High parathyroid hormone,but not low vitamin D concentrations,expose elderly inpatients to hypertension

Aim: Serum parathyroid hormone (PTH) and 25‐hydroxyvitamin D (25OHD) concentrations might contribute to blood pressure (BP) levels. Mixed results in previous literature could be due to the failure to consider both these hormones concurrently, despite their long‐known relationship. Our objective was to examine the association of serum intact PTH and 25OHD concentrations with BP levels amongst older inpatients, while accounting for each other. Methods: The participants were 284 Caucasian older inpatients with no suspicion of primary hyperparathyroidism (mean age 85.87 ± 5.90 years; 65.8% female) admitted to the geriatric acute care unit of Angers University Hospital, France. They were divided into two groups according to the existence of hypertension (i.e. systolic blood pressure [SBP] >140 mmHg, or diastolic blood pressure [DBP] >90 mmHg). Age, sex, numbers of chronic diseases and of drugs taken daily, use of antihypertensive or corticosteroid drugs and of calcium supplements/vitamin D, thyroid‐stimulating hormone and albumin concentrations, creatinine clearance, and season tested were used as covariables. Results: Hypertensive participants (n = 106) had higher intact PTH concentrations than normotensive patients (P = 0.044). There was a positive linear association of BP with intact PTH concentrations (adjusted β = 0.08, P = 0.015 for SBP; adjusted β = 0.05, P = 0.044 for DBP), but not with vitamin D. Serum intact PTH concentration, unlike 25OHD, was associated with hypertension (adjusted OR 1.01, P = 0.038). Conclusions: Irrespective of 25OHD, PTH was associated with hypertension by increasing both SBP and DBP. Geriatr Gerontol 2013; 13: 783–791 .     

Nocturnal diastolic blood pressure decline is associated with higher 25-hydroxyvitamin D level and standing plasma renin activity in a hypertensive population

Patients with nondipper hypertension are known to carry a high risk of cardiovascular complications. Vitamin D deficiency is associated with hypertension. Because vitamin D deficiency activates the renin–angiotensin–aldosterone system (RAAS), we hypothesized that this vitamin would interact with the RAAS to influence blood pressure (BP) in nondipper hypertensive patients. We performed a cross-sectional analysis of 1,007 outpatients with hypertension (HTN). Dipper and nondipper patterns were detected, and the two groups were matched for clinical, laboratory, 25-hydroxyvitamin D (25OHD) levels, and ambulatory blood pressure recording. Plasma renin activity (PRA), angiotensin II, and plasma aldosterone concentration (PAC) were assessed in 174 patients treated with calcium channel blockers or no medication. The mean 25OHD concentration in the entire study population was 12.3ng/dL, and the prevalence of vitamin D deficiency was 87.0%. Dipper and nondipper HTN were noted in 187 patients (24.6%) and 573 patients (75.4%). 25OHD levels were similar between nondipper and dipper HTN groups. Forward stepwise logistic regression analysis showed that BMI and age were independent predictors of nondipper HTN. Neither 25OHD levels nor RAAS components were included in the model. In correlation analyses, nocturnal decline of diastolic BP was positively associated with 25OHD levels and standing PRA (r = 0.152 p = 0.045, r = 0.165 p = 0.038, respectively). The present study showed that vitamin D deficiency was astonishingly prevalent in hypertensive subjects residing in Xinjiang, China. There may be a weakly association of nocturnal DBP decline with 25OHD levels and standing PRA levels. We found no association between vitamin D deficiency and nondipper HTN.     

