Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome

Background

Dry eye syndrome (DES) is a common tear film and ocular surface disease that results in discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. Systemic diseases associated with DES include diabetes mellitus, rheumatoid arthritis, depression, anxiety, thyroid disease, allergic diseases, irritable bowel syndrome, chronic pain syndrome, and hyperlipidemia. Interestingly, it has been found that most of these are associated with low levels of serum 25-hydroxyvitamin D (25(OH)D) or inadequate sunlight exposure.

Methods

In this cross-sectional data analysis, noninstitutionalized adults aged ≥19 years (N = 17,542) who participated in Korean National Health and Nutrition Examination Survey 2010–2012 were included. Information regarding duration of sunlight exposure was collected from the survey participants. Serum 25(OH)D and zinc levels were measured. The confounding variables were age, gender, sunlight exposure time, region of residence, obesity, serum 25(OH)D level, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and walking exercise.

Results

Mean serum 25(OH)D levels of subjects with and without DES were 16.90 ± 6.0 and 17.52 ± 6.07 (p<0.001). Inadequate sunlight exposure time (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.307–1.848), urban residence (OR, 1.669; 95% CI, 1.456–1.913), indoor occupation (OR, 1.578; 95% CI, 1.389–1.814), and low serum 25(OH)D level (OR, 1.158; 95% CI, 1.026–1.308) were the risk factors for DES. After adjusting for age, sex, obesity, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and occupation, low serum 25(OH)D level (OR, 1.178; 95% CI, 1.010–1.372) and deficient sunlight exposure time (OR, 1.383; 95% CI, 1.094–1.749) were the risk factors for diagnosed DES.

Conclusion

Low serum 25(OH)D levels and inadequate sunlight exposure are associated with DES in Korean adults. These results suggest that sufficient sunlight exposure or vitamin D supplementation may be useful in DES treatment.     

Low 25-Hydroxyvitamin D Levels Are Associated with Infections and Mortality in Patients with Cirrhosis

Background & Aims

Vitamin D, best known to regulate bone mineralization, has numerous additional roles including regulation inflammatory pathways. Recently, an increased incidence of 25-hydroxyvitamin D3 (25(OH)D₃) deficiency has been found in subjects suffering from liver diseases. We here investigated if low vitamin D levels might be associated with prognosis, inflammation and infectious complications in patients with cirrhosis.

Methods

We performed a prospective cohort study investigating the relation between 25(OH)D₃ levels and stages of cirrhosis, mortality and complications of cirrhosis, including infections.

Results

251 patients with cirrhosis were enrolled into the present prospective cohort study. 25(OH)D₃ levels were quantified by radioimmunoassay from serum samples obtained at study inclusion. The mean follow-up time was 411 ± 397 days with a range of 1-1382 days. 30 (12.0%) patients underwent liver transplantation and 85 (33.8%) individuals died within the study. The mean serum 25(OH)D₃ concentration was 8.93 ± 7.1 ng/ml with a range of 1.0 to 46.0 ng/ml. 25(OH)D₃ levels differed significantly between Child Pugh scores and showed a negative correlation with the model of end stage liver disease (MELD) score. Patients with decompensated cirrhosis and infectious complications, had significantly lower 25(OH)D₃ levels compared to subjects without complications. Low 25(OH)D₃ was associated with mortality in uni- as well as multivariate Cox regression models.

Conclusions

25(OH)D₃ deficiency is associated with advanced liver disease and low 25(OH)D₃ levels are an indicator for a poor outcome and are associated with infectious complications.     

