High serum 25-hydroxyvitamin D concentrations are associated with a favorable serum lipid profile

Nonlinear relationship between serum 25-hydroxyvitamin D and lipid profile in Chinese adults

Background

Previous studies on the liner associations between serum 25-hydroxyvitamin D [25(OH)D] levels and lipid profiles revealed ambiguous findings. The current study therefore tried to elucidate the possible non-linear associations between 25(OH)D and lipid profiles.

Methods

This study involved 8,516 adult participants (aged 18-74 years, males N = 3,750, females N = 4,766) recruited from the Dalian health management cohort (DHMC). The risk (OR) for specific dyslipidemias was estimated across the serum 25(OH)D levels and the cut-off value for serum 25(OH)D were determined by using logistic regression, restricted cubic spline, and piecewise linear regression methods, adjusted for age, sex, season, and ultraviolet index.

Results

In this study, a high prevalence of 25(OH)D deficiency was observed in the participants (65.05%). The level of 25(OH)D showed the inverse U-shaped correlations with the risks (ORs) of abnormal lipid profile, with inflection points observed at 23.7 ng/ml for hypercholesterolemia, 24.3 ng/ml for hypertriglyceridemia, 18.5 ng/ml for hyper-low-density lipoprotein cholesterolemia, 23.3 ng/ml for hypo-high-density lipoprotein cholesterolemia, 23.3 ng/ml for hyper-non-high-density lipoprotein cholesterol, and 24.3 ng/ml for high remnant cholesterol. The stratified analyses showed that the risk for most dyslipidemias related to deficiency of 25(OH)D was particularly increased among females aged 50-74 (except for hypertriglyceridemia, where the highest risk was among men aged 50-74 years), during winter/spring or under low/middle ultraviolet index environments.

Conclusions

Nonlinear inverse U-shaped associations were observed between 25(OH)D levels and abnormal lipid profile. The risk was particularly increased among females aged 50-74, during winter/spring period or under lower ultraviolet index environments. In vitamin D deficient subjects [25(OH)D <20 ng/ml], a positive association of serum vitamin D levels with the risk for dyslipidemia was observed, which needs a further.

Vitamin D and Dyslipidemia: Is There Really a Link? A Narrative Review

Nowadays, the interest in the extraskeletal effects of vitamin D is growing. In the literature, its several possible actions have been confirmed. Vitamin D seems to have a regulatory role in many different fields-inflammation, immunity, and the endocrine system-and many studies would demonstrate a possible correlation between vitamin D and cardiovascular disease. In this paper, we deepened the relationship between vitamin D and dyslipidemia by reviewing the available literature. The results are not entirely clear-cut: on the one hand, numerous observational studies suggest a link between higher serum vitamin D levels and a beneficial lipid profile, while on the other hand, interventional studies do not demonstrate a significant effect. Understanding the possible relationship between vitamin D and dyslipidemia may represent a turning point: another link between vitamin D and the cardiovascular system.

The Impact of Clinical Factors, Vitamin B12 and Total Cholesterol on Severity of Anorexia Nervosa: A Multicentric Cross-Sectional Study

Severe forms of Anorexia Nervosa (AN) are characterized by medical complications, psychiatric comorbidity, and high mortality. This study investigated potential associations between clinical/biological factors and the severity of AN, measured by the Body Mass Index (BMI). Red and white blood cells, hemoglobin, platelets, iron, vitamins D and B12, folate, and total cholesterol were measured in a mixed sample of 78 inpatients and outpatients. Linear regressions and one-way analyses of variance (ANOVAs) were carried out to evaluate the relationship between BMI and clinical/biochemical variables. BMI was significantly lower in hospitalized patients (F = 4.662; p = 0.034) and in those under pharmacological treatment (F = 5.733; p = 0.019) or poly-therapy (F = 5.635; p = 0.021). Higher vitamin B12 (β = -0.556, p < 0.001), total cholesterol (β = -0.320, p = 0.027), and later age at onset (with a trend towards significance) (β = -0.376, p = 0.058) were associated with a lower BMI. Increased total cholesterol and vitamin B12, later age at onset, current pharmacological treatment, and poly-therapy might be distinctive in patients with a lower BMI. In clinical practice, these findings may contribute to the early identification of AN patients at higher risk of developing complicated or chronic forms of the disorder. Further studies on larger samples are needed to identify potential predictive factors of AN severity in the framework of precision medicine.