Vitamin D dependent effects of APOA5 polymorphisms on HDL cholesterol

ObjectivesVitamin D and serum lipid levels are risk factors for cardiovascular disease. We sought to determine if vitamin D (25OHD) interacts at established lipid loci potentially explaining additional variance in lipids.Methods1060 individuals from Utah families were used to screen 14 loci for SNPs potentially interacting with dietary 25OHD on lipid levels. Identified putative interactions were evaluated for (1) greater effect size in subsamples with winter measures, (2) replication in an independent sample, and (3) lack of gene–environment interaction for other correlated dietary factors. Maximum likelihood models were used to evaluate interactions. The replicate sample consisted of 2890 individuals from the Family Heart Study. Putative 25OHD receptor binding site modifying SNPs were identified and allele-specific, 25OHD-dependent APOA5 promoter activity examined using luciferase expression assays. An additional sample with serum 25OHD measures was analyzed.ResultsAn rs3135506–25OHD interaction influencing HDL-C was identified. The rs3135506 minor allele was more strongly associated with low HDL-C in individuals with low winter dietary 25OHD in initial and replicate samples (p = 0.0003 Utah, p = 0.002 Family Heart); correlated dietary factors did not explain the interaction. SNP rs10750097 was identified as a putative causative polymorphism, was associated with 25OHD-dependent changes in APOA5 promoter activity in HEP3B and HEK293 cells (p < 0.01), and showed similar interactions to rs3135506 in family cohorts. Linear interactions were not significant in samples with serum 25OHD measures; however, genotype-specific differences were seen at deficient 25OHD levels.ConclusionsA 25OHD receptor binding site modifying APOA5 promoter polymorphism is associated with lower HDL-C in 25OHD deficient individuals.     

Adiposity and the relationship between vitamin D and blood pressure

ObjectiveCirculating vitamin D (25OHD) concentrations are negatively associated with blood pressure (BP) but little is known about the mechanisms for this relationship. Adiposity is positively associated with BP and inversely with circulating 25OHD concentrations but no studies have assessed the relationship between plasma 25OHD and adiposity on BP. The goal of this study is to investigate if the association between plasma 25OHD and BP is mediated by adiposity.Materials/MethodsThe relationship between plasma 25OHD, systolic and diastolic BP, and adiposity [BMI, waist circumference, visceral adipose tissue (VAT)] was assessed in a multi-ethnic cross-sectional study of Aboriginal (n = 151), Chinese (n = 190), European (n = 170), and South Asian (n = 176) participants by linear regression models.ResultsPlasma 25OHD concentrations were negatively associated with systolic (standardized B = ? 0.191, P < 0.001) and diastolic BP (standardized B = ? 0.196, P < 0.001) in models adjusted for age, sex, ethnicity, family history of CVD, smoking status, alcohol consumption, and physical activity. The negative relationship between plasma 25OHD concentrations and systolic and diastolic BP was attenuated after the addition of BMI, waist circumference, and VAT to the models, but the relationship remained significant. Plasma 25OHD concentrations accounted for 0.7% and 0.8% of the variance in systolic and diastolic BP, respectively.ConclusionThese findings suggest that the relationship between vitamin D and BP is independent of adiposity. Further studies are required to determine the mechanisms by which vitamin D affects BP.     

Muscle pain and serum creatine kinase are not associated with low serum 25(OH) vitamin D levels in patients receiving statins

Objective Vitamin D deficiency has been associated in some studies with nonspecific musculoskeletal pain and, more specifically, with statin‐induced myalgia, which was ameliorated by high‐dose vitamin D supplements. Our objective was to explore the association between vitamin D status and statin‐induced myalgia and elevation of serum creatine kinase (CK). Design Retrospective cohort study, based on the electronic database of a health maintenance organization. Patients Six thousand eight hundred and eight patients (71·5% women) to whom statins were dispensed during 2008 and who had ≥1 CK and 25‐hydroxy vitamin D (25OHD) levels measured during statin exposure. Of these, 376 patients (5·5%) had switched from a first‐line statin to atorvastatin because of muscle pain (n = 220) or other reasons (n = 156). Measurements In the entire cohort, we compared serum CK levels among serum 25OHD quartiles. In addition, we compared CK and 25OHD levels among patients with myalgia, other switchers and nonswitchers. Results The median 25OHD level in the entire cohort was 21·8 ng/ml [interquartile range (IQR), 16·3–27·4]. CK levels were marginally lower in patients in the lowest 25OHD quartile [median CK (IQR) in 25OHD quartiles 1–4, 87 (61–130), 90 (65–131), 91 (65–132) and 91 (67–131) IU/ml, respectively; P = 0·007]. 25OHD levels in statin switchers were similar to those in nonswitchers; moreover, there were no differences in 25OHD among switchers with muscle pain and other switchers. Conclusion Our findings do not support an association between low 25OHD levels and statin‐induced myalgia or CK elevation.     

