Vitamin D deficiency--prognostic marker or mortality risk factor in end stage renal disease patients with diabetes mellitus treated with hemodialysis--a prospective multicenter study. PLoS One. 2015;10:e0126586. [PMID: 25965403 PMCID: PMC4428845 DOI: 10.1371/journal.pone.0126586]

Progression of diabetic nephropathy and vitamin D serum levels: A pooled analysis of 7722 patients

BACKGROUND AND AIM

Low serum Vitamin D levels have been associated with diabetic nephropathy (DN). Our study aimed to analyse the serum levels of vitamin D in patients suffering from DN and the subsequent changes in serum vitamin D levels as the disease progresses.

METHODS

PubMed, Embase, SCOPUS and Web of Science were searched using keywords such as '25 hydroxyvitamin D' and 'diabetic nephropathy'. We included observational studies that reported the association between the serum 25 hydroxy vitamin D levels and diabetic nephropathy without restriction to age, gender, and location. R Version 4.1.2 was used to perform the meta-analysis. The continuous outcomes were represented as mean difference (MD) and standard deviation (SD) and dichotomous outcomes as risk ratios (RR) with their 95% confidence interval (CI).

RESULTS

Twenty-three studies were included in our analysis with 7722 patients. Our analysis revealed that vitamin D was significantly lower in diabetic patients with nephropathy than those without nephropathy (MD: -4.32, 95% CI: 7.91-0.74, p-value = .0228). On comparing diabetic patients suffering from normoalbuminuria, microalbuminuria, or macroalbuminuria, we found a significant difference in serum vitamin D levels across different groups. Normoalbuminuria versus microalbuminuria showed a MD of -1.69 (95% CI: -2.28 to -1.10, p-value = .0002), while microalbuminuria versus macroalbuminuria showed a MD of (3.75, 95% CI: 1.43-6.06, p-value = .0058), proving that serum vitamin D levels keep declining as the disease progresses. Notwithstanding, we detected an insignificant association between Grade 4 and Grade 5 DN (MD: 2.29, 95% CI: -2.69-7.28, p-value = .1862).

CONCLUSION

Serum Vitamin D levels are lower among DN patients and keep declining as the disease progresses, suggesting its potential benefit as a prognostic marker. However, on reaching the macroalbuminuria stage (Grades 4 and 5), vitamin D is no longer a discriminating factor.

Serum 25(OH)D Concentration, Vitamin D Supplementation, and Risk of Cardiovascular Disease and Mortality in Patients with Type 2 Diabetes or Prediabetes: a Systematic Review and Dose-Response Meta-Analysis

BACKGROUND

Evidence is uncertain about the association between serum 25-hydroxyvitamin D (25(OH)D) concentration and health outcomes in people with type 2 diabetes.

OBJECTIVES

We aimed to assess the association between vitamin D status and all-cause mortality and cardiovascular disease in people with type 2 diabetes.

METHODS

We did a systematic search in PubMed, Scopus, CENTRAL, and Web of Science until May 2022. We selected 1) cohort studies investigating the association between serum 25(OH)D concentration and mortality or cardiovascular disease in people with type 2 diabetes or prediabetes and 2) randomized trials of vitamin D supplementation in these patients. We used random-effects pairwise meta-analyses to calculate summary relative risks (RRs) and 95% confidence intervals (CI).

RESULTS

21 cohort studies and 6 randomized trials were included. Compared with sufficient vitamin D status (≥50 nmol/L), the RR of all-cause mortality was 1.36 (95% CI: 1.23, 1.49; n = 11 studies, GRADE = moderate) for vitamin D insufficiency (25 to <50 nmol/L), and 1.58 (1.33, 1.83; n = 16, GRADE = moderate) for deficiency (<25 nmol/L). Similar findings were observed for cardiovascular mortality and morbidity but not for cancer mortality. The certainty of evidence ranged from very low to moderate. Dose-response meta-analyses indicated nonlinear associations, with the lowest risk at 25(OH)D ∼60 nmol/L for all-cause and cardiovascular mortality. Supplementation with vitamin D did not reduce the risk of all-cause mortality (RR: 0.96, 95% CI: 0.79, 1.16; risk difference per 1000 patients: 3 fewer, 95% CI: 16 fewer, 12 more; n = 6 trials with 7316 participants; GRADE = low) or the risk of cardiovascular mortality and morbidity (very low- to low-certainty evidence).

CONCLUSIONS

Vitamin D deficiency and insufficiency are associated with a higher risk of all-cause and cardiovascular mortality in patients with type 2 diabetes or prediabetes. Vitamin D deficiency should be corrected in patients with type 2 diabetes to reach normal serum 25(OH)D concentrations, preferably 60 nmol/L.

SYSTEMATIC REVIEW REGISTRATION

This systemic review was registered at PROSPERO as CRD42022326429 (=https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=326429).

