corticotropin-releasing hormone (CRH) has been proposed to be part of a clock that governs the length of gestation in humans, with elevated maternal serum levels predicting early delivery. In this study, we test the hypothesis that vitamin D could contribute to the prevention of preterm labor by inhibiting CRH and other pro-labor mediators. The biological activity of vitamin D occurs via two pathways: non-genomic and genomic responses, both of which involve binding of 1,25-dihydroxyvitamin D (1,25(OH)2D), the active metabolite of vitamin D binding to the vitamin D receptor (VDR). By using chromatin immunoprecipitation followed by sequencing (ChIP-seq), we found that 1,25(OH)2D stimulates association of VDR with a number of miRNA genes including MIR181B2 and MIR26B, and their mature products miR-181b-5p and miR-26b-5p are predicted to target CRH and cyclooxygenase-2 (COX-2) mRNA at 3′-untranslated region (UTR), respectively. We performed RT-qPCR analysis to validate that expression of mature miR-181b-5p and miR-26b-5p in term human syncytiotrophoblast increased in response to treatment with 1,25(OH)2D. miR-181b-5p- or miR-26b-5p-mediated inhibition of CRH or COX-2 was further assessed by the use of miRNA mimics/inhibitors and a luciferase reporter assay. Taken together, this study has identified novel mechanisms by which vitamin D downregulates pro-labor genes and could lower the risk of preterm delivery.

DOI:
https://doi.org/10.1530/EC-18-0345
Volume 7: Issue 12,
Pages:
1380–1388 (9 total)