Association between vitamin D deficiency and lipid profiles in overweight and obese adults: a systematic review and meta-analysis

OBJECTIVE

The association between vitamin D deficiency and lipid profiles in adults with overweight or obesity remains unclear and inconsistent. The aim of our study was to determine the relationship between lipid profiles and vitamin D deficiency in the overweight and obese adults.

METHODS

Four databases, including PubMed, the Web of Science, EMBASE and the Cochrane Library, were used to identify all studies on vitamin D status and lipid levels, including the serum levels of triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL), and high-density lipoprotein cholesterol (HDL). The Weighted mean difference (WMD) with 95% confidence intervals (CIs) using random-effects models was used to assess the association between the lipid profile and vitamin D deficiency.

RESULTS

Twenty-one articles that included a total of 7952 adults with overweight or obesity (BMI ≥ 25 kg/m2) were included. The overall results revealed that compared with the controls, individuals with vitamin D deficiency showed higher levels of TG (WMD = 15.01; 95%CI, 2.51-27.52) and TC (WMD = 8.61; 95%CI, 1.31-15.92). Moreover, vitamin D deficiency was related to an increased level of LDL (WMD = 6.12; 95%CI, 0.02-12.23). HDL level was inversely associated with the vitamin D deficiency status (WMD = -2.57; 95%CI, -4.26, -0.88).

CONCLUSIONS

Among the adults with overweight or obesity, the vitamin D deficient group displayed impaired lipid profiles, including increased TG, TC and LDL levels and reduced HDL level.

VITAMIN D LEVELS AND LIPID PROFILE IN PATIENTS UNDERGOING BARIATRIC SURGERY

BACKGROUND

Vitamin, mineral, and metabolic deficiencies occur in the postoperative period of bariatric surgery, in the short and long term, and are worrisome intercurrences.

AIMS

To evaluate the association of serum vitamin D levels with the lipid profile in obese patients undergoing bariatric surgery.

METHODS

Case series of patients assisted from 2010 to 2018, in a private hospital of medium and high complexity, who underwent bariatric surgery using sleeve gastrectomy or Roux-en-Y gastric bypass techniques, monitored by the same surgeon. Sociodemographic, clinical, laboratory, and anthropometric data were collected preoperatively and at 6, 12, and 24 months after surgery.

RESULTS

A total of 156 individuals, mostly female (75.6%) were monitored. The most frequent comorbidities were hepatic steatosis (76.3%) and hypertension (48.27). Regarding preoperative vitamin D levels, only 18.9% of the population had a satisfactory level (≥30 ng/mL). There was a reduction in weight and an improvement in the lipid profile after surgery. Significant correlations were observed between the lipid profile and vitamin D concentration only in the sample submitted to the Roux-en-Y gastric bypass technique: negative correlation between total cholesterol and vitamin D two years after surgery; positive correlation between triglycerides and vitamin D one year after surgery; and negative correlation between high-density lipoprotein and vitamin D two years post-surgery.

CONCLUSIONS

It is essential to routinely monitor vitamin D levels and lipid profile pre- and postoperatively in order to avoid damage associated with this vitamin deficiency.

Evaluating the effect of atorvastatin exposure and vitamin D levels on lipid outcomes in people with HIV-1 with suppressed HIV-1 RNA and LDL cholesterol <130 mg/dL

INTRODUCTION

Cardiovascular disease (CVD) has become a leading cause of morbidity and mortality among people with HIV. Atorvastatin is known to reduce cardiovascular risk. We (1) compared atorvastatin concentrations between different boosted protease inhibitors (PIs) and with lipid outcomes and (2) compared pre-atorvastatin 25-OH vitamin D levels with atorvastatin concentrations and with lipid outcomes, in people with HIV with suppressed HIV-1 RNA and low-density lipoprotein cholesterol (LDL-C) <130 mg/dL.

METHODS

A5275 was a randomized, double-blind, placebo-controlled crossover study of atorvastatin in virally suppressed people with HIV with fasting LDL-C <130 mg/dL. We analyzed results over the 20 weeks of active atorvastatin treatment. Atorvastatin was initiated at 10 mg daily and increased to 20 mg daily after 4 weeks if there were no findings of toxicity. Atorvastatin trough concentrations were measured at week 20. Participants took combination antiretroviral therapy (ART) that included a boosted PI throughout.