Does Native Vitamin D Supplementation Have Pleiotropic Effects in Patients with End-Stage Kidney Disease? A Systematic Review of Randomized Trials

Vitamin D has been shown to have multiple pleiotropic effects beyond bone and mineral metabolism, with purported roles in cardiovascular disease, cancer, and host immunity. Vitamin D deficiency is common in patients with end-stage kidney disease (ESKD); however, current clinical practice has favored the use of the active hormone. Whether vitamin D deficiency should be corrected in patients with ESKD remains unclear, as few randomized trials have been conducted. In this systematic review, we summarize the current evidence examining whether vitamin D supplementation improves outcomes, beyond mineral metabolism, in patients with ESKD. Data from randomized controlled trials of adults with ESKD were obtained by searching Ovid MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and the Web of Science Core Collection from inception to February 2023. Twenty-three trials composed of 2489 participants were identified for inclusion. Data were synthesized by two independent reviewers and summarized in tables organized by outcome. Outcomes included measures of mortality, cardiovascular disease, inflammation, muscle strength/function, nutrition, patient well-being, and outcomes specific to ESKD including erythropoietin usage, pruritus, and dialysis access maturation. The Cochrane risk of Bias Tool (RoB 2, 2019) was used to assess study quality. Overall, our findings indicate a minimal and varied benefit of native vitamin D supplementation. From the largest studies included, we determine that vitamin D has no demonstrated effect on patient-reported measures of well-being or utilization of erythropoietin, nor does it change levels of the inflammation biomarker C-reactive protein. Included trials were heterogeneous with regards to outcomes, and the majority studied small participant populations with a relatively short follow-up. We conclude that vitamin D supplementation corrects vitamin D deficiency and is safe and well-tolerated in humans with ESKD. However, it is not clear from clinical trials conducted to date that a causal pathway exists between 25(OH)D and pleiotropic effects that is responsive to vitamin D treatment.

Vitamin D deficiency contributes to the diabetic kidney disease progression via increase ZEB1/ZEB2 expressions

BACKGROUND

Diabetic kidney disease (DKD) remains one of the main causes of end-stage renal disease (ESRD) and mortality in diabetic patients worldwide. Vitamin D deficiency (VitDD) is one of the main consequences of different chronic kidney disease (CKD) types and is associated with rapid progression to ESRD. Nevertheless, the mechanisms that lead to this process are poorly understood. This study aimed to characterize a model of diabetic nephropathy progression in VitDD and the epithelial-mesenchymal-transition (EMT) role in these processes.

METHODS

Wistar Hannover rats received a diet with or without VitD before type 1 diabetes (T1D) induction. After this procedure, the rats were accompanied for 12 and 24 weeks after T1D induction and the renal function, structure, cell transdifferentiating markers and zinc finger e-box binding homeobox 1/2 (ZEB1/ZEB2) contribution to kidney damage were evaluated during the DKD progression.

RESULTS

The results showed an increase in glomerular tuft, mesangial and interstitial relative areas and renal function impairment in VitD-deficient diabetic rats compared to diabetic rats that received a VitD-containing diet. These alterations can be associated with increased expression of EMT markers, ZEB1 gene expression, ZEB2 protein expression and TGF-β1 urinary excretion. Decreased miR-200b expression, an important post-transcriptional regulator of ZEB1 and ZEB2 was also observed.

CONCLUSION

Our data demonstrated that VitD deficiency contributes to the rapid development and progression of DKD in diabetic rats induced by increase ZEB1/ZEB2 expressions and miR-200b downregulation.

Associations of Nutritional, Environmental, and Metabolic Biomarkers with Diabetes-Related Mortality in U.S. Adults: The Third National Health and Nutrition Examination Surveys between 1988-1994 and 2016

Background: Nutritional, environmental, and metabolic status may play a role in affecting the progression and prognosis of type 2 diabetes. However, results in identifying prognostic biomarkers among diabetic patients have been inconsistent and inconclusive. We aimed to evaluate the associations of nutritional, environmental, and metabolic status with disease progression and prognosis among diabetic patients. Methods: In a nationally representative sample in the NHANES III (The Third National Health and Nutrition Examination Survey, 1988−1994), we analyzed available data on 44 biomarkers among 2113 diabetic patients aged 20 to 90 years (mean age: 58.2 years) with mortality data followed up through 2016. A panel of 44 biomarkers from blood and urine specimens available from NHANES III were included in this study and the main outcomes as well as the measures are mortalities from all-causes. We performed weighted logistic regression analyses after controlling potential confounders. To assess incremental prognostic values of promising biomarkers beyond traditional risk factors, we compared c-statistics of the adjusted models with and without biomarkers, separately. Results: In total, 1387 (65.2%) deaths were documented between 1988 and 2016. We observed an increased risk of all-cause mortality associated with higher levels of serum C-reactive protein (p for trend = 0.0004), thyroid stimulating hormone (p for trend = 0.04), lactate dehydrogenase (p for trend = 0.02), gamma glutamyl transferase (p for trend = 0.02), and plasma fibrinogen (p for trend = 0.03), and urine albumin (p for trend < 0.0001). In contrast, higher levels of serum sodium (p for trend = 0.005), alpha carotene (p for trend = 0.006), and albumin (p for trend = 0.005) were associated with a decreased risk of all-cause mortality. In addition, these significant associations were not modified by age, sex, or race. Inclusion of thyroid stimulating hormone (p = 0.03), fibrinogen (p = 0.01), and urine albumin (p < 0.0001), separately, modestly improved the discriminatory ability for predicting all-cause mortality among diabetic patients. Conclusions: Our nationwide study findings provide strong evidence that some nutritional, environmental, and metabolic biomarkers were significant predictors of all-cause mortality among diabetic patients and may have potential clinical value for improving stratification of mortality risk.

Hypovitaminosis D and cardiovascular outcomes: A systematic review and meta-analysis

•

Vitamin D deficiency can not only affect bones but have association with cardiovascular effects.