Serum 25-hydroxyvitamin D, ethnicity, and blood pressure in the Third National Health and Nutrition Examination Survey

BACKGROUND: Populations with low vitamin D status, such as blacks living in the US or UK, have increased blood pressure (BP) compared with whites. We analyzed the association between serum 25-hydroxyvitamin D (25OHD) and BP to determine whether low 25OHD explains any of the increased BP in blacks. METHODS: The Third US National Health and Nutrition Examination Survey (NHANES III) is a cross-sectional survey representative of the US civilian population during 1988 to 1994. Analyses were restricted to 12,644 people aged > or =20 years with measurements of BP and 25OHD, after excluding those on hypertensive medication. RESULTS: Adjusted mean serum 25OHD was lowest in non-Hispanic blacks (49 nmol/L), intermediate in Mexican Americans (68 nmol/L), and highest in non-Hispanic whites (79 nmol/L). When participants were divided into 25OHD quintiles, mean (standard error) systolic BP was 3.0 (0.7) mm Hg lower (P = .0004) and diastolic BP was 1.6 (0.6) mm Hg lower (P = .011) for participants in the highest quintile (25OHD > or =85.7 nmol/L) compared with the lowest (25OHD < or =40.4 nmol/L), adjusting for age, sex, ethnicity, and physical activity. Further adjustment for body mass index (BMI) weakened the inverse association between 25OHD and BP, which remained significant for systolic BP (P < .05). The inverse association between 25OHD and systolic BP was stronger in participants aged > or =50 years than younger (P = .021). Ethnic differences in 25OHD explained about half of the increased hypertension prevalence in non-Hispanic blacks compared with whites. CONCLUSIONS: Vitamin D status, which is amenable to intervention by safely increasing sun exposure or vitamin D supplementation, was associated inversely with BP in a large sample representative of the US population.     

Transjugular aspiration liver biopsy performed by hepatologists trained in HVPG measurements is safe and provides important diagnostic information

BackgroundTransjugular liver biopsy (TJLB) represents an alternative to percutaneous liver biopsy especially in patients with impaired coagulation and ascites.AimsTo describe safety and diagnostic yield of aspiration TJLB performed by hepatologists experienced in hepatic venous pressure gradient (HVPG) measurements.Methods445 TJLB of 399 patients between 01/2007–12/2016 were retrospectively assessed.ResultsHistological diagnosis was obtained in 423 (95.1%) biopsies — including 11 (100%) patients with acute liver failure and 34 (97.1%) patients after liver transplantation. A median number of 5 portal tracts (interquartile range:2–9) was obtained. HVPG negatively correlated with sample length (Spearman ρ = −0.310; p < 0.001) and number of portal tracts (ρ = −0.212; p < 0.001).Among n = 151 patients with unknown etiology of liver disease, etiology was successfully identified on liver histology in 126 patients (83.4%).Complications occurred in 28 biopsies (6.3%) including 25 (5.6%) minor and 3 (0.7%) major complications. No deaths due to TJLB were observed.Neither the presence of ascites (6.6% complications) nor of coagulopathy (platelets<50G/L and/or prothrombin time<50%; 4.8% complications) increased the risk for complications.ConclusionsTJLB performed by hepatologists experienced in HVPG measurements is safe - even in patients with ascites or coagulopathy. TJLB has good diagnostic value for histological evaluation of liver disease and acute liver failure.     

