Vitamin D deficiency and seasonal variation over the years in São Paulo,Brazil

Summary

Brazil is a tropical/subtropical geographic area with elevated ultraviolet (UV) radiation. We report very high prevalence of vitamin D deficiency in a large database of Brazilian subjects and show seasonal and reciprocal relationship between vitamin D and parathyroid hormone (PTH) over the years in this tropical area.

Introduction

We aim to examine the prevalence of vitamin D deficiency, characterize the temporal relationship between 25-hydroxyvitamin D levels (25(OH)D) and intact PTH (iPTH) according to seasons, and investigate potential associations between 25(OH)D levels and extra-skeletal outcomes in a Brazilian population.

Methods

We retrospectively determined population weekly mean concentrations of unpaired 25(OH)D and iPTH using 39,004 laboratory results of Brazilian individuals of both genders aged 2 to 95 years. The 25(OH)D and iPTH distributions were normalized, and the means fit with a sinusoidal function. Potential associations between 25(OH)D serum levels and inflammatory markers, fasting glucose, HbA1c and Homeostasis Model Assessment index (HOMA) were examined.

Results

Of the samples, 33.9 % had 25(OH)D serum concentrations lower than 20 ng/mL, while the vast majority (70.7 %) were found to be vitamin D deficient or insufficient (<30 ng/mL). Vitamin D deficiency was significantly higher during the winter as compared to the summer (38.4 % <20 ng/mL and 75.5 % <30 ng/mL versus 23.3 % <20 ng/mL and 62.5 % <30 ng/mL, respectively; p?<?0.001). Seasonal variation was observed for both 25(OH)D and iPTH. 25(OH)D peaks occurred in March and troughs in September. iPTH levels showed an inverted pattern of peaks and troughs with a delay of 1?±?5 week. 25(OH)D was significantly associated with inflammatory markers but not with glucose homeostasis.

Conclusions

A sinusoidal interrelationship has been detected between vitamin D and PTH in this tropical population. A large percentage of the individuals showed vitamin D deficiency. Public health strategies are needed to better understand and manage this very high and apparently contradictory prevalence of vitamin D deficiency.

     

Vitamin D in incident nephrotic syndrome: a Midwest Pediatric Nephrology Consortium study

Background

Cross-sectional studies of children with prevalent nephrotic syndrome (NS) have shown 25-vitamin D (25(OH)D) deficiency rates of 20–100 %. Information on 25(OH)D status in incident patients or following remission is limited. This study aimed to assess 25(OH)D status of incident idiopathic NS children at presentation and longitudinally with short-term observation.

Methods

Multicenter longitudinal study of children (2–18 years old) from 14 centers across the Midwest Pediatric Nephrology Consortium with incident idiopathic NS. 25(OH)D levels were assessed at diagnosis and 3 months later.

Results

Sixty-one children, median age 5 (3, 11) years, completed baseline visit and 51 completed second visit labs. All 61 (100 %) had 25(OH)D?<?20 ng/ml at diagnosis. Twenty-seven (53 %) had 25(OH)D?<?20 ng/ml at follow-up. Fourteen (28 %) children were steroid resistant. Univariate analysis showed that children prescribed vitamin D supplements were less likely to have 25(OH)D deficiency at follow-up (OR 0.2, 95 % CI 0.04, 0.6). Steroid response, age, and season did not predict 25(OH)D deficiency. Multivariable linear regression modeling showed higher 25(OH)D levels at follow-up by 13.2 ng/ml (SE 4.6, p?<?0.01) in children supplemented with vitamin D.

Conclusions

In this incident idiopathic NS cohort, all children at diagnosis had 25(OH)D deficiency and the majority continued to have a deficiency at 2–4 months. Supplemental vitamin D decreased the odds of 25(OH)D deficiency at follow-up, supporting a role for supplementation in incident NS.

     

Serum 25-hydroxyvitamin D,parathyroid hormone,calcium intake,and bone mineral density in Spanish adults

Summary

Vitamin D insufficiency is very common among Spanish community-dwelling adult subjects. A threshold of serum 25(OH)D around 30 ng/ml would be necessary for the prevention of secondary hyperparathyroidism and hip bone loss in our population, regardless of the dairy calcium ingestion.