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The likelihood of unfavorable cardiovascular outcomes, especially major adverse cardiovascular event (MACE), new MI, and all-cause mortality among deficient vitamin D patient is poorly understood.

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This is a first and most comprehensive meta-analysis with the largest sample size thus far comparing vitamin D levels in terms of cardiovascular outcomes.

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High risk patients need to monitor vitamins level and implement vitamins supplementation to avoid adverse outcomes especially elder females.

Background

Methods

Results

Conclusions

Association of Serum 25-Hydroxyvitamin D With Cardiovascular Outcomes and All-Cause Mortality in Individuals With Prediabetes and Diabetes: Results From the UK Biobank Prospective Cohort Study

OBJECTIVE

To examine the associations of circulating 25-hydroxyvitamin D (25[OH]D) concentrations with cardiovascular disease (CVD) and all-cause mortality in individuals with prediabetes and diabetes from the large population-based UK Biobank cohort study.

RESEARCH DESIGN AND METHODS

A total of 67,789 individuals diagnosed with prediabetes and 24,311 with diabetes who had no CVD or cancer at baseline were included in the current study. Serum 25(OH)D concentrations were measured at baseline. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs for cardiovascular outcomes and mortality after 10-14 years.

RESULTS

After multivariable adjustment, higher serum 25(OH)D levels were significantly and nonlinearly associated with lower risk of cardiovascular outcomes and all-cause mortality among participants with prediabetes and diabetes (all P nonlinearity < 0.05). Compared with those in the lowest category of 25(OH)D levels (<25 nmol/L), participants with prediabetes in the highest category of 25(OH)D levels (≥75 nmol/L) had a significant association with lower risk of cardiovascular events (HR 0.78; 95% CI 0.71-0.86), coronary heart disease (CHD) (HR 0.79; 95% CI 0.71-0.89), heart failure (HR 0.66; 95% CI 0.54-0.81), stroke (HR 0.75; 95% CI 0.61-0.93), CVD mortality (HR 0.43; 95% CI 0.32-0.59), and all-cause mortality (HR 0.66; 95% CI 0.58-0.75). Likewise, these associations with cardiovascular events, CHD, heart failure, CVD mortality, and all-cause mortality were observed among participants with diabetes, except for stroke.

CONCLUSIONS

These findings highlight the importance of monitoring and correcting vitamin D deficiency in the prevention of CVD and mortality among adults with prediabetes and diabetes.

The Association of Sleep Quality and Vitamin D Levels in Hemodialysis Patients

Background

To date, hemodialysis (HD) is the most common therapy for chronic kidney disease (CKD) patients. However, it causes different complications such as sleep disorders. Sleep regulation is connected to vitamin D; hence, its deficiency might influence the quality and duration of sleep. This study is aimed at evaluating the correlation of sleep quality and vitamin D levels in 80 HD patients.

Methods

This cross-sectional study was performed on 80 hemodialysis patients admitted to 29 Bahman hospitals in Tabriz, Iran. Before beginning of dialysis, serum 25 (OH) D levels were assessed among patients and the sleep patterns and sleep quality of patients were accurately calculated by the Pittsburgh sleep quality index (PSQI) standard questionnaire.

Results

Our results showed that 22 HD patients (27.5%) had severe sleep disorders. In addition, it was found that serum levels of vitamin D had significant correlation with sleep quality (r = −0.341, p = 0.002) in general, even after adjusting confounding factors such as calcium (Ca), phosphate (P), and parathyroid hormone (PTH) level. In poor sleepers (PSQI ≤ 5), a negative correlation was observed between the levels of vitamin D and PSQI score (r = −0.397, p = 0.004). PSQI scores in the normal range of PTH (r = −0.377, p = 0.006) and in >600 pg/ml of PTH (r = −0.675, p = 0.011) had a correlation with vitamin D levels. The level of vitamin D was the single independent predictor of sleep efficiency (β coefficient = −0.386, p = 0.001).

Conclusion

The present project reported that the positive effect of vitamin D is associated with sleep disorder in HD patients. In future studies, normal levels of Ca and P should be considered along with normal vitamin D levels among the included patients.

Association of serum vitamin D levels with chronic disease and mortality

Introduction

Introduction: whether hypovitaminosis D is an overarching cause of increased mortality or a prognostic marker of poor health has not been well elucidated. Objectives: we sought to determine the association of serum 25-hydroxyvitamin D [25-(OH)-D3] levels with the clinical biochemical parameters and mortality risk in chronic diseases. Methods: we reviewed the clinical charts and collected the clinical biochemical parameters of patients diagnosed with chronic conditions who had at least one 25-(OH)-D3 determination, with or without calcium and vitamin D supplementation, and who were selected using a cluster random sampling design (n = 1,705). The analysis was focused on metabolic disorders (type-2 diabetes mellitus [T2DM] and obesity), autoimmune disorders, and mortality. Multivariate logistic regression analyses were performed. Results: low 25-(OH)-D3 levels were reported in 1,433 (84.0%) patients, of which 774 (45.4%) had insufficiency (20-29 ng/mL) and 659 (38.6%) patients had deficiency (< 20 ng/mL). Lower 25-(OH)-D3 levels in T2DM patients were associated with higher glycosylated hemoglobin levels (p < 0.001). Patients with 25-(OH)-D3 levels < 12.5 ng/mL had a higher mortality risk than those with levels ≥ 12.5 ng/mL (HR: 3.339; 95% CI: 1.342-8.308). We observed lower 25-(OH)-D3 levels in patients with grade-III obesity (p = 0.01). We found a higher risk of 25-(OH)-D3 deficiency in rheumatoid arthritis, type-1 diabetes, and systemic lupus erythematosus (p = 0.032, p = 0.002, p = 0.049, respectively). Conclusions: we found a significant relationship between 25-(OH)-D3 levels and glycemic control, body mass index, autoimmune disease, and mortality risk. Nevertheless, whether hypovitaminosis D plays a causal role or is a consequence of chronic disease remains controversial.