Vitamin D deficiency and changes in serum vitamin D levels with treatment among tuberculosis patients in South Korea

Background and objective: Vitamin D deficiency has been reported to be associated with the development of active tuberculosis (TB), but many discrepancies exist among studies. The aims of this study were to compare the frequency of vitamin D deficiency in a Korean population of TB patients and control subjects, and to monitor the changes in vitamin D levels during TB treatment. Methods: Patients with newly diagnosed TB were prospectively enrolled. In addition, healthy volunteers or patients with diseases other than TB were enrolled as controls. Baseline serum 25‐hydroxyvitamin D (25‐OHD) levels were measured in both groups and compared. In the TB patients, measurements of serum 25‐OHD were repeated 1 month after the initiation of treatment and again after completion of treatment. Results: In total, 116 patients with TB and 86 control subjects were recruited. The median 25‐OHD concentration was not different in TB patients at diagnosis (13.9 ng/mL; interquartile range (IQR) 8.80–21.8) compared with control subjects (13.2 ng/mL; IQR 9.6–19.3) (P = 0.97). The frequency of vitamin D deficiency (≤10 ng/mL) was also not different in TB patients (36.2%) compared with controls (27.3%) (P = 0.21). In TB patients, the median 25‐OHD concentration decreased significantly during treatment, to 12.5 ng/mL at 1 month and 11.0 ng/mL on completion of treatment (P = 0.01). Conclusions: Vitamin D levels do not appear to be associated with the development of TB in the Korean population. The median 25‐OHD concentration decreased after treatment for TB.     

Limitations of platform assays to measure serum 25OHD level impact on guidelines and practice decision making

ContextLiquid Chromatography Mass Spectroscopy (LC-MS/MS) is the preferred method to measure 25 hydroxyvitamin D (25OHD) levels, but laboratories are increasingly adopting automated platform assays.ObjectiveWe assessed the performance of commonly used automated immunoassays, with that of LC-MS/MS, and the National Institute of Standards and Technology (NIST) reference values, to measure 25OHD levels.Methods/SettingWe compared serum 25OHD levels obtained from 219 elderly subjects, enrolled in a vitamin D trial, using the Diasorin Liaison platform assay, and the tandem LC-MS/MS method. We also assessed the performance of the Diasorin and Roche automated assays, expressed as mean % bias from the NIST standards, based on the vitamin D External Quality Assessment Scheme (DEQAS) reports, from 2013 to 2017.ResultsSerum 25OHD levels were significantly lower in the Diasorin compared to LC-MS/MS assay at baseline, 18.5 ± 7.8 vs 20.5 ± 7.6 ng/ml (p < 0.001), and all other time points. Diasorin (25OHD) = 0.76 × LC-MS/MS (25OHD) + 4.3, R² = 0.596. The absolute bias was independent of 25OHD values, and the pattern unfit for any cross-calibration. The proportion of subjects considered for vitamin D treatment based on pre-set cut-offs differed significantly between the 2 assays. There also was wide variability in the performance of both automated assays, compared to NIST reference values.ConclusionThe performance of most widely used automated assays is sub-optimal. Our findings underscore the pressing need to re-consider current practices with regard to 25OHD measurements, interpretation of results from research studies, meta-analyses, the development of vitamin D guidelines, and their relevance to optimizing health.     

Vitamin D and heart failure: A two-sample mendelian randomization study

Background and aimsThe relationship between vitamin D and heart failure (HF) has attracted significant interest, but the association between the two in previous studies remains uncertain. Therefore, we used two-sample Mendelian randomization (MR) to investigate a causal association between 25-hydroxyvitamin D (25OHD) and HF risk.Methods and resultsThis study utilized summary statistics from the most extensive genome-wide association studies for 25OHD and HF. To make the results more reliable, we used several methods based on three assumptions for MR analysis. We also used the multivariable MR adjusting for hypertension, BMI, diabetes, chronic kidney disease to further elucidate the association between 25OHD and HF. Considering the potential pleiotropy, we performed an MR analysis with conditionally independent genetic instruments at core genes to further determine the relationship between vitamin D and heart failure. We found that per 1 SD increase in standardized log-transformed 25OHD level, the relative risk of HF decreased by 16.5% (OR: 0.835, 95% Cl: 0.743–0.938, P = 0.002), and other MR methods also showed consistent results. The multivariable MR also reported that per 1 SD increase in standardized log-transformed 25OHD level, the relative risk of HF decreased. And the scatter plots showed a trend towards an inverse MR association between 25OHD levels, instrumented by the core 25OHD genes, and HF.ConclusionIn summary, we found a potential inverse association between elevated 25OHD levels and the risk of HF, which suggested that timely 25OHD supplementation or maintaining adequate 25OHD concentrations may be an essential measure for HF prevention in the general population.     