Association of Low Serum 25-Hydroxyvitamin D Levels in Pregnancy with Glucosehomeostasis and Obstetric And Newborn Outcomes

ObjectiveTo evaluate the association of maternal serum 25-hydroxyvitamin D (25[OH]D) status with glucose homeostasis and obstetric and newborn outcomes in women screened for gestational diabetes mellitus (GDM).MethodsConsecutive women were screened for GDM at 24 to 28 weeks’ gestation during the months of maximal sunlight exposure in Spain (June through September). Serum 25(OH)D levels and parameters of glucose homeostasis were measured. Outcomes of the delivery and newborn were collected.ResultsTwo hundred sixty-six women were screened. Vitamin D deficiency (25[OH]D < 20 ng/mL) was observed in 157 women (59%). We observed an inverse correlation between 25(OH)D levels and hemoglobin A_1c, homeostasis model assessment of insulin resistance, serum insulin, and fasting and 1-hour oral glucose tolerance test glucose levels (P <.001). With a 25(OH)D concentration less than 20 ng/mL, the odds ratios were 3.31 for premature birth (95% confidence interval, 1.52-7.19; P <.002) and 3.93 for cesarean delivery (95% confidence interval, 2.00-7.73; P <.001). A 25(OH)D concentration of 20 ng/mL had 79% sensitivity and 51% specificity for cesarean delivery and 80% sensitivity and 45% specificity for premature birth. The cutoffs with the best combination of sensitivity and specificity were 16 ng/mL for cesarean delivery (62.9% sensitivity and 61.2% specificity) and 14 ng/mL for premature birth (66.7% sensitivity and 71.0% specificity).ConclusionsIn the population we sampled, vitamin D deficiency is very common during pregnancy. Lower 25(OH)D levels are associated with disorders of glucose homeostasis and adverse obstetric and newborn outcomes.(Endocr Pract. 2012;18:676-684)     

Treatment with 50000 IU Vitamin D2 Every Other Week and Effect on Serum 25-Hydroxyvitamin D2, 25-Hydroxyvitamin D3, and Total 25-Hydroxyvitamin D in Aclinical Setting

ObjectiveTo examine the effect of 50 000 IU-vitamin D₂ supplementation in a clinical setting on serum total 25-hydroxyvitamin D (25[OH]D), 25-hydroxyvitamin D₂ (25[OH]D₂), and 25-hydroxyvitamin D₃ (25[OH]D₃).MethodsThis retrospective cohort study was performed in an urban tertiary referral hospital in Boston, Massachusetts. Patients who had been prescribed 50 000 IU vitamin D₂ repletion and maintenance programs were identified through a search of our electronic medical record. Baseline and follow-up total serum 25(OH)D, 25(OH)D₂, and 25(OH)D₃ levels were compared.ResultsWe examined the medical records of 48 patients who had been prescribed 50 000 IU vitamin D₂ in our clinic. Mean ± standard deviation baseline total 25(OH) D was 31.0 ± 10.6 ng/mL and rose to 48.3 ± 13.4 ng/mL after treatment (P <.001). 25(OH)D₂ increased from 4.2 ± 4.3 ng/mL to 34.6 ± 12.3 ng/mL after treatment (P <.001), for an average of 158 days (range, 35-735 days). Serum 25(OH)D3 decreased from 26.8 ± 10.8 ng/mL to 13.7 ± 7.9 ng/mL (P <.001).ConclusionsFifty thousand IU vitamin D₂ repletion and maintenance therapy substantially increases total 25(OH)D and 25(OH)D2 despite a decrease in serum 25(OH)D3. This treatment program is an appropriate and effective strategy to treat and prevent vitamin D deficiency.(Endocr Pract. 2012;18:399-402)     

Urinary Calcium Excretion in Primary Hyperparathyroidism: Relationship to 25-Hydroxyvitamin D Status