Dietary supplements, vitamins and minerals as potential interventions against viruses: Perspectives for COVID-19

Abstract. The novel coronavirus (SARS-CoV-2) causing COVID-19 disease pandemic has infected millions of people and caused more than thousands of deaths in many countries across the world. The number of infected cases is increasing day by day. Unfortunately, we do not have a vaccine and specific treatment for it. Along with the protective measures, respiratory and/or circulatory supports and some antiviral and retroviral drugs have been used against SARS-CoV-2, but there are no more extensive studies proving their efficacy. In this study, the latest publications in the field have been reviewed, focusing on the modulatory effects on the immunity of some natural antiviral dietary supplements, vitamins and minerals. Findings suggest that several dietary supplements, including black seeds, garlic, ginger, cranberry, orange, omega-3 and -6 polyunsaturated fatty acids, vitamins (e.g., A, B vitamins, C, D, E), and minerals (e.g., Cu, Fe, Mg, Mn, Na, Se, Zn) have anti-viral effects. Many of them act against various species of respiratory viruses, including severe acute respiratory syndrome-related coronaviruses. Therefore, dietary supplements, including vitamins and minerals, probiotics as well as individual nutritional behaviour can be used as adjuvant therapy together with antiviral medicines in the management of COVID-19 disease.

Association between vitamin D levels and mortality in hemodialysis patients: a cohort study

Introduction: Low vitamin D levels are associated with mortality in hemodialysis (HD) patients; however, the serum vitamin D thresholds are unclear. This study aimed to identify the vitamin D level below which mortality increases in HD patients.Methods: A cohort of HD patients enrolled from January 2014 to January 2017 was evaluated. The variables were analyzed according to the season, namely, summer, winter, and annual average, mortality was the primary outcome. The patients were assigned to vitamin D quintiles, and multivariate Cox regression analysis adjusted for age, ethnicity, gender, body mass index (BMI), inhibitors of the renin-angiotensin system, statin, calcitriol, and antiplatelet drugs use, hemodialysis vintage, hypertension, diabetes mellitus, atherosclerotic disease, and C-reactive protein was performed.Results: There were studied 306 patients. Vitamin D levels of 18.0-23.6 ng/mL (hazard ratio [HR] = 4.30; 95% confidence interval [CI] 1.60-11.54, p = 0.004) and <18.0 ng/mL (HR = 3.83; 95% CI: 1.42-10.35, p = 0.008) in summer and vitamin D levels of 21.5-27.1 ng/mL (HR = 3.70; 95% CI: 1.50-9.11, p = 0.004) and ≤17.5 ng/mL (HR = 2.84; 95% CI: 1.13-7.13, p = 0.026) in winter were associated with mortality. The average annual values of vitamin D associated with all-cause mortality were <17.7 ng/dL (adjusted HR = 4.25, 95% CI: 1.57-11.48, p = 0.004), and between >17.7 ng/dL and ≤23.1 ng/dL (adjusted HR = 3.91, 95% CI: 1.47-10.42, p = 0.006).Conclusions: Annual average vitamin D levels <23.1 ng/mL were associated with higher all-cause mortality, regardless of the confounding variables evaluated.

Effects of parathyroid hormone and vitamin D supplementation on stroke among patients receiving peritoneal dialysis

BACKGROUND

Continuous ambulatory peritoneal dialysis (CAPD) patients have a high incidence of stroke and commonly have increased parathyroid hormone levels and vitamin D insufficiency. We seek to investigate the incidence of stroke and the role of parathyroid hormone and vitamin D supplementation in stroke risk among CAPD patients.

METHODS

This study employed a retrospective design. We enrolled a Chinese cohort of 980 CAPD patients who were routinely followed in our department. The demographic and clinical data were recorded at the time of initial CAPD and during follow-up. The included patients were separated into non-stroke and stroke groups. The effects of parathyroid hormone and vitamin D supplementation on stroke in CAPD patients was evaluated. The primary endpoint is defined as the first occurrence of stroke, and composite endpoint events are defined as death or switch to hemodialysis during follow-up.

RESULTS

A total of 757 eligible CAPD patients with a mean follow-up time of 54.7 (standard deviation, 33) months were included in the study. The median incidence of stroke among our CAPD patients was 18.9 (interquartile range, 15.7-22.1) per 1000 person-years. A significant nonlinear correlation between baseline iPTH and hazard of stroke (p-value of linear association = 0.2 and nonlinear association = 0.002) was observed in our univariate Cox regression analysis, and low baseline iPTH levels (≤150 pg/ml) were associated with an increased cumulative hazard of stroke. Multivariate Cox regression analysis indicated a significant interaction effect between age and iPTH after adjusting for other confounders. Vitamin D supplementation during follow-up was a predictive factor for stroke in our cohort.