Systolic blood pressure alterations during hyperinsulinemia are related to changes in ionized calcium status

Background:A correlation between changes in ionized calcium status and changes in systolic blood pressure (BP) has previously been observed during induced euglycemic hyperinsulinemia in patients with essential hypertension. The objective of this study was to evaluate associations between alterations in ion status and BP changes during euglycemic hyperinsulinemia in healthy normotensive subjects.Methods:Ion status in plasma and BP were measured before and at the end of euglycemic hyperinsulinemic clamp tests performed in 41 healthy normotensive volunteers.Results:During euglycemic hyperinsulinemia plasma sodium increased by 1% (P < .0001), ionized calcium (iCa) by 5% (P < .0001), and ionized magnesium (iMg) by 4% (P < .01), whereas potassium decreased by 10% (P < .0001). The changes in plasma iCa and iMg correlated significantly to changes in systolic BP (r = −0.38, P < .02; r = −0.32, P < .05, respectively), but the correlation between changes in iMg and changes in systolic BP did not remain significant in a multiple regression model. The glucose infusion rate correlated inversely to the change in iMg (r = −0.39, P < .01).Conclusions:The group mean systolic BP was unaltered during induced euglycemic hyperinsulinemia in healthy normotensive subjects; however, a more pronounced increase in the circulating iCa concentration was associated with a greater decline in systolic BP, which is in accordance with previous observations in patients with essential hypertension. The group mean diastolic BP was decreased; however, the lowered diastolic BP was not correlated to changes in ion status.     

Prophylactic vitamin D in healthy infants: assessing the need

The objective was to evaluate the need for vitamin D prophylaxis in healthy infants. This was a prospective and randomized study performed at primary care clinics. Eighty-eight full-term 1-month-old healthy infants were randomly assigned to receive (n = 41) or not (n = 47) 402 IU/d of vitamin D for 1 year. Primary outcome measures were serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) concentrations at 3, 6, and 12 months of age; secondary measures included data on feeding, habitat, season of birth, sun exposure, and physical examination. At 3 and 6 months of age, serum 25OHD levels (±SD) were significantly higher (P < .001) in the prophylaxis group. In the group without prophylaxis, serum 25OHD increased with age; and breast-fed infants aged 3 months had the lowest value (20.2 ± 9.4 ng/mL), which was significantly (P = .001) lower than that of formula-fed infants (35.0 ± 9.7 ng/mL). The PTH levels were not influenced by the prophylaxis or feeding. No influence of either the habitat or season of birth on serum 25OHD concentrations was demonstrated. No infant had clinical signs of vitamin D deficiency. Serum 25OHD and PTH concentrations were weakly but significantly correlated (r = −0.29, P = .009) at 3 months of age. Healthy infants without vitamin D prophylaxis had lower circulating concentrations of 25OHD at 3 and 6 months of age, the lowest value being found in 3-month breast-fed infants. The clinical relevance of these findings is probably negligible because serum 25OHD levels spontaneously increased with age and were not associated with high serum PTH. Clinical manifestations of rickets were not observed.     

Vitamin D levels in IBD: a randomised trial of weight-based versus fixed dose vitamin D supplementation

Abstract

Objectives: Body weight is one of the factors affecting blood levels of 25-hydroxyvitamin D (25OHD). The aim of this study was to establish whether a vitamin D (vitD) weight-based dosing is more appropriate to a fixed daily dose in patients with inflammatory bowel disease (IBD).