ObjectiveTo determine the prevalence of vitamin D deficiency in patients with primary hyperparathyroidism (PHPT) and evaluate the relationship between urinary calcium excretion and serum 25-hydroxyvitamin D (25-OH-D) levels in patients with PHPT.MethodsWe present a case report and a review of the medical records of patients with PHPT. Of 75 patients with PHPT substantiated by hypercalcemia and increased levels of intact parathyroid hormone (iPTH), 35 were identified with laboratory evaluation of vitamin D levels and 24-hour urinary calcium excretion. These study subjects were stratified as 25-OH-D deficient, insufficient, or replete (on the basis of serum values of < 15, 15 to 25, or > 25 ng/mL, respectively). Total 24-hour urinary calcium excretion and the fractional excretion of calcium (FECa) were analyzed as a function of 25-OH-D status.ResultsOf the 35 study subjects, 14 (40%) and 13 (37%) had 25-OH-D deficiency or insufficiency, respectively. Those patients with a 25-OH-D level < 15 ng/mL had higher serum iPTH concentrations as well as lower urinary calcium excretion and FECa. No significant correlations were found, however, between 25-OH-D status and iPTH concentrations (r = -0.21; P = 0.23), total 24-hour urinary calcium excretion (r = 0.07; P = 0.7), or FECa (r = 0.04; P = 0.8).ConclusionVitamin D deficiency (25-OH-D levels < 15 ng/mL) was common in our population of patients with PHPT. Urinary calcium excretion was not significantly altered by 25-OH-D deficiency in patients with newly recognized PHPT. Measurements of total urinary calcium excretion and FECa can be reliably used to rule out familial benign hypocalciuric hypercalcemia in the initial evaluation of PHPT, regardless of 25-OH-D status. Determining 25-OH-D concentrations best assesses the vitamin D status. (Endocr Pract. 2005;11:37-42)     

Associations between Vascular Health Indices and Serum Total,Free and Bioavailable 25-Hydroxyvitamin D in Adolescents

Objective

The role of vitamin D in cardiovascular health remains debated as results have been inconsistent. Previous studies have not considered the bioavailability of 25-hydroxy vitamin D [25(OH)D]. Objectives of our study were to investigate the association between serum concentrations of total, free and bioavailable 25(OH)D and independent predictors of cardiovascular risk such as flow mediated dilatation (FMD) and augmentation index (AIx).

Design

This cross-sectional study included 47 post-menarchal, adolescent females [31 African American (AA) and 16 European American (EA)].

Methods

AIx was standardized to a heart rate of 75 beats/min (AIx75). Free and bioavailable 25(OH)D concentrations were calculated from standard formulas.

Results and Conclusions

Mean age of the participants was 15.8±1.4 years and mean body mass index was 23.1±4.0 kg/m². Serum total 25(OH)D was not associated with FMD, but was positively associated with AIx75 in the adjusted model (rho = 0.4, P = 0.03). AIx75 was positively associated with bioavailable 25(OH)D (rho = 0.4, P = 0.004) and free 25(OH)D (rho = 0.4, P = 0.009) and the associations persisted after adjusting for covariates. In race-specific analyses, total, free and bioavailable 25(OH)D were strongly positively associated with AIx75 in AA (rho = 0.5, 0.4, 0.4, respectively), which persisted even after adjusting for covariates. Whereas in EA there was an inverse association between total 25(OH)D and AIx75 in EA (rho = −0.6), which attenuated after adjusting for covariates.

Conclusion

Circulating total, free and bioavailable 25(OH)D were associated with arterial stiffness in adolescent girls, and these associations were race dependent. Notwithstanding, the implications of associations between vascular function indices and 25(OH)D remains unclear.     