Introduction

This study aims to assess 25-hydroxyvitamin D—25(OH)D—status in Spanish adult subjects and to analyze its relationships with serum PTH levels, calcium intake, and bone mineral density (BMD).

Methods

A total of 1811 individuals (1154 postmenopausal women and 657 men) aged 44–93 years participated in the study. Serum 25(OH)D, intact parathyroid hormone (PTH), aminoterminal propeptide of type I collagen (P1NP), and C-terminal telopeptide of type I collagen (β-CTX) levels were measured by electrochemiluminescence. BMD was determined by dual x-ray absorptiometry (DXA) at lumbar spine, femoral neck, and total hip.

Results

Serum 25(OH)D levels were below 10, 20, and 30 ng/ml in 5, 40, and 83 % of participants, respectively. There was a significant seasonal difference in mean serum 25(OH)D, with higher levels in summer–autumn. In multivariate analysis, 25(OH)D levels were negatively correlated with age, serum PTH and creatinine, body mass index, smoking, alcohol intake, and a number of chronic diseases, but positively with dairy calcium intake. The magnitude of the difference in serum PTH according to 25(OH)D quartiles was not influenced by calcium intake. A threshold of serum 25(OH)D around 30 ng/ml was observed for serum PTH and hip BMD.

Conclusions

Vitamin D insufficiency is very common among Spanish community-dwelling adult subjects. A threshold of serum 25(OH)D around 30 ng/ml would be necessary for the prevention of secondary hyperparathyroidism and hip bone loss in our population, regardless of the dairy calcium ingestion. Programs to improve vitamin D status may be required in our country.

     

Low serum 25-hydroxyvitamin D is associated with increased risk of stress fracture during Royal Marine recruit training

Summary

The aim of this study was to investigate vitamin D status and stress fracture risk during Royal Marine military training. Poor vitamin D status was associated with an increased risk of stress fracture. Vitamin D supplementation may help to reduce stress fracture risk in male military recruits with low vitamin D status.

Introduction

Stress fracture is a common overuse injury in military recruits, including Royal Marine (RM) training in the UK. RM training is recognised as one of the most arduous basic training programmes in the world. Associations have been reported between serum 25-hydroxyvitamin D (25(OH)D) and risk of stress fracture, but the threshold of 25(OH)D for this effect remains unclear. We aimed to determine if serum 25(OH)D concentrations were associated with stress fracture risk during RM training.

Methods

We prospectively followed 1082 RM recruits (males aged 16–32 years) through the 32-week RM training programme. Troops started training between September and July. Height, body weight and aerobic fitness were assessed at week 1. Venous blood samples were drawn at weeks 1, 15 and 32. Serum samples were analysed for 25(OH)D and parathyroid hormone (PTH).

Results

Seventy-eight recruits (7.2 %) suffered a total of 92 stress fractures. Recruits with a baseline serum 25(OH)D concentration below 50 nmol L^?1 had a higher incidence of stress fracture than recruits with 25(OH)D concentration above this threshold (χ² ₍₁₎?=?3.564, p?=?0.042; odds ratio 1.6 (95 % confidence interval (CI) 1.0–2.6)). Baseline serum 25(OH)D varied from 47.0?±?23.7 nmol L^?1 in February, to 97.3?±?24.6 nmol L^?1 in July (overall mean 69.2?±?29.2 nmol L^?1, n?=?1016). There were weak inverse correlations between serum 25(OH)D and PTH concentrations at week 15 (r?=??0.209, p?<?0.001) and week 32 (r?=??0.214, p?<?0.001), but not at baseline.

Conclusion

Baseline serum 25(OH)D concentration below 50 nmol L^?1 was associated with an increased risk of stress fracture. Further studies into the effects of vitamin D supplementation on stress fracture risk are certainly warranted.

     

Prevalence and correlates of 25-hydroxyvitamin D deficiency in the Chronic Kidney Disease in Children (CKiD) cohort

Background

Vitamin D plays an important role in the mineral and bone disorder seen in chronic kidney disease (CKD). Deficiency of 25-hydroxyvitamin D (25OHD) is highly prevalent in the adult CKD population.