RESULTS

Overall (n = 67), 70% of participants were male, and the median age was 51 years. There was no apparent association between atorvastatin trough concentrations and pre-atorvastatin vitamin D levels (r = 0.01, p = 0.9) or by boosted PI (p = 0.20). Median pre- to post-atorvastatin change was -39.0 mg/dL in fasting total cholesterol, -40.4 ng/mL in lipoprotein-associated phospholipase A2 (LP-PLA2), and -13.8 U/L in oxidized LDL, with all changes negatively correlated with atorvastatin trough concentrations (r = -0.19, -0.09, -0.21; p ≥ 0.096).

CONCLUSIONS

No apparent associations between pre-atorvastatin vitamin D levels and outcomes were observed (all p > 0.70). In virologically suppressed people with HIV, higher atorvastatin concentrations were marginally associated with greater decreases in lipid outcomes.

Association between Vitamin D Status and Health Status of Adults in Western Libya

Vitamin D (VitD) is essential for health and preventing diseases. This study aimed to investigate the possible association between VitD status and health status in 306 Libyan male and female young adults (18–25 Y) and adults (26–65 Y). There were 89.54% of subjects that had VitD levels below normal (<30 ng/mL), of which 45.42% were VitD deficient (<10 ng/mL) and 44.12% were VitD insufficient (10–29.9 ng/mL). VitD deficiency was associated with higher fasting blood sugar (FBS), low-density lipoprotein (LDL), and triacylglycerol (TAG) levels. Young adults had lower VitD levels than adults, which was associated with some health conditions. VitD insufficiency was associated with higher body mass index (BMI) values in adults, especially females, with higher FBS levels in adult males and higher hemoglobin A1c (HbA1c) levels in adult females. VitD deficiency in young adults was associated with higher TAG levels (more likely in adults) and lower high-density lipoprotein (HDL) values. Furthermore, VitD deficient adult females appeared to have a higher risk of sleeping problems, psychological disorders, headache, and osteoporosis, whereas their male counterparts appeared to be at a higher risk of developing obesity and diabetes mellitus (DM). Findings showed a serious prevalence of VitD inadequacy in the Libyan population, which appears to negatively affect health status and be associated with some disease conditions.

Higher Dietary Vitamin D Intake Influences the Lipid Profile and hs-CRP Concentrations: Cross-Sectional Assessment Based on The National Health and Nutrition Examination Survey

Background. An unanswered question in the field of nutrition is whether there is an association between vitamin D intake and the lipid profile in adults. We conducted this cross-sectional study in order to investigate the impact of vitamin D intake on the lipid profile of adults in the context of the 2017-2018 National Health and Nutrition Examination Survey (NHANES). Methods. Serum lipids and high-sensitivity C-reactive protein (hs-CRP) concentrations and the Vitamin D intake in 2588 people aged 19 to 70 years was collected using laboratory analysis and 24-h recall, respectively. The one-way ANOVA test was used to compare quantitative variables and the chi-squared test was used to compare qualitative ones. Multivariate logistic regression for three models was performed to assess the odds ratio (OR) of high total cholesterol (TC) (>200 mg/dL), triglycerides (TG) (>150 mg/dL), low-density lipoprotein cholesterol (LDL-C) (>115 mg/dL), high-density lipoprotein cholesterol (HDL-C) (<40 mg/dL) and hs-CRP (>1 mg/l) based on the tertiles of dietary vitamin D (D2 + D3) intake. Results. After adjusting for age, sex, race, body mass index, serum 25-hydroxyvitamin D2, alcohol intake, energy intake, protein intake, carbohydrate intake, fiber intake and fat intake, individuals in the tertile with the highest versus lowest vitamin D intake (>1 mcg/day vs. <0.10 mcg/day) had lower odds of displaying elevated TC, LDL-C and hs-CRP concentrations (OR 0.57; CI: 0.37 to 0.88; P-trend: 0.045, OR 0.59; CI: 0.34 to 1.01; P-trend: 0.025 and OR 0.67; CI: 0.45 to 0.99; P-trend: 0.048, respectively). Based on the results of the logistic regression, no correlation between vitamin D intake and changes in TG or HDL-C values was noted. Conclusions. Our cross-sectional study indicates that higher dietary vitamin D (D2 + D3) intake is associated with lower TC, LDL-C and hs-CRP levels. No relationship between dietary vitamin D intake and TG or HDL-C values was detected. Further large-scale randomized trials are needed to evaluate the actual association between dietary vitamin D intake and the lipid profile.