Trabecular Bone Score in Patients with Normocalcemic Hyperparathyroidism

Objective: The effects of normocalcemic hyperparathyroidism (NHPT) on bone remain unclear. The objective of this study was to evaluate differences in the trabecular bone score (TBS) of NHPT patients and asymptomatic hypercalcemic hyperparathyroidism (HHPT) patients.Methods: We performed a prospective study that enrolled consecutive patients with asymptomatic hyperparathyroidism (NHPT and HHPT) with a follow-up ≥1 year at the University Hospital of Valladolid, Spain. Metabolic phosphocalcium plasma and urine parameters were evaluated in ≥2 determinations during follow-up to classify patients as NHPT patients or asymptomatic HHPT patients. A control group was enrolled during the same period. TBS and bone mineral density (BMD) were evaluated.Results: Thirty-nine patients with asymptomatic HPT (24 with NHPT and 15 with HHPT) and 24 controls were recruited. NHPT patients and HHPT patients had a similar mean age, vitamin D level, TBS, and areal BMD (all sites). Compared to controls, symptomatic HPT patients had significantly higher parathyroid hormone (PTH) and calcium levels and significantly lower TBS and areal BMD at all sites (all P<.05). A significant negative relationship between TBS and PTH was found in asymptomatic HPT patients (r = -0.320, P = .043), which remained significant after adjustment for age, sex, and body mass index.Conclusion: There was no difference in the TBS between NHPT and HHPT patients. However, there was a reduction in the TBS of patients with asymptomatic HPT that was related to PTH levels but had no repercussion on bone mass. Higher levels of PTH seem to be responsible for this alteration in microarchitecture texture.Abbreviations:aBMD = areal bone mineral densityBMD = bone mineral densityBMI = body mass indexDXA = dual-energy X-ray absorptiometryHHPT = hypercalcemic hyperparathyroidismHPT = hyperparathyroidismHR-MRI = high-resolution magnetic resonanceHR-pQcT = high-resolution peripheral quantitative computed tomographyNHPT = normocalcemic hyper-parathyroidismPTH = parathyroid hormoneTBS = trabecular bone score25vitD = 25-hydroxyvitamin D     

25-Hydroxyvitamin D Levels and Acute Cellular Rejection in Liver Transplant Patients

ObjectiveTo investigate the association between 25-hydroxyvitamin D [25(OH)D] levels prior to liver transplantation (LT) and the development of acute cellular rejection (ACR) within the first year post LT.MethodsThis retrospective study included 275 consecutive LTs performed in 262 patients at Mayo Clinic in Jacksonville, Florida over 13 months. A total of 149 patients met the inclusion criteria. The correlations between 25(OH)D levels and the development, severity, and number of biopsy-proven ACR episodes were assessed.ResultsThe prevalence of 25(OH)D levels <30 ng/ mL was 92%. No association was found between pre LT 25(OH)D levels and the diagnosis of ACR (P = .61). Mean ± SD pre LT 25(OH)D levels were 16.1 ± 6.8 ng/mL for 48 subjects with no rejection, 16.1 ± 8.2 ng/mL for those with a mild first episode of ACR (n = 58), and 18.4 ± 12.4 ng/ mL for those who experienced a moderate/severe first ACR (n = 39). However, in a subgroup analysis of patients with 25(OH)D levels <30 ng/mL, there was a statistically significant negative correlation (P = .0252) between 25(OH) D level and the ACR rate.ConclusionVitamin D insufficiency and deficiency prior to LT was prevalent in our cohort. There was no statistically significant association between low 25(OH)D levels and the diagnosis or severity of ACR or the number of rejection episodes within the first year post LT. However, there was a negative correlation between 25(OH)D levels below 30 ng/mL and the rate of ACR within 1 year post LT. (Endocr Pract. 2014;20:769-774)     

Serum Levels of 25-Hydroxyvitamin D and Functional Outcome among Postmenopausal Women with Hip Fracture

Objective

The main objective of the current study was to assess the distribution and its prognostic value of serum 25-hydroxyvitamin D (25[OH] D) levels assessed at admission in Chinese postmenopausal women with hip fracture.

Methods

From January 1, 2012 to December 31, 2013, all postmenopausal women with first-ever hip fracture were recruited to participate in the study. Serum 25[OH] D levels were measured at admission. The functional evaluation at the time of discharge was performed by the Barthel Index (BI). The prognostic value of 25[OH] D to predict the functional outcome within discharge was analyzed by logistic regression analysis, after adjusting for the possible confounders.

Results

In our study, 261 patients were included and assessed. In the 76 patients with an unfavorable functional outcome, serum 25(OH) D levels were lower compared with those in patients with a favorable outcome [11.8(IQR, 9.9–16.1)ng/ml; 16.8(IQR, 13.6–21.4)ng/ml, respectively; P<0.0001]. In multivariate analysis, there was an increased risk of unfavorable outcome associated with serum 25(OH) D levels ≤ 20ng/ml (OR 5.24, 95%CI: 3.11–8.15; P<0.0001) after adjusting for possible confounders.