CONCLUSIONS

CAPD patients suffered a high risk of stroke, and lower iPTH levels were significantly correlated with an increased risk of stroke. Nevertheless, vitamin D supplementation may reduce the risk of stroke in these patients.

Preoperative Vitamin D Concentration and Cardiac, Renal, and Infectious Morbidity after Noncardiac Surgery

BACKGROUND

Low 25-hydroxyvitamin D is associated with cardiovascular, renal, and infectious risks. Postsurgical patients are susceptible to similar complications, but whether vitamin D deficiency contributes to postoperative complications remains unclear. We tested whether low preoperative vitamin D is associated with cardiovascular events within 30 days after noncardiac surgery.

METHODS

We evaluated a subset of patients enrolled in the biobank substudy of the Vascular events In noncardiac Surgery patIents cOhort evaluatioN (VISION) study, who were at least 45 yr with at least an overnight hospitalization. Blood was collected preoperatively, and 25-hydroxyvitamin D was measured in stored samples. The primary outcome was the composite of cardiovascular events (death, myocardial injury, nonfatal cardiac arrest, stroke, congestive heart failure) within 30 postoperative days. Secondary outcomes were kidney injury and infectious complications.

RESULTS

A total of 3,851 participants were eligible for analysis. Preoperative 25-hydroxyvitamin D concentration was 70 ± 30 nmol/l, and 62% of patients were vitamin D deficient. Overall, 26 (0.7%) patients died, 41 (1.1%) had congestive heart failure or nonfatal cardiac arrest, 540 (14%) had myocardial injury, and 15 (0.4%) had strokes. Preoperative vitamin D concentration was not associated with the primary outcome (average relative effect odds ratio [95% CI]: 0.93 [0.85, 1.01] per 10 nmol/l increase in preoperative vitamin D, P = 0.095). However, it was associated with postoperative infection (average relative effect odds ratio [95% CI]: 0.94 [0.90, 0.98] per 10 nmol/l increase in preoperative vitamin D, P adjusted value = 0.005) and kidney function (estimated mean change in postoperative estimated glomerular filtration rate [95% CI]: 0.29 [0.11, 0.48] ml min 1.73 m per 10 nmol/l increase in preoperative vitamin D, P adjusted value = 0.004).

CONCLUSIONS

Preoperative vitamin D was not associated with a composite of postoperative 30-day cardiac outcomes. However, there was a significant association between vitamin D deficiency and a composite of infectious complications and decreased kidney function. While renal effects were not clinically meaningful, the effect of vitamin D supplementation on infectious complications requires further study.

Shear Wave Elastography in Diagnosing Secondary Hyperparathyroidism

This study evaluates the diagnostic value of two-dimensional shear wave elastography (2 D-SWE) technique in the evaluation of hyperplastic parathyroid glands in cases with secondary and tertiary hyperparathyroidism. A total of 59 patients (end-stage renal disease, under supplemental dialysis program) with visible parathyroid hyperplastic glands on ultrasound, confirmed by biochemical assay and scintigraphy, were enrolled; they were examined on grayscale ultrasound and 2 D shear wave elastography. We determined the elasticity index (EI) in the parathyroid gland, thyroid parenchyma and surrounding muscles, and the elasticity ratio of hyperplastic parathyroid glands compared to muscle, specifically sternocleidomastoid muscle. Patients presented fibrocystic bone disease with secondary hyperparathyroidism induced by end-stage chronic kidney disease; being on prolonged chronic dialysis therapy, they had positive sestamibi scintigraphy and high values of serum parathormone (1141.04 pg/mL). Nodules placed posterior to the thyroid capsule that were cystic, had a hypoechoic aspect, and were homogenous with an independent afferent artery were found. Mean EI in the parathyroid gland was 7.83 kPa, the median value in thyroid parenchyma was 13.76 kPa, and mean muscle EI value was 15.78 kPa. The observed mean parathyroid/muscle SWE ratio was 0.5356 and the value for parathyroid/normal thyroid parenchyma was 0.5995. Using receiver operating characteristic (ROC) analysis, we found that EI below 9.74 kPa correctly identifies parathyroid tissue, with a sensitivity of 94.8%, specificity of 90.7%, and accuracy of 92.26% when compared to normal thyroid tissue. Compared with the muscle tissue, we identified that EI below 9.98 kPa has a sensitivity, specificity, and accuracy of 93.8%, 90.7%, and 91.75%, respectively. Ultrasound elastography is a helpful tool in identifying parathyroid hyperplasia in patients with chronic kidney disease. A cutoff value of 9.98 kPa can be used in 2 D-SWE for accurate diagnosis of parathyroid disease.

Vitamin D status and mortality risk among patients on dialysis: a systematic review and meta-analysis of observational studies

Background

Vitamin D deficiency is highly prevalent in patients on dialysis. Although vitamin D deficiency is closely associated with cardiovascular disease (CVD) and high mortality in the general population, the relationship between serum 25-hydroxyvitamin D [25(OH)D] and all-cause and cardiovascular mortality in dialysis patients is uncertain. We aim to explore the relationship between serum 25(OH)D levels and all-cause and cardiovascular mortality in dialysis patients.

Methods

This is a systematic review and meta-analysis of clinical studies among patients receiving maintenance dialysis. We did a systematic literature search in PubMed and Embase to identify studies reporting the relationship between serum 25(OH)D levels and all-cause and cardiovascular mortality in patients on dialysis. The search was last updated on 10 February 2017.