Methods

The prevalence and determinants of 25OHD deficiency (defined as a level <20 ng/ml) were examined longitudinally in 506 children in the CKiD cohort. Predictors of secondary hyperparathyroidism and the determinants of 1,25-dihydroxyvitamin D (1,25(OH)₂D) levels were also evaluated.

Results

Deficiency of 25OHD was observed in 28 % of the cohort at enrollment. Significant predictors of 25OHD deficiency were older age, non-white race, higher body mass index, assessment during winter, less often than daily milk intake, non-use of nutritional vitamin D supplement and proteinuria. Lower values of glomerular filtration rate (GFR), serum 25OHD, calcium and higher levels of FGF23 were significant determinants of secondary hyperparathyroidism. Lower GFR, low serum 25OHD, nephrotic-range proteinuria, and high FGF23 levels were significant determinants of serum 1,25(OH)₂ D levels.

Conclusions

Deficiency of 25OHD is prevalent in children with CKD and is associated with potentially modifiable risk factors such as milk intake, nutritional vitamin D supplement use, and proteinuria. 25OHD deficiency is a risk factor for secondary hyperparathyroidism and decreased serum 1,25(OH)₂D in children with CKD.

     

Serum 25-Hydroxyvitamin D in Obese Spanish Adults: the Camargo Cohort Study

Objectives

To describe the 25(OH)D status in Spanish obese postmenopausal women and men ≥?50 years, to compare their results with those of the overweight or normal weight population, and to determine whether differences are observed between both sexes and with seasonal variation throughout the year.

Patients and Methods

We studied 2597 subjects (1826 postmenopausal women and 771 men ≥?50 years). Serum concentrations of 25(OH)D, intact parathyroid hormone (PTH), aminoterminal propeptide of type I collagen (PINP), and C-terminal telopeptide of type I collagen (CTX) were determined by electrochemiluminiscence (Elecsys 2010, Roche). Bone mineral density (BMD) was measured by DXA. Participants were divided according to body mass index (BMI) groups (normal ≥?20 and <?25 kg/m², overweight ≥?25 and?<?30 kg/m², or obese ≥?30 kg/m²).

Results

Obese people had lower serum 25(OH)D values (20.9?±?8.2 ng/ml) than overweight (23.3?±?8.8 ng/ml; p?<?0.0001) or normal-weight subjects (24.4?±?8.9 ng/ml; p?<?0.0001). They have also lower levels of both PINP and CTX. In contrast, PTH concentrations and BDM values were higher in obese individuals. When stratifying by sex, the difference in serum concentration of 25(OH)D remained significant in women, but not in men, persisted throughout the year, and was inversely correlated with BMI and waist circumference.

Conclusions

Despite lower serum 25(OH)D concentrations and higher PTH levels, obese and overweight women have higher lumbar spine and hip BMD and lower bone remodeling markers than normal weight women, suggesting that low serum 25(OH)D levels do not negatively affect bone health.

     

Associations of total and free 25OHD and 1,25(OH)<Subscript>2</Subscript>D with serum markers of inflammation in older men

Summary

Vitamin D is hypothesized to suppress inflammation. We tested total and free vitamin D metabolites and their association with inflammatory markers. Interleukin-6 levels were lower with higher 25-hydroxyvitamin D. 1,25-dihydroxyvitamin D and free 25OHD associations mirrored those of 25OHD. However, associations for the two metabolites diverged for tumor necrosis factor alpha (TNF-α) soluble receptors.

Introduction

Vitamin D is hypothesized to suppress inflammation, and circulating 25-hydroxyvitamin D (25OHD) and inflammatory markers are inversely correlated. However, total serum 25OHD may not be the best indicator of biologically active vitamin D.

Methods

We tested serum total 25OHD, total 1,25(OH)₂D, vitamin D binding protein (DBP), and estimated free 25OHD and free 1,25(OH)₂D associations with inflammatory markers serum interleukin-6 (IL-6), TNF-α and their soluble receptors, interleukin-10 (IL-10), and C-reactive protein (CRP) as continuous outcomes and the presence of ≥2 inflammatory markers in the highest quartile as a dichotomous outcome, in a random subcohort of 679 men in the Osteoporotic Fractures in Men (MrOS) study.