Conclusions

Our data support an association between serum 25[OH] D levels and prognosis in Chinese postmenopausal women with hip fracture.     

Seasonal Genetic Influence on Serum 25-Hydroxyvitamin D Levels: A Twin Study

Background

Although environmental factors, mainly nutrition and UV-B radiation, have been considered major determinants of vitamin D status, they have only explained a modest proportion of the variation in serum 25-hydroxyvitamin D. We aimed to study the seasonal impact of genetic factors on serum 25-hydroxyvitamin D concentrations.

Methodology/Principal findings

204 same-sex twins, aged 39–85 years and living at northern latitude 60°, were recruited from the Swedish Twin Registry. Serum 25-hydroxyvitamin D was analysed by high-pressure liquid chromatography and mass spectrometry. Genetic modelling techniques estimated the relative contributions of genetic, shared and individual-specific environmental factors to the variation in serum vitamin D. The average serum 25-hydroxyvitamin D concentration was 84.8 nmol/l (95% CI 81.0–88.6) but the seasonal variation was substantial, with 24.2 nmol/l (95% CI 16.3–32.2) lower values during the winter as compared to the summer season. Half of the variability in 25-hydroxyvitamin D during the summer season was attributed to genetic factors. In contrast, the winter season variation was largely attributable to shared environmental influences (72%; 95% CI 48–86%), i.e., solar altitude. Individual-specific environmental influences were found to explain one fourth of the variation in serum 25-hydroxyvitamin D independent of season.

Conclusions/Significance

There exists a moderate genetic impact on serum vitamin D status during the summer season, probably through the skin synthesis of vitamin D. Further studies are warranted to identify the genes impacting on vitamin D status.     

Low Serum 25-Hydroxyvitamin D Concentrations Are Associated with Increased Risk for Melanoma and Unfavourable Prognosis

Background

Low vitamin D status (serum 25(OH)D concentration) is associated with increased incidence and unfavourable outcome of various types of cancer. However, there are limited data on influence of serum 25(OH)D on risk and prognosis of malignant melanoma.

Methods

Basal serum 25(OH)D concentrations were retrospectively analyzed in a cohort of melanoma patients (n = 324) and healthy controls (n = 141). We tested the hypothesis that serum 25(OH)D concentrations are predictive of melanoma risk, thickness of primary melanomas, and overall survival (OS).

Results

Median serum 25(OH)D concentrations were significantly lower (p = 0.004) in melanoma patients (median = 13.6 ng/ml) as compared to controls (median = 15.6 ng/ml). Primary tumors of patients with low serum 25(OH)D concentrations (<10 ng/ml) had significantly (p = 0.006) greater Breslow thickness (median: 1.9 mm) as compared to patients with higher levels (>20 ng/ml; median: 1.00 mm). Patients with 25(OH)D serum concentrations in the lowest quartile had inferior overall survival (median: 80 months) comparing with the highest quartile (median: 195 months; p = 0.049).

Conclusions

Our data support the concept that serum 25(OH)D concentrations are associated with risk and prognosis of melanoma. Whether normalizing serum 25(OH)D concentrations in these patients improves outcomes will require testing in future clinical trials.     

Association between 25-Hydroxyvitamin D and Intact Parathyroid Hormone Levels Across Latitude among Adults with African Ancestry