Materials/methods: This was an open label randomised trial. Patients with IBD were assigned to receive oral cholecalciferol at a dose of 28?IU/kg (IU/kg) or 2000?IU per day (IU/day) for 12?weeks during winter months. 25OHD plasma levels and other biochemical parameters were measured at baseline and after supplementation period. The primary outcome measure was 25OHD level after a follow-up period.

Results: A total of 173 patients were analysed. The mean BMI was 25.5?±?5.1 and initial mean 25OHD level was 62.7?±?25.5?nmol/l. A similar increase (9.7?±?26.9 vs 9.8?±?26.7?nmol/l) in 25OHD levels occurred both in IU/kg and IU/day group. The proportion of subjects with normal and sub-normal levels following the substitution was comparable irrespective of body weight. The change in 25OHD level correlated positively only with the dose of vitD (p?<?.001) and negatively with the baseline 25OHD level (p?<?.001). A sustained 25OHD level of 75?nmol/l corresponds with a calculated daily vitD dose of 2034?IU.

Conclusions: Weight-based dosing of vitamin D is not superior to a fixed dose in order to maintain stable 25OHD levels in IBD patients. Cholecalciferol dose of 2,000?IU/day is safe and sufficient during winter period.     

25-Hydroxyvitamin D is lower in deprived groups, but is not associated with carotid intima media thickness or plaques: results from pSoBid

ObjectiveThe association of the circulating serum vitamin D metabolite 25-hydroxyvitamin D (25OHD) with atherosclerotic burden is unclear, with previous studies reporting disparate results.MethodPsychological, social and biological determinants of ill health (pSoBid) is a study of participants aged 35–64 years from Glasgow who live at extremes of the socioeconomic spectrum. Vitamin D deficiency was defined as 25OHD < 25nmol/L, as per convention. Cross-sectional associations between circulating 25OHD concentrations and a range of socioeconomic, lifestyle, and biochemistry factors, as well as carotid intima media thickness (cIMT) and plaque presence were assessed in 625 participants.ResultsGeometric mean levels of circulating 25OHD were higher among the least deprived (45.6 nmol/L, 1-SD range 24.4–85.5) versus most deprived (34.2 nmol/L, 1-SD range 16.9–69.2; p < 0.0001). In the least deprived group 15% were “deficient” in circulating 25OHD versus 30.8% in the most deprived (χ² p < 0.0001). Log 25OHD was 27% lower among smokers (p < 0.0001), 20% higher among the physically active versus inactive (p = 0.01), 2% lower per 1 kg/m² increase in body mass index (BMI) (p < 0.0001), and showed expected seasonal variation (χ² p < 0.0001). Log 25OHD was 13% lower in the most versus least deprived independent of the aforementioned lifestyle confounding factors (p = 0.03). One unit increase in log 25OHD was not associated with atherosclerotic burden in univariable models; cIMT (effect estimate 0.000 mm [95% CI ?0.011, 0.012]); plaque presence (OR 0.88 [0.75, 1.03]), or in multivariable models.ConclusionThere is no strong association of 25OHD with cIMT or plaque presence, despite strong evidence 25OHD associates with lifestyle factors and socioeconomic deprivation.     

Association between vitamin D status and physical performance: the InCHIANTI study