The Level of Selected Blood Parameters in Young Soccer Players in Relation to the Concentration of 25(OH)D at the Beginning and End of Autumn

This study aimed to demonstrate the changes of selected blood parameters in relation to 25(OH)D concentration during the autumn period in young soccer players. A total of 35 participants’ results (age: 17.5 ± 0.6 years, body mass 71.3 ± 6.9 kg) were tested twice: in mid-September and in mid-December and divided into subgroups with regard to two criteria. First, according to the initial level of the 25(OH)D concentration (optimal group—ODG, suboptimal group—SDG), second, according to drops in 25(OH)D concentration (high drop group—HDG, low drop group—LDG). A significant decrease (p < 0.001) in the 25(OH)D concentration was reported in the total group (TGr) and in all subgroups. Blood parameters such as white blood cells, red blood cells, haemoglobin and haematocrit increased significantly (p < 0.05) in TGr during the analysed period of time. The analysis of changes in the lipid profile did not expose significant differences except triglycerides. The asparagine amino transferase and creatine kinase activity decreased significantly after autumn in all analysed groups. The declining level of 25(OH)D concentration should be compensated (e.g., with vitamin D supplementation) during autumn. Applied training loads could also influence the blood parameters variability in young soccer players. Regular measurements of 25(OH)D concentration are helpful in identifying potential drops and allows for the preparation of individual supplementation plans for the players.

Beneficial effects of vitamin D in the management of untreated hyperlipidemia in diabetic patients in Erbil, Iraq

Hyperlipidemia is highly prevalent among type 2 diabetes mellitus (T2DM) patients. As hyperlipidemia plays a major part in atherosclerosis development and progression, this occurrence is linked to a significantly raised risk of cardiovascular disease. This study aims to assess the effects of vitamin D supplementation on lipid parameters in T2DM patients with untreated hyperlipidemia. Thirty-five T2DM patients with hyperlipidemia and vitamin D deficiency were supplemented with vitamin D for three months. Serum 25-hydroxyvitamin D (25[OH]D), calcium, lipid parameters, atherogenic indices, glucose, and HbA1c were recorded before and after the intervention. After supplementation, there was a statistically significant reduction in VLDL-C and triglycerides. Triglycerides showed a significant negative correlation with 25(OH)D. Atherogenic indices and HDL-C also improved significantly. Vitamin D supplementation had beneficial effects on the lipid profile of T2DM patients with untreated hyperlipidemia and vitamin D deficiency. Thus, vitamin D could be a valuable adjuvant therapy for these patients.

Relationship between vitamin D and cholesterol levels in STEMI patients undergoing primary percutaneous coronary intervention

BACKGROUND AND AIMS

Special interest has been raised on vitamin D association with the metabolic profile, potentially interfering with lipid parameters and lipid-lowering therapies. The aim of the present study was to assess the impact of vitamin D on the cholesterol levels among patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI.

METHODS AND RESULTS

A consecutive cohort of 450 patients admitted for STEMI treated with pPCI were retrospectively identified and divided according to tertiles values of 25(OH). The levels of 25(OH)D were assessed at admission by chemiluminescence immunoassay kit LIAISON®Vitamin D assay (Diasorin Inc). Lower vitamin D was associated to a higher use of diuretics (p = 0.03), lower prevalence of lesions on bifurcations (p = 0.001) and smaller diameter of the target coronary vessel (p = 0.03), but higher coronary calcifications (p = 0.007). Total and LDL cholesterol levels were significantly increased in patients with lower vitamin D (p = 0.05 and p = 0.005), inversely relating with total cholesterol (r = -0.09, p = 0.06) and LDL-C (r = -013, p = 0.007), and directly with HDL-C (r = 0.16, p = 0.001). Results were not affected by statin therapy, with a significant relationship being confirmed for atherogenic lipids, but not for HDL-C in statin treated patients. In fact, at multivariate analysis, vitamin D in lower tertiles emerged as an independent predictor of LDL-C elevated or above the target (adjusted OR [95%CI] = 2.6 [1.51-4.44], p = 0.001).