Objective: To compare levels of 25-hydroxyvitamin D (25[OH]D) associated with a plateauing of intact parathyroid (iPTH) across latitudes among adults with African ancestry.Methods: This study included approximately 500 adults of African ancestry ages 25 to 45 years living in 4 sites: Chicago, Illinois (41°N), Jamaica (17°N), Ghana (6°N), and South Africa (34°S). Multivariate linear regression models, a nonlinear logistic growth curve model, and piecewise linear models with a single knot were fitted to estimate the 25[OH]D level associated with a plateauing of iPTH with adjustment for covariates. Goodness of fit was compared using computer intensive permutation tests.Results: Mean age was 34.7 (SD 6.2) years, and 46.5% were male. Within each site, the percentage of participants with an iPTH level ≥65 pg/mL was higher among females versus males and was most frequent among South African females (17.1%) and lowest among Jamaican males (0.6%). Goodness of fit tests supported linear regression as the preferred model for the association between iPTH and 25[OH]D in the 4 sites with no 25[OH]D level associated with iPTH plateauing in any site. The slope of the association between 25[OH]D and iPTH differed by latitude; it was strongest in the U.S. (β = -0.81; 95% confidence interval [CI] = -1.03, -0.59), and weakest in Jamaica (β = -0.45; 95% CI -0.71, -0.18) with covariate adjustment, but differences in slopes were small.Conclusion: The association between 25[OH]D and iPTH appears linear among adults with African ancestry regardless of latitude within a range of 25[OH]D levels between 10 and 60 ng/mL.Abbreviations:BMI = body mass indexCI = confidence intervaleGFR = estimated glomerular filtration rateiPTH = intact parathryoid hormone25[OH]D = 25-hydroxyvitamin D     

Prognostic Value of Serum 25-Hydroxyvitamin D in Patients with Stroke

We aimed to evaluate the association between 25-hydroxyvitamin D [25(OH) D] levels and both clinical severity at admission and outcome at discharge in patients with acute ischemic stroke (AIS). From June 2012 to October 2013, consecutive first-ever AIS patients admitted to the Department of Emergency of The Fourth Affiliated Hospital of Harbin Medical University, China were identified. Clinical information was collected. Serum 25(OH) D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome was evaluated at discharge using the modified Rankin scale (m-Rankin). Multivariate analyses were performed using logistic regression models. During the study period, 326 patients were diagnosed as AIS and were included in the analysis. Serum 25(OH) D levels reduced with increasing severity of stroke as defined by the NIHSS score. There was a negative correlation between levels of 25(OH) D and the NIHSS (r = ? 0.389, P = 0.000). In multivariate analyses, serum 25(OH) D level was an independent prognostic marker of discharge favorable functional outcome and survival [odds ratio 3.96 (2.85–7.87) and 3.36 (2.12–7.08), respectively, P = 0.000 for both, adjusted for NHISS, other predictors and vascular risk factors] in patients with AIS. Serum 25(OH) D levels are a predictor of both severity at admission and favorable functional outcome in patients with AIS. Additional research is needed on vitamin D supplementation to improve the outcome of post-stroke patients.     

Standardization of Misleading Immunoassay Based 25-Hydroxyvitamin D Levels with Liquid Chromatography Tandem-Mass Spectrometry in a Large Cohort Study

Background

The interest in vitamin D measurement has strongly increased in recent years. The best indicator for circulating vitamin D levels is 25-hydroxy-vitamin D (25(OH)D) which is often measured by different immunoassays. We demonstrate problems in comparability of measures by different immunoassays and the need for standardization in the context of a large population-based cohort study.

Methods

25(OH)D was measured with the immunoassays Diasorin Liaison in 2006 in 5,386 women and in the context of another project with IDS-iSYS in 4,199 men in 2009–2010 (when the Diasorin Liaison was no longer available in the version utilized in 2006). Standardization was performed by re-measuring of 25(OH)D levels in 97 men and 97 women with liquid chromatography tandem-mass spectrometry (LC-MS/MS) to obtain linear regression conversion equations.

Results

Applying a 30 nmol/L cut-off value for vitamin D deficiency would have resulted in 48.3% of women and 12.1% of men with vitamin D deficiency ahead of standardization. The large gender difference was strongly attenuated after standardization of the assays with only 15.7% of women and 14.3% of men with vitamin D deficiency. Standardization on average increased the 25(OH)D levels by 10.3 nmol/L in women and decreased 25(OH)D levels by 2.9 nmol/L in men.

Conclusion

The standardization with LC-MS/MS revealed that much of the observed gender difference was only assay-driven and the extremely high proportion of 48.3% vitamin D deficient women proved to be an exaggeration of the old version of the Diasorin-Liaison immunoassay. Standardization of 25(OH)D immunoassay results by LC-MS/MS is recommended to improve their accuracy and comparability, provided the LC-MS/MS method itself is adequately validated and standardized.     