BACKGROUND: Vitamin D status has been hypothesized to play a role in musculoskeletal function. Using data from the InCHIANTI study, we examined the association between vitamin D status and physical performance. METHODS: A representative sample of 976 persons aged 65 years or older at study baseline were included. Physical performance was assessed using a short physical performance battery (SPPB) and handgrip strength. Multiple linear regression was used to examine the association between vitamin D (serum 25OHD), parathyroid hormone (PTH), and physical performance adjusting for sociodemographic variables, behavioral characteristics, body mass index, season, cognition, health conditions, creatinine, hemoglobin, and albumin. RESULTS: Approximately 28.8% of women and 13.6% of men had vitamin D levels indicative of deficiency (serum 25OHD < 25.0 nmol/L) and 74.9% of women and 51.0% of men had vitamin D levels indicative of vitamin D insufficiency (serum 25OHD < 50.0 nmol/L). Vitamin D levels were significantly associated with SPPB score in men (beta coefficient [standard error (SE)]: 0.38 [0.18], p =.04) and handgrip strength in men (2.44 [0.84], p =.004) and women (1.33 [0.53], p =.01). Men and women with serum 25OHD < 25.0 nmol/L had significantly lower SPPB scores whereas those with serum 25OHD < 50 nmol/L had significantly lower handgrip strength than those with serum 25OHD > or =25 and > or =50 nmol/L, respectively (p <.05). PTH was significantly associated with handgrip strength only (p =.01). CONCLUSIONS: Vitamin D status was inversely associated with poor physical performance. Given the high prevalence of vitamin D deficiency in older populations, additional studies examining the association between vitamin D status and physical function are needed.     

ORIGINAL ARTICLE: Association between 25‐hydroxyvitamin D,somatic muscle weakness and falls risk in end‐stage renal failure

Objective Suboptimal levels of 25‐hydroxyvitamin D (25OHD) are common in haemodialysis patients (Chronic Kidney disease‐5D: CKD‐5D) and may be associated with reduced muscle strength and increased falls risk. We tested the hypothesis that 25OHD levels may be independently associated with falls risk in CKD‐5D. Background Supplementation with calcium and cholecalciferol reduces hip and other nonvertebral fractures in elderly individuals, and this effect may in part be attributable to reduction in falls frequency. The relationship between 25OHD and falls risk has not been investigated in CKD‐5D. Design and Patients This is a cross‐sectional study of 25 CKD‐5D patients with predialysis 25OHD, 1,25‐dihydroxyvitamin D (1,25(OH)₂D) and intact parathyroid hormone (iPTH) measurement. Falls risk was assessed by quadriceps muscle strength, FallsScreen^© test (FST), Berg Balance Scale (BBS), timed ‘up and go’ (TUG) test, Modified Barthel Index (MBI) and Falls Efficacy Scale (FES). Results Mean age was 69·8 ± 12·1 years, and median time on dialysis was 3·1 years. Median 25OHD level was 55·3 nmol/l (range 20·8–125·8 nmol/l). Muscle strength was significantly positively correlated with 25OHD (P = 0·024) but not with 1,25(OH)₂D (P = 0·477) or PTH (P = 0·461). Statistically significant correlation between 25OHD levels and FST (P = 0·028) plus MBI (P = 0·0046) was noted. No significant correlation was detected between falls risk and 1,25(OH)₂D or PTH. Conclusions Suboptimal levels of 25OHD in CKD‐5D are associated with reduced quadriceps muscle strength and increased falls risk. 25OHD may be more important than the active renal metabolite 1,25(OH)₂D for muscle strength with implications for vitamin D choice and goals of supplementation. Further investigation is required to examine effectiveness of calciferol supplementation on the incidence of falls in CKD‐5D.     

Maternal vitamin D deficiency,ethnicity and gestational diabetes

Aims Vitamin D deficiency has been linked to impaired glucose metabolism. We determined whether serum 25‐hydroxyvitamin D (25OHD) is associated with glucose metabolism in pregnant women and the effect of ethnicity on this relationship. Methods We analysed serum 25OHD concentrations in 307 pregnant women attending a metropolitan obstetric clinic between October 2003 and May 2005. Measurements from 264 of the women were taken at the time of glucose tolerance testing at mid‐gestation, a population therefore at increased risk for gestational diabetes. Pearson correlation analysis was used to test for univariate linear relationships between the natural log of serum 25OHD (ln‐25OHD) and other variables. Multiple regression analysis was used to adjust for confounding factors. Results Mean serum 25OHD concentration was 53.8 ± 23.9 nmol/l (sd ). Ln‐25OHD was negatively correlated with serum parathyroid hormone as expected (r ?0.24, confidence intervals ?0.35 to ?0.12). Ln‐25OHD was also negatively correlated with fasting plasma glucose (r?0.20, ?0.31 to ?0.08), fasting insulin (r ?0.20, ?0.31 to ?0.08) and insulin resistance as calculated by homeostatis model assessment (r ?0.21, ?0.32 to ?0.09). The association between fasting glucose and log‐transformed 25OHD concentration was of borderline significance after accounting for ethnicity, age and body mass index in multivariate analyses (?0.13, ?0.26 to 0.01). The odds ratio of gestational diabetes in women with 25OHD < 50 nmol/l did not reach statistical significance (1.92, 95% confidence interval 0.89–4.17). Conclusions Maternal 25OHD concentrations are inversely related to fasting glucose, although further studies are required to establish whether this is independent of the effects of ethnic background.     