Results

IL-6 was lower in men with higher 25OHD (?0.23 μg/mL per standard deviation (SD) increase in 25OHD, 95 % confidence intervals (CI) ?0.07 to ?0.38 μg/mL) and with higher 1,25(OH)₂D (?0.20 μg/mL, 95 % CI ?0.0004 to ?0.39 μg/mL); free D associations were slightly stronger. 25OHD and DBP, but not 1,25(OH)₂D, were independently associated with IL-6. TNF-α soluble receptors were inversely associated with 1,25(OH)₂D but positively associated with 25OHD, and each had independent effects. The strongest association with ≥2 inflammatory markers in the highest quartile was for free 1,25(OH)₂D (odds ratios (OR) 0.70, 95 % CI 0.54 to 0.89 per SD increase in free 1,25(OH)₂D).

Conclusions

Associations of 1,25(OH)₂D and free 25OHD with IL-6 mirrored those of 25OHD, suggesting that 1,25(OH)₂D and free D do not improve upon 25OHD in population-based IL-6 studies. However, associations for the two metabolites diverged for TNF-α soluble receptor, warranting examination of both metabolites in studies of TNF-α and its antagonists.

     

Vitamin D supplementation improves endothelial dysfunction in patients with non-dialysis chronic kidney disease

Purpose

Hypovitaminosis D is common in chronic kidney disease (CKD) and is associated with endothelial dysfunction and cardiovascular events. This study aimed to investigate the effects of vitamin D supplementation on endothelial dysfunction in non-dialysis CKD patients.

Materials and methods

Seventy-one non-dialysis CKD patients with low vitamin D (serum 25(OH)D < 30 ng/mL) were recruited. Patients received oral cholecalciferol 50,000 units once a week for 12 weeks. Changes in endothelial function by brachial artery flow-mediated dilation (FMD), soluble vascular cell adhesion molecule-1 (sVCAM-1), and sE-selectin were studied.

Results

There was a significant increase in serum levels of 25(OH)D after cholecalciferol supplementation (33.7 ± 12.1 vs. 13.2 ± 5.4 ng/mL, P < 0.001). Multivariable regression analysis showed that higher proteinuria (β = ? 0.548, P < 0.001) and lower levels of 25(OH)D (β = 0.360, P < 0.001) at baseline were related to lower 25(OH)D level after supplementation. FMD increased significantly from 4.4 ± 1.3 to 5.1 ± 1.5% (P < 0.001), and soluble endothelial biomarkers decreased: sVCAM-1 from 926.9 ± 158.0 to 867.0 ± 129.0 ng/mL (P < 0.001), and sE-selectin 69.7 ± 15.8 to 63.3 ± 14.7 ng/mL (P < 0.001).

Conclusions

Vitamin D supplementation can improve endothelial dysfunction in pre-dialysis CKD patients.

     

Prevalence of vitamin D insufficiency among adolescents and its correlation with bone parameters using high-resolution peripheral quantitative computed tomography

Summary

Vitamin D deficiency and insufficiency are highly prevalent among adolescents in Hong Kong, which is a sub-tropical city with ample sunshine. Vitamin D level is significantly correlated with key bone density and bone quality parameters. Further interventional studies are warranted to define the role of vitamin D supplementation for improvement of bone health among adolescents.

Introduction

The relationship between bone quality parameters and vitamin D (Vit-D) status remains undefined among adolescents. The aims of this study were to evaluate Vit-D status and its association with both bone density and bone quality parameters among adolescents.

Methods

Three hundred thirty-three girls and 230 boys (12–16 years old) with normal health were recruited in summer and winter separately from local schools. Serum 25(OH) Vit-D level, bone density and quality parameters by Dual Energy X-ray Absorptiometry (DXA) and High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT), dietary calcium intake, and physical activity level were assessed.

Results

Sixty-four point seven percent and 11.4 % of subjects were insufficient [25?≤?25(OH)Vit-D?≤?50 nmol/L] and deficient [25(OH)Vit-D?<?25 nmol/L] in Vit-D, respectively. The mean level of serum 25(OH)Vit-D in summer was significantly higher than that in winter (44.7?±?13.6 and 35.9?±?12.6 nmol/L, respectively) without obvious gender difference. In girls, areal bone mineral density (aBMD) and bone mineral content (BMC) of bilateral femoral necks, cortical area, cortical thickness, total volumetric bone mineral density (vBMD), and trabecular thickness were significantly correlated with 25(OH)Vit-D levels. In boys, aBMD of bilateral femoral necks, BMC of the dominant femoral neck, cortical area, cortical thickness, total vBMD, trabecular vBMD, BV/TV, and trabecular separation were significantly correlated with 25(OH)Vit-D levels.