Serum 25-Hydroxyvitamin D Levels and Dry Eye Syndrome: Differential Effects of Vitamin D on Ocular Diseases

Purpose

To investigate associations between serum 25-hydroxyvitamin D levels and dry eye syndrome (DES), and to evaluate the differential effect of vitamin D on ocular diseases including age-related macular disease (AMD), diabetic retinopathy (DR), cataract, and DES.

Methods

A total of 16,396 participants aged >19 years were randomly selected from the Korean National Health and Nutrition Examination Survey. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. DES was defined by a history of clinical diagnosis of dry eyes by a physician. The association between vitamin D and DES was compared to the associations between vitamin D and AMD, DR, cataract, and DES from our previous studies.

Results

The odds of DES non-significantly decreased as the quintiles of serum 25-hydroxyvitamin D levels increased (quintile 5 versus 1, OR = 0.85, 95%CI: 0.55–1.30, P for trend = 0.076) after adjusting for potential confounders including age, sex, hypertension, diabetes, smoking status, and sunlight exposure times. The relative odds of DES (OR = 0.70, 95% CI: 0.30–1.64) and cataract (OR = 0.76, 95% CI: 0.59–0.99) were relatively high, while those of DR (OR = 0.37, 95% CI: 0.18–0.76) and late AMD (OR = 0.32, 95% CI: 0.12–0.81) were lower in men.

Conclusions

The present study does not support an association between serum 25-hydroxyvitamin D levels and DES. The preventive effect of serum 25-hydroxyvitamin D may be more effective for DR and late AMD than it is for cataract and DES.     

Inverse Association between High Blood 25-Hydroxyvitamin D Levels and Diabetic Retinopathy in a Representative Korean Population

Purpose

To investigate the association between 25-hydroxyvitamin D and diabetic retinopathy (DR).

Methods

A population-based cross-sectional study using a nation-wide, systemically stratified, multistage, clustered sampling method included a total of 18,363 subjects aged ≥40 years who participated in the Korean National Health and Nutrition Examination Survey during 2008–2012. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. Seven standard retinal fundus photographs were obtained from both eyes after pupil dilatation. DR was graded according to the modified Airlie House classification system.

Results

The blood 25-hydroxyvitamin D levels were 19.2 ng/mL in men and 17.9 ng/mL in women. After adjusting for potential confounders, including age, sex, diabetes duration, hemoglobin A1c levels, and hypertension, the odds ratios (OR) for any DR and proliferative DR among men decreased significantly in the highest blood 25-hydroxyvitamin D level quintile relative to the lowest quintile (OR, 0.37; 95% confidence interval [CI], 0.18–0.76; P for trend  = 0.004 and OR, 0.15; 95% CI, 0.03–0.83; P for trend  = 0.043).

Conclusions

This study provides the first epidemiologic findings of the inverse relationships of blood 25-hydroxyvitamin D levels with any DR and proliferative DR only in men. Considering anti-angiogenic and anti-fibrotic action of vitamin D, further studies including longitudinal and interventional analysis are warranted.     

Low Serum Magnesium Levels in Elderly Subjects with Metabolic Syndrome

This study aims at determining possible association between serum magnesium (Mg) concentrations and metabolic syndrome (MetS) in elderly subjects. Subjects were 137 men and women aged 60 to 90 years, selected from among participants of the Tehran Lipid and Glucose Study after excluding those taking medications for hypertension and dyslipidemia. Serum Mg levels were measured by atomic absorption spectrometry and MetS was defined according to ATP III criteria. The overall prevalence of MetS was 43.8%. Among MetS components, only plasma glucose showed a negative correlation with serum Mg concentrations (r = −0.194, p = 0.024). Subjects with MetS had significantly lower serum Mg concentrations compared with non-MetS ones (2.09 ± 0.03 vs. 2.18 ± 0.03 mg/dL, p = 0.033) even after adjustments with MetS components except for hyperglycemia (2.04 ± 0.06 vs. 2.20 ± 0.05 mg/dL, p = 0.011). However, after adjustment for hyperglycemia per se or along with the other MetS components, the significant difference between serum Mg levels in subjects with and without MetS disappeared. In conclusion, serum Mg level is diminished in elderly subjects with MetS, and hyperglycemia may play dominant role in this decrease; however, the results do not clarify whether the low serum Mg level is a consequence of hyperglycemia or is a risk factor contributing to its development.     