Serum 25-hydroxyvitamin D levels and the metabolic syndrome in older persons: a population-based study

Background Recent evidence indicates that a lower plasma level of 25‐hydroxyvitamin D (25 OHD) is associated with a higher risk of the metabolic syndrome. It has not been studied in older people with a high prevalence of vitamin D insufficiency. Objective This study investigates the association between vitamin D status and the metabolic syndrome in community‐dwelling older persons in the Netherlands. Design and patients The study is part of the Longitudinal Aging Study Amsterdam, an ongoing cohort study in a representative sample of Dutch older persons. A total of 1286 subjects (629 men and 657 women) between the ages of 65 and 88 years participated in the study. Measurements Metabolic syndrome (U.S. National Cholesterol Education Program definition) and its individual components were assessed as well as serum 25 OHD levels. Results Among the participants, the prevalence of the metabolic syndrome was 37·0%. The mean 25 OHD level was 53·3 nm ; 47·8% had 25 OHD levels below 50 nm . There was a significantly increased risk of the metabolic syndrome in the subjects with serum 25 OHD levels below 50 nm , compared with that of subjects with levels over 50 nm [odds ratio (OR) = 1·54; 95% confidence interval (CI) 1·23–1·94]. After adjustment for confounders, age, sex, season, years of education, alcohol use, total activity, smoking and PTH, the OR was 1·29 (95% CI 1·00–1·68). The association between vitamin D deficiency and the metabolic syndrome was mainly determined by the components low HDL and (high) waist circumference. Conclusions Vitamin D deficiency is common in the older population in the Netherlands, and subjects with serum 25 OHD below 50 nm have a higher risk of the metabolic syndrome.     

Exposición solar en la enfermedad inflamatoria intestinal ambulatoria: factores predictivos y correlación con la concentración sérica de vitamina D

IntroductionSunlight exposure is the main source of vitamin D. Our aim was to describe both sun exposure and sun protection behaviour in a series of patients with inflammatory bowel disease (IBD), and to study their potential association with vitamin D concentration.Patients and methodsA cross sectional, observational study. The clinical-demographic variables were obtained via clinical interviews and medical history review. The sunlight exposure assessment was carried out using the Sun Exposure Questionnaire and the concentration of 25-hydroxy vitamin D (25OHD) was measured by an electro-chemiluminescence immunoassay. Questionnaires were conducted on quality of life, physical activity, weekly vitamin D intake and sun protection behaviour.Results149 patients were included. In 69% of patients, deficient or insufficient 25OHD values were recorded. 67% showed low sun exposure. A modest significant correlation was observed between the total score of the solar exposure questionnaire and the 25OHD concentration in the complete series (r = 0.226, P = .006) and in the summer (r = 0.274, P = .01). The sun protection behaviour questionnaire score did not influence the 25OHD concentration. In the multivariate analysis, only the presence of clinical activity was associated with low sun exposure (OR = 3.23).DiscussionSun exposure according to the questionnaire used was low, was associated with the presence of clinical activity and was weakly correlated with serum 25OHD concentration. More studies are needed to explore the use of individual questionnaires for sun exposure and its relationship with vitamin D in patients with IBD.