Conclusion

Vit-D insufficiency was highly prevalent among adolescents in Hong Kong with significant correlation between Vit-D levels and key bone density and bone quality parameters being detected in this study. Given that this is a cross-sectional study and causality relationship cannot be inferred, further interventional studies investigating the role of Vit-D supplementation on improving bone health among adolescents are warranted.

     

Association of 25-hydroxyvitamin D with areal and volumetric measures of bone mineral density and parathyroid hormone: impact of vitamin D-binding protein and its assays

Summary

A comparison of the association of different forms of 25-hydroxyvitamin D [25(OH)D] with parathyroid hormone (PTH) and with areal and volumetric bone mineral density (BMD) demonstrated that bioavailable and free 25(OH)D do not provide a better index of vitamin D status in terms of bone health compared to total 25(OH)D.

Introduction

This study aims to compare measures of vitamin D-binding protein (DBP) using a monoclonal versus polyclonal ELISA and assess correlations of total versus estimated free and bioavailable 25(OH)D with BMD and PTH concentrations.

Methods

DXA and peripheral quantitative CT (pQCT) scans were obtained in 304 adults (158 black, 146 white), ages 21–80 years. Free and bioavailable 25(OH)D were calculated from total 25(OH)D, DBP, and albumin concentrations. Multivariable linear regression with standardized beta coefficients was used to evaluate associations of bone measures and PTH with total, free, and bioavailable 25(OH)D.

Results

Measures of DBP obtained using a monoclonal versus polyclonal ELISA were not correlated (r _s?=?0.02, p?=?0.76). Free and bioavailable 25(OH)D based on the polyclonal assay were lower in black versus white participants (p?<?0.0001); this race difference was not evident using the monoclonal assay. Adjusted for age, sex, calcium intake, and race, all forms of 25(OH)D were negatively associated with PTH, but the absolute coefficient was greatest for total 25(OH)D (?0.34, p?<?0.001) versus free/bioavailable 25(OH)D (?0.18/?0.24 depending on DBP assay, p?≤?0.003). In analyses stratified on race, none of the measures of 25(OH)D were associated with BMD across DXA and pQCT sites.

Conclusions

The monoclonal versus polyclonal ELISA yielded highly discrepant measures of DBP, particularly among black individuals, likely related to established race differences in DBP polymorphisms. Contrary to prior studies, our findings indicate that using DBP to estimate bioavailable and free 25(OH)D does not provide a better index of vitamin D status in terms of bone health.

     

The vitamin D status in ankylosing spondylitis in relation to intestinal inflammation,disease activity,and bone health: a cross-sectional study

Summary

We assessed the vitamin D status in ankylosing spondylitis (AS) patients and healthy controls in the late winter when no vitamin D is produced by the sunlight. The vitamin D status was often poor, but not lower in AS and not associated with disease activity or signs of gut inflammation.

Introduction

The aims of the study were to investigate the vitamin D levels attained mainly by dietary intake in ankylosing spondylitis (AS) in comparison with healthy controls and in relation to gut inflammation, measured indirectly by fecal calprotectin, disease activity, osteoproliferation, bone mineral density (BMD), and vertebral fractures.

Methods

Serum 25-hydroxy vitamin D (25(OH)D) was measured in 203 AS patients and 120 healthy controls at the end of “the vitamin D winter,” when the out-door UVB irradiation is too low to allow synthesis of vitamin D₃ in the skin at the latitude of Gothenburg, Sweden. Fecal calprotectin was measured in stool samples. Disease activity was assessed with CRP, ESR, ASDAS_CRP, BASDAI, BAS-G, BASFI, and BASMI. Lateral spine radiographs were scored for osteoproliferation and vertebral fractures using the mSASSS and Genant scores. BMD was measured in the lumbar spine and femoral neck.

Results

Vitamin D insufficiency (a serum 25(OH)D <50 nmol/L) was found in approximately 50 % of the AS patients, but serum 25(OH)D was not different from healthy controls and not significantly correlated with fecal calprotectin, gastrointestinal symptoms, disease activity parameters, mSASSS, BMD, or vertebral fractures.