Cardio-Metabolic Disease Risks and Their Associations with Circulating 25-Hydroxyvitamin D and Omega-3 Levels in South Asian and White Canadians

Objectives

This study compared cardio-metabolic disease risk factors and their associations with serum vitamin D and omega-3 status in South Asian (SAC) and White Canadians (WC) living in Canada’s capital region.

Methods

Fasting blood samples were taken from 235 SAC and 279 WC aged 20 to 79 years in Ottawa, and 22 risk factors were measured.

Results

SAC men and women had significantly higher fasting glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), apolipoprotein B (ApoB), ratios of total (TC) to HDL cholesterol (HDLC) and ApoB to ApoA1, leptin, E-selectin, P-selectin, ICAM-1 and omega-3 (p < 0.05), but lower HDLC, ApoA1, vitamin D levels than WC (p < 0.05). SAC women had higher CRP and VEGF than WC women. Adequate (50–74.9 nmol/L) or optimal (≥ 75 nmol/L) levels of 25(OH)D were associated with lower BMI, glucose, insulin, HOMA-IR, TG, TC, low density lipoprotein cholesterol (LDLC), ApoB/ApoA1 ratio, CRP, leptin, and higher HDLC, ApoA1, omega-3 index, L-selectin levels in WC, but not in SAC. Intermediate (>4%-<8%) or high (≥ 8%) levels of omega-3 indices were related to lower E-selectin, P-selectin, ICAM-1 and higher HDLC, 25(OH)D levels in WC, but not in SAC. The BMIs of ≤ 25 kg/m² were related to lower LDLC, ApoB, VEGF, creatinine and higher 25(OH)D in WC, but not in SAC.

Conclusions

The associations of vitamin D, omega-3 status, BMI and risk factors were more profound in the WC than SAC. Compared to WC, vitamin D status and omega-3 index may not be good predictive risk factors for the prevalence of CVD and diabetes in SAC.     

Cerebrospinal Fluid (CSF) 25-Hydroxyvitamin D Concentration and CSF Acetylcholinesterase Activity Are Reduced in Patients with Alzheimer's Disease

Background

Little is known of vitamin D concentration in cerebrospinal fluid (CSF) in Alzheimer´s disease (AD) and its relation with CSF acetylcholinesterase (AChE) activity, a marker of cholinergic function.

Methods

A cross-sectional study of 52 consecutive patients under primary evaluation of cognitive impairment and 17 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n = 28), other dementias (n = 12), and stable MCI (SMCI, n = 12). We determined serum and CSF concentrations of calcium, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), and CSF activities of AChE and butyrylcholinesterase (BuChE).

Findings

CSF 25OHD level was reduced in AD patients (P < 0.05), and CSF AChE activity was decreased both in patients with AD (P < 0.05) and other dementias (P < 0.01) compared to healthy controls. None of the measured variables differed between BuChE K-variant genotypes whereas the participants that were homozygous in terms of the apolipoprotein E (APOE) ε4 allele had decreased CSF AChE activity compared to subjects lacking the APOE ε4 allele (P = 0.01). In AD patients (n=28), CSF AChE activity correlated positively with CSF levels of total tau (T-tau) (r = 0.44, P < 0.05) and phosphorylated tau protein (P-tau) (r = 0.50, P < 0.01), but CSF activities of AChE or BuChE did not correlate with serum or CSF levels of 25OHD.

Conclusions

In this pilot study, both CSF 25OHD level and CSF AChE activity were reduced in AD patients. However, the lack of correlations between 25OHD levels and CSF activities of AChE or BuChE might suggest different mechanisms of action, which could have implications for treatment trials.