Results

The study included 18 moderate to high-quality cohort studies with an overall sample of 14 154 patients on dialysis. The relative risk of all-cause mortality per 10 ng/mL increase in serum 25(OH)D level was 0.78 [95% confidence interval (CI) 0.71-0.86], although there was marked heterogeneity (I2=96%, P < 0.01) that was partly explained by differences in CVD prevalence, baseline parathyroid hormone level and dialysis duration among included studies. The relative risk of cardiovascular mortality per 10 ng/mL increase in serum 25(OH)D level was 0.71 (95% CI 0.63-0.79), with substantial heterogeneity (I2=74%, P=0.004) that was largely explained by differences in study type and serum 25(OH)D measurement method.

Conclusions

In the present study, increased serum 25(OH)D level was significantly associated with lower all-cause mortality and lower cardiovascular mortality in dialysis patients.

Rapid liquid chromatography-tandem mass spectrometry method for determination of 24,25(OH)2D and 25OHD with efficient separation of 3-epi analogs

This study establishes and validates a rapid method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) without derivatization steps to simultaneously measure of 24,25(OH)₂D₂, 24,25(OH)₂D₃, 25OHD₂, and 25OHD₃, while efficiently separating the 3-epi analogs. Samples were prepared by precipitation and liquid-liquid extraction. The linearity, precision, accuracy, recovery and matrix effect of the method were thoroughly evaluated according to the Clinical & Laboratory Standards Institute guidelines. Additionally, the four vitamin D metabolites in the serum of 38 apparently healthy Chinese volunteers were evaluated. The total analysis time was 8.0 min, with efficient separation of 3-epi 24,25(OH)₂D₃ and 3-epi 25OHD₃, without interference from isomers such as 23,25(OH)₂D₃ or 1,25(OH)₂D₂, 1,25(OH)₂D₃. Good reproducibility was obtained for all four metabolites with within-run coefficient variations (CVs) of 4.07%-6.55%, 4.26%-7.84%, 2.46%-7.21%, and 4.90%-6.87% for 25OHD₃, 25OHD₂, 24,25(OH)₂D₃, and 24,25(OH)₂D₂, respectively, and the total CVs were 4.29%-6.64%, 6.14%-7.84%, 4.33%-7.21%, 5.82%-9.90%, respectively. The limit of quantification was 0.625 ng/mL for 25OHD₃ and 25OHD₂, and 0.5 ng/mL for 24,25(OH)₂D₃ and 24,25(OH)₂D₂. The relative bias of the LC-MS/MS method compared to the certified results of SRM 972a for 25OHD₃, 25OHD₂ and 24,25(OH)₂D₃ was -2.21% to 1.01%, 3.38% to 6.73%, and -7.72% to -3.9%, respectively. The mean±SD values for 25OHD, 24,25(OH)₂D and 25OHD/24,25(OH)₂D in the volunteers were 13.5±4.4 ng/mL(range:7.6-27.5 ng/mL), 0.84±0.42 ng/mL (range:0.26-2.1 ng/mL), and 18±7(range:8-37), respectively. Thus, a simple, precise LC-MS/MS method for appropriate retention and separation of vitamin D metabolites and their epi analogs was developed.

Vitamin D improves vascular function and decreases monoamine oxidase A expression in experimental diabetes

The active form of vitamin D, 1,25-dihydroxycholecalciferol (1,25(OH)₂D₃), was reported to improve vascular function in patients with diabetes, yet the underlying mechanisms remain to be fully elucidated. Monoamine oxidase (MAO), a mitochondrial enzyme, with two isoforms (A and B) that generates hydrogen peroxide (H₂O₂) as by-product, has been recently reported to contribute to the pathogenesis of endothelial dysfunction in diabetes. The present study assessed the interaction between vitamin D and MAO in the vascular wall in the setting of type 1 experimental diabetes. To this aim, diabetes was induced in male Wistar rats via a single injection of streptozotocin (STZ, 50 mg/kg, IP) and 1 month later thoracic aortas were harvested and used for organ bath studies and H₂O₂ measurements. MAO expression was assessed by immunohistochemistry and RT-PCR. Endothelial function was evaluated in isolated aortic rings in the absence vs. presence of 1,25(OH)₂D₃ (100 nM, 24 h incubation). In diabetic animals, we found a significant reduction in the endothelial-dependent relaxation to acetylcholine and an increased expression of the MAO-A isoform, respectively. Vitamin D significantly improved vascular function, mitigated oxidative stress and decreased MAO-A expression in diabetic vascular preparations. In conclusion, MAO-A is induced in diabetic aortas and vitamin D can improve diabetes-induced endothelial dysfunction by modulating the MAO-A expression.

Long-Term Survivor Characteristics in Hemodialysis Patients with Type 2 Diabetes

BACKGROUND

Data concerning long-term mortality predictors among large, purely diabetic hemodialysis collectives are scarce.

METHODS

We used data from a multicenter, prospective, randomized trial among 1,255 hemodialysis patients with type 2 diabetes mellitus (T2DM) and its observational follow-up study. The association of 10 baseline candidate variables with mortality was assessed by Cox proportional hazards regression.