Conclusions

The vitamin D status was often poor in the late winter in AS but not different from the healthy controls. No evidence for a connection between subclinical gut inflammation, malabsorption, and hypovitaminosis D was found. Serum 25(OH)D was not associated with disease activity, osteoproliferation, BMD, or vertebral fractures. We suggest that the lower vitamin D levels in AS, previously found by others, may be caused by reduced out-door UVB exposure.

     

Vitamin D and prostate cancer prognosis: a Mendelian randomization study

Purpose

Decreased vitamin D levels have been associated with prostate cancer, but it is unclear whether this association is causal. A functional single-nucleotide polymorphism (SNP) in the group-specific component (GC) gene (T > G, rs2282679) has been associated with 25-hydroxy (25-OH) vitamin D and 1.25 dihydroxy (1.25-OH2) vitamin D levels.

Methods

To examine the hypothesized inverse relationship between vitamin D status and prostate cancer, we studied the association between this SNP and prostate cancer outcome in the prospective PROCAGENE study comprising 702 prostate cancer patients with a median follow-up of 82 months.

Results

GC rs2282679 genotypes were not associated with biochemical recurrence [hazard ratios (HR) 0.91, 95 % confidence interval (CI) 0.73–1.12; p = 0.36], development of metastases (HR 1.20, 95 % CI 0.88–1.63; p = 0.25) or overall survival (HR 1.10; 95 % CI 0.84–1.43; p = 0.50).

Conclusions

A causal role of vitamin D status, as reflected by GC rs2282679 genotype, in disease progression and mortality in prostate cancer patients is unlikely.

     

Cholecalciferol Injections Are Effective in Hypovitaminosis D After Duodenal Switch: a Randomized Controlled Study

Background

By treating obesity, one of the major epidemics of this past century, through bariatric surgery, we may cause complications due to malnourishment in a growing population. At present, vitamin D deficiency is of interest, especially in patients with inferior absorption of fat-soluble nutrients after biliopancreatic diversion with duodenal switch (BPD/DS).

Methods

Twenty BPD/DS patients, approximately 4 years postoperatively, were randomized to either intramuscular supplementation of vitamin D with a single dose of 600,000 IU cholecalciferol, or a control group. Patients were instructed to limit their supplementation to 1400 IU of vitamin D and to avoid the influence of UV-B radiation; the study was conducted when sunlight is limited (December to May).

Results

Despite oral supplementation, a pronounced deficiency in vitamin D was seen (injection 19.3; control 23.2 nmol/l) in both groups. The cholecalciferol injection resulted in elevated 25[OH]D levels at 1 month (65.4 nmol/l), which was maintained at 6 months (67.4 nmol/l). This resulted in normalization of intact parathyroid hormone (PTH) levels. No changes in vitamin D or PTH occurred in the control group.

Conclusions

In BPD/DS patients, having hypovitaminosis D despite full oral supplementation, a single injection of 600,000 IU of cholecalciferol was effective in elevating vitamin D levels and normalizing levels of intact PTH. The treatment is simple and highly effective and thus recommended, especially in cases of reduced UV-B radiation.

     

Is There a Role for Visceral Adiposity in Inducing Type 2 Diabetes Remission in Severely Obese Patients Following Biliopancreatic Diversion with Duodenal Switch Surgery?

Background

Severe obesity is often characterized by ectopic fat deposition, which is related to development of type 2 diabetes (T2D). Thus, resolution of T2D may not be linearly associated with weight loss. The importance of ectopic fat reduction after bariatric surgery and T2D resolution is uncertain.

Objective

The aim of this pilot study is to compare body composition and body fat distribution in severely obese patients with or without T2D after biliopancreatic diversion with duodenal switch (BPD-DS) surgery in relation to diabetes resolution.

Methods

Sixty-two severely obese patients were evaluated at baseline, 6, and 12 months. Of these, 40 patients underwent BPD-DS surgery. Anthropometric measurements and abdominal and mid-thigh computed tomography scans were performed at each visit.