CONCLUSION

The present study shows that among patients with STEMI undergoing primary revascularization, lower levels of vitamin D are independently associated with a more atherogenic lipid profile. Similar results were observed in statin treated or naïve patients.

Vitamin D Related Gene Polymorphisms and Cholesterol Levels in a Mediterranean Population

In addition to its role in bone health, vitamin D (VitD) has been implicated in several pathological conditions. Specifically, VitD deficiency has been linked to an increased risk of dyslipidemia. Atherogenic dyslipidemia is characterized by increased low-density lipoprotein-cholesterol (LDL-C) and decreased high-density lipoprotein-cholesterol (HDL-C). In this study, we examined the association of six single nucleotide polymorphisms (SNPs) in VitD-related genes with VitD and lipid levels, in a cohort of 460 Lebanese participants free from chronic diseases. Our results showed no association of the examined SNPs with VitD concentrations. However, the presence of the minor allele in rs10741657G>A of CYP2R1 was associated with increased levels in LDL-C (β = 4.95, p = 0.04)] and decreased levels in HDL-C (β = −1.76, p = 0.007)]. Interestingly, rs10741657G>A interacted with gender to increase LDL-C levels in females (β = 6.73 and p = 0.03) and decrease HDL-C levels in males HDL-C (β = −1.09, p = 0.009). In conclusion, our results suggest that rs10741657 G>A in CYP2R1 is associated with circulating LDL-C and HDL-C levels in a Lebanese cohort. Although this association was gender-specific, where rs10741657G>A was associated with increased LDL in females and decreased HDL in males, the presence of the minor allele A was associated with increased cardiovascular risk in both genders. These findings need to be validated in a larger population. Further investigations are warranted to elucidate the molecular mechanism of VitD polymorphism and dyslipidemia.

Sex and Age Differences Modulate Association of Vitamin D with Serum Triglyceride Levels

The sex and age differences in the relationship between vitamin D and lipid levels remain unclear. This retrospective study investigated the correlations between serum 25-hydroxyvitamin D levels and various biomarkers, along with the sex and age differences in these associations, among 573 men and 436 women during physical check-ups. The mean age of the study population was 51.4 years, and 66% of people had serum 25(OH)D levels below 30 ng/mL. People aged over 65 years had higher 25(OH)D levels than those younger than 65 years, and women had lower 25(OH)D levels than men. Younger age (odds ratio (OR) per year = 1.044, 95% CI, 1.029−1.059, p < 0.0001), female sex (OR = 1.779, 95% CI, 1.149−2.755, p = 0.0097), and elevated serum triglyceride (TG) levels (OR per 1 mg/dL = 1.005, 95% CI, 1.002−1.007, p = 0.0002) were all independent risk factors for vitamin D deficiency. Serum 25(OH)D levels were inversely associated with TG levels. The positive association between vitamin D deficiency and hypertriglyceridemia was significant in men (not in women) and in those aged between 50 and 65 years. In conclusion, younger individuals, women, and middle-aged men with hypertriglyceridemia are at higher risk of vitamin D deficiency.

The Relationship of 25(OH)D3 with Diabetes Mellitus and the Mediation Effect of Lipid Profile in Chinese Rural Population of Henan Province

Background and Objectives: Studies suggest that vitamin D is involved in the development of type 2 diabetes mellitus (T2DM) and influences serum lipids levels, while lipid disorders are also closely related to T2DM. This study attempts to explore the complex relationship of serum 25(OH)D₃, serum lipids, and T2DM among Chinese population. Materials and Methods: A cross-sectional study was carried out among 2326 subjects. The chi-square (χ²) test was applied to compare the prevalence of T2DM or dyslipidemia between two serum 25(OH)D₃ levels. Linear regression was applied to analyze the correlation between serum lipids and 25(OH)D₃ contents. Univariate and logistic analysis were used to explore the relationship between two lipid levels and T2DM. Mediation analysis was used to explore whether serum lipids mediate the relationship between two serum 25(OH)D₃ levels and T2DM. Results: Compared to subjects with 25(OH)D₃ ≥ 30 ng/mL, subjects with 25(OH)D₃ < 30 ng/mL were higher in the prevalence of T2DM. The occurrences of high TG and low HDL-C were significantly higher in vitamin D deficiency and insufficiency than those