RESULTS

Overall, 103 participants survived the median follow-up of 11.5 years. Significant predictors of mortality were age (hazard ratio [HR] 1.03, 95% CI 1.02-1.04), cardiovascular (HR 1.42, 95% CI 1.25-1.62) and peripheral vascular disease (HR 1.55, 95% CI 1.36-1.76), higher hemoglobin A1c (HbA1c; HR 1.08, 95% CI 1.03-1.14), and loss of self-dependency (HR 1.20, 95% CI 1.03-1.39). Higher albumin (HR 0.72, 95% CI 0.59-0.89) and body mass index (BMI; HR 0.98, 95% CI 0.96-0.99) had protective associations. There was no significant association with sex, diabetes duration, and cerebrovascular diseases. Subgroup analyses by age and diabetes duration showed stronger associations of cardiovascular disease, HbA1c, albumin, BMI, and loss of self-dependency in younger patients and/or shorter diabetes duration. Loss of self-dependency and energy resources (albumin, BMI) increased mortality more severely in women, whilst the impact of cardiovascular and peripheral vascular diseases was more pronounced in men.

CONCLUSION

Long-term mortality risk in patients with T2DM on hemodialysis was associated with higher age, vascular diseases, HbA1c, loss of self-dependency, and low energy resources. Interestingly, it does not vary between sexes. Further individualized prognosis estimation and therapy should strongly depend on age, diabetes duration, and gender.

Seasonal variations of U.S. mortality rates: Roles of solar ultraviolet-B doses, vitamin D, gene exp ression, and infections

Death rates in the U.S. show a pronounced seasonality. The broad seasonal variation shows about 25% higher death rates in winter than in summer with an additional few percent increase associated with the Christmas and New Year's holidays. A pronounced increase in death rates also starts in mid-September, shortly after the school year begins. The causes of death with large contributions to the observed seasonality include diseases of the circulatory system; the respiratory system; the digestive system; and endocrine, nutritional, and metabolic diseases. Researchers have identified several factors showing seasonal variation that could possibly explain the seasonal variations in mortality rate. These factors include seasonal variations in solar ultraviolet-B(UVB) doses and serum 25-hydroxyvitamin D [25(OH)D] concentrations, gene expression, ambient temperature and humidity, UVB effects on environmental pathogen load, environmental pollutants and allergens, and photoperiod (or length of day). The factors with the strongest support in this analysis are seasonal variations in solar UVB doses and 25(OH)D concentrations. In the U.S., population mean 25(OH)D concentrations range from 21ng/mL in March to 28ng/mL in August. Measures to ensure that all people had 25(OH)D concentrations >36ng/mL year round would probably reduce death rates significantly.

Contribution of monoamine oxidases to vascular oxidative stress in patients with end-stage renal disease requiring hemodialysis

Arteriovenous fistula (AVF) is the "lifeline" for patients with end-stage renal disease (ESRD) undergoing hemodialysis. AVF maturation failure is a poorly understood process, one of the contributors being endothelial dysfunction due to oxidative stress. Monoamine oxidases (MAOs) A and B were recently identified as novel sources of vascular oxidative stress. The aim of the present study was to assess the contribution of MAOs to the endothelial dysfunction in patients with ESDR with indication of hemodialysis. Fragments of brachial artery collaterals were harvested from ESRD patients during the surgical procedure aimed at creating the vascular access in the cubital fossa. The effect of increasing concentrations (10, 30, 100 μmol/L) of the irreversible MAO-A inhibitor, clorgyline, and MAO-B inhibitor, selegiline, on endothelial-dependent relaxation (EDR) in response to cumulative doses of acetylcholine was studied in isolated phenylephrine-preconstricted vascular rings. Hydrogen peroxide (H₂O₂) production was assessed using ferrous oxidation xylenol orange assay. We showed that incubation of brachial rings with MAO inhibitors significantly improved EDR and attenuated H₂O₂ generation in patients with ESRD. MAO-related oxidative stress might contribute to the primary dysfunction/non-maturation of the AVF and MAO inhibitors could improve maturation and long-term patency of the vascular access in dialysis patients.

Association between coping mechanisms and adherence to diabetes-related self-care activities: a cross-sectional study

In the overall management of the most chronic diseases, including diabetes mellitus (DM), adherence to recommended disease-related self-care activities is of paramount importance. The diagnosis and presence of a chronic disease may be considered a difficult and stressful situation in life, a situation in which coping mechanisms are psychological processes developed at a conscious level to manage these situations. This study aimed to explore the possible relationship between the dominance of one of the four major coping styles and adherence to diabetes-related self-care activities (DRSCAs) in the population of patients with type 2 DM (T2DM). In a cross-sectional consecutive-case population-based study design, 126 patients previously diagnosed with T2DM were enrolled. Coping mechanisms were evaluated using the Cope scale inventory, which identifies the dominant coping mechanism: problem-, emotion-, social support-, or avoidance-focused. The quality of DRSCA was evaluated using the summary of diabetes self-care activities questionnaire, in which a higher score was associated with improved adherence. In the study cohort, 45 patients (35.7%) had problem-focused coping, 37 (29.4%) had emotion-focused coping, 32 (25.4%) social support-focused coping, and 12 (9.5%) had avoidance-focused coping. Patients with emotion-focused coping had the highest level (P=0.02) of DRSCA (median 44 points), followed by patients with social support-focused coping (median 40 points) and problem-focused coping (median 36 points), while patients with avoidance-focused coping had the lowest SDSCA total score (33 points). The type of dominant coping mechanism has a significant impact on the quality of the DRSCA measures implemented by the patient to manage their diabetes. Patients with emotion-focused and social support-focused coping styles tend to have significantly increased adherence to DRSCA scores, while patients with other dominant coping styles are less interested in managing their disease.

Vitamin D levels in subjects with or without chronic kidney disease among Veterans with diabetes in North East United States

AIM

To evaluate the prevalence of vitamin D deficiency and its relation to diabetes and kidney disease in Veterans residing in the North East United States (VISN 2).

METHODS

In this retrospective study, we used data from the computerized patient record system at Stratton Veterans Administration Medical Center at Albany, NY (VHA) for those patients who had 25-hydroxyvitamin D levels and 1,25 (OH) vitamin D levels measured between 2007 and 2010. We collected demographic information including age, sex, body mass index and race; clinical data including diabetes, hypertension and CAD; and laboratory data including calcium, creatinine and parathyroid hormone (PTH) (intact). Vitamin D deficiency is defined as a serum 25-hydroxyvitamin D level of less than 20 ng/mL (50 nmol/L), and insufficiency is defined as a serum 25-hydroxyvitamin D level of 20 to 30 ng/mL (50 to 75 nmol/L).

RESULTS

Data was available for approximately 68000 subjects. We identified 64144 subjects for analysis after exclusion of duplicates. Among them, 27098 had diabetes. The mean age of subjects with diabetes was 68 ± 11 with a mean body mass index (BMI) of 32 ± 7 and duration of diabetes of 5.6 ± 3.2 years. The mean 25 (OH) vitamin D level among subjects with diabetes was 27 ± 11.6. There was no significant difference in 25 (OH) vitamin D levels between subjects with diabetes and glomerular filtration rate (e-GFR) < 60 compared to those with e-GFR ≥ 60. As expected, subjects with e-GFR < 60 had significantly lower 1,25 (OH) vitamin D levels and significantly elevated PTH-intact. Of the 64144 subjects, 580 had end-stage renal disease. Of those, 407 had diabetes and 173 did not. Vitamin D levels in both groups were in the insufficiency range and there was no significant difference irrespective of presence or absence of diabetes. Subjects with vitamin D levels less than 20 ng/mL had a higher BMI and elevated PTH, and higher HbA1C levels compared to those with vitamin D levels more than 20 ng/mL.

CONCLUSION

We conclude that we need to keep a close eye on vitamin D levels in subjects with mild chronic kidney disease as well as those with moderate control of diabetes.

Association between Serum Vitamin D Levels and Sleep Disturbance in Hemodialysis Patients

Sleep disturbance is a frequent and serious complication of hemodialysis (HD). Low serum vitamin D levels have been associated with sleep quality in non-HD subjects. Our aim was to examine the possible association between serum vitamin D levels and the presence of sleep disturbance in HD patients. We recruited 141 HD patients at the HD center of the First Affiliated Hospital of Jiaxing University during 2014–2015. Serum levels of 25-hydroxyvitamin D (25(OH)D) were determined by the competitive protein-binding assay. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Demographic, clinical and laboratory data were recorded. Meanwhile, 117 healthy control subjects were also recruited and underwent measurement of 25(OH)D. Eighty-eight patients (62.4%) had sleep disturbance (PSQI scores ≥ 5). Patients with sleep disturbance showed lower levels of 25(OH)D as compared to those without sleep disturbance (85.6 ± 37.4 vs. 39.1 ± 29.1 nmol/L, p < 0.001). In multivariate analyses, serum levels of 25(OH)D (≤48.0 nmol/L) were independently associated with sleep disturbance in HD patients (OR 9.897, 95% CI 3.356–29.187, p < 0.001) after adjustment for possible variables. Our study demonstrates that low serum levels of vitamin D are independently associated with sleep disturbance in HD patients, but the finding needs to be confirmed in future experimental and clinical studies.

Polymorphisms of Vitamin D Signaling Pathway Genes and Calcium-Sensing Receptor Gene in respect to Survival of Hemodialysis Patients: A Prospective Observational Study

We evaluated in the 7-year prospective study whether variants in vitamin D pathway genes and calcium-sensing receptor gene (CASR) are determinants of mortality in hemodialysis (HD) patients (n = 532). HRM analysis was used for GC rs2298849, GC rs1155563, RXRA rs10776909, RXRA rs10881578, and CASR rs7652589 genotyping. GC rs7041, RXRA rs749759, VDR rs2228570, and VDR rs1544410 were genotyped using PCR-RFLP analysis. The minor allele in GC rs2298849 was associated with all-cause mortality in univariate analysis (HR 1.330, 95% CI 1.046-1.692, P = 0.020). Bearers of the minor allele in GC rs2298849 demonstrated higher infection/neoplasm mortality than major allele homozygotes also in multivariate analysis (HR 2.116, 95% CI 1.096-4.087, P = 0.026). Cardiovascular mortality was associated with major homozygosity (CC) in VDR rs2228570 (HR 1.896, 95% CI 1.163-3.091, P = 0.010). CC genotype patients were more often dyslipidemic than TT genotype subjects (46.1% versus 31.9%, P = 0.047). Dyslipidemics showed higher frequency of rs1544410_rs2228570 haplotype AC than nondyslipidemics (26 versus 18%, P corr = 0.005), whereas TT genotype patients were at lower risk of dyslipidemia compared with CC/CT genotype patients (HR 0.59, 95% CI 0.37-0.96, P = 0.04). In conclusion, GC rs2298849 and VDR rs2228570 SNPs are associated with survival on HD. VDR-related cardiovascular mortality may occur due to connections of rs2228570 with dyslipidemia.