Results

Before BPD-DS surgery, obese patients with T2D had higher weight as well as greater ectopic fat deposition in the abdomen and mid-thigh level than obese patients without T2D (p?<?0.05). Resolution of T2D was 65 and 90 % at 6 and 12 months, respectively. No difference in body composition changes at 6 and 12 months could be found between patients without T2D, patients with T2D resolution, and patients who remained T2D. Resolution of T2D was associated with a greater absolute loss of visceral adipose tissue (VAT) in comparison to patients without T2D (?1175?±?570 cm³ vs. ?729?±?394 cm³ at 6 months and ?1647?±?816 cm³ vs. ?1103?±?422 cm³ at 12 months; all p?≤?0.05).

Conclusion

Ectopic fat mobilization, particularly the absolute loss of VAT, may play a major role in T2D resolution following BPD-DS surgery, regardless of the amount of weight loss.

     

Vitamin D supplementation in breastfed infants from Montréal,Canada: 25-hydroxyvitamin D and bone health effects from a follow-up study at 3 years of age

Summary

Whether infant vitamin D supplementation may have long-term bone benefits is unclear. In this study, breastfed infants who received vitamin dosages greater than 400 IU/day did not have higher bone mineralization at 3 years. This study provides important data to inform pediatric public health recommendations for vitamin D.

Introduction

North American health agencies recommend breastfed infants should be supplemented with 400 IU of vitamin D/day to support bone health. Few studies examined the long-term benefits of early life vitamin D supplementation on bone mineralization. The objective of this study was to determine if a dose-response relationship exists between infant vitamin D supplementation, vitamin D status, and bone outcomes at 3 years of age.

Methods

This was a double-blind randomized trial of 132, 1-month-old healthy, breastfed infants from Montréal, Canada, between 2007 and 2010. In this longitudinal analysis, 87 infants (66 %) returned for follow-up at 3 years of age, between 2010 and 2013. At 1 month of age, participants were randomly assigned to receive oral cholecalciferol (vitamin D₃) supplements of 400, 800, 1200, or 1600 IU/day until 12 months of age. Lumbar spine vertebrae 1–4 (LS) bone mineral density (BMD), LS and whole body bone mineral content (BMC), and mineral accretion were measured by dual-energy x-ray absorptiometry at 3 years.

Results

At follow-up, the treatment groups were similar in terms of diet, sun exposure, and demographics. There were no significant differences among the groups in LS or whole body BMC, BMD, or accretion. Although, 25(OH)D concentrations were not different among the groups, higher doses (1200 and 1600 IU/day) achieved higher 25(OH)D area under the curve from 1 to 36 months vs. 400 IU/day.

Conclusions

This is the first longitudinal follow-up of an infant vitamin D dose-response study which examines bone mineralization at 3 years of age. Dosages higher than 400 IU/day do not appear to provide additional benefits to the bone at follow-up. Larger studies with more ethnically diverse groups are needed to confirm these results.

     

Ethnicity Does Not Influence Glycemic Outcomes or Diabetes Remission After Sleeve Gastrectomy or Gastric Bypass in a Multiethnic Asian Cohort

Background

In Asia, metabolic-bariatric surgery (MBS) rates have grown rapidly in parallel with rising prevalence of obesity and type 2 diabetes (T2D).

Objective

The objective of this study was to identify factors that influence glycemic outcomes and diabetes remission 12 months after sleeve gastrectomy (SG) or gastric bypass (GB) in a multiethnic Asian cohort.

Setting

The study’s setting was in a tertiary hospital in Singapore.

Methods

Data from 145 T2D patients who had SG (37%) or GB (63%) and at least 1-year follow-up were analyzed. Diabetes remission was defined as hemoglobin A1c ≤?6.0% without diabetes medications. Analysis involved binary logistic regression to identify predictors and general linear regression for variables associated with glycemic improvement after surgery.

Results

Baseline parameters are as follows: BMI 40.0?±?7.6 kg/m², A1c 8.4?±?1.6%, diabetes duration 9.3 years, ethnic composition: Chinese (51.7%), Malay (23.4%), Indian (20.7%), Others (4.1%). 55.9% achieved diabetes remission at 1 year. Baseline A1c, baseline BMI, and diabetes duration were significant pre-operative factors for remission (cumulative R ²?=?0.334). At 12 months, percentage weight loss was similar after SG (24.1?±?7.4%) and GB (25.4?±?7.4%, p?=?0.31). Greater A1c decrease was seen with GB compared to SG (2.7?±?1.6 vs 2.0?±?1.5%, p?=?0.006), significant even after adjustment for weight loss, age, BMI, baseline A1c, and diabetes duration (p?=?0.033). Weight loss at 12 months also correlated independently with A1c reduction. Ethnicity did not influence weight loss, diabetes remission, or glycemic control after MBS.

Conclusion

Baseline A1c, baseline BMI, and diabetes duration independently predict diabetes remission after MBS. GB is more effective in controlling T2D compared to SG despite similar weight loss, whereas ethnicity does not play a significant role in the multiethnic Asian cohort.

     

Changes in Bone Mineral Density Following Weight Loss Induced by One-Anastomosis Gastric Bypass in Patients with Vitamin D Supplementation

Background

Little is known about changes in bone mineral density (BMD) following weight loss after one-anastomosis gastric bypass (OAGB) and the role of serum vitamin D and its supplementation on bone metabolism. We evaluated BMD after OAGB as a function of vitamin D supplementation with respect to a minimum threshold of 25-hydroxy-vitamin-D [25(OH)D] concentration, which could prevent or decelerate an eventual bone loss.

Methods

Fifty bariatric patients who participated in the randomized controlled trial were included in this analysis. BMD and anthropometric measurements by DXA and laboratory parameters were assessed before (T0), at 6 (T6), and 12 months (T12) after surgery.

Results

OAGB resulted in a 36% total body weight loss with a decrease in body fat and an increase in lean body mass. A significant decrease in BMD was seen in lumbar spine by 7%, left hip 13%, and total body 1%, but not in forearm. Bone turnover markers increased significantly but with normal parathyroid hormone concentrations. Weight loss was not associated with changes in BMD. A serum 25(OH)D concentration?>?50 nmol/l at T6 and T12 (adequate-vitamin-D-group; AVD) showed a significant lower bone loss, compared to the inadequate-vitamin-D-group (IVD; <?50 nmol/l). Lower bone loss in the left hip showed a strong correlation with higher 25(OH)D concentrations (r?=?0.635, p?=?0.003).

Conclusion

These findings support a dose effect of vitamin D supplementation on bone health and suggest that 25(OH)D concentrations need to be above 50 nmol/l at least during the first postoperative year to decelerate bone loss in patients undergoing OAGB.

Clinical Trial Registry Number and Website

Clinicaltrials.gov (NCT02092376) at https://clinicaltrials.gov/.EudraCT (2013-003546-16) at https://eudract.ema.europa.eu/.

     

Prevalence and Determinants of Vitamin D Deficiency Among the Overweight and Obese Singaporeans Seeking Weight Management Including Bariatric Surgery: a Relationship with Bone Health

Purpose

Low vitamin D status is prevalent worldwide and has been linked to a variety of pathologies including obesity in adults. The severity of vitamin D deficiency amongst the overweight and obese Singaporeans is not well documented. The purpose of this prospective observational study was to assess the prevalence and determinants of vitamin D deficiency in a multi-ethnic Asian population referred for weight management, including those seeking bariatric surgery.

Materials and Methods

This was a cross-sectional study conducted among 111 consecutive subjects referred to a single institution weight management service in Singapore. The data collected included their anthropometric data, body mass index (BMI), body fat percentage, waist circumference, 25-hydroxyvitamin D [25(OH)D] and other bone turnover markers.

Results

The average BMI among the 111 subjects was 40.1?±?8.2 kg/m² and mean age of 40?±?10 years. Vitamin D deficiency was found in 75.7% of the population. There was a significant negative association of vitamin D with adiposity markers including BMI (r?=???0.31), body fat percentage (r?=???0.34) and waist circumference (r?=???0.26). Predictors of vitamin D deficiency included age?>?50 years, female gender, waist circumference and body fat percentage.

Conclusion

Vitamin D deficiency is prevalent among this target population in Singapore regardless of ethnicity. In particular, the elderly, females, those with larger waist circumference and body fat percentage were significantly associated with lower serum 25(OH)D level. Hence, routine screening for the overweight and obese subjects in multi-ethnic Singapore seeking weight management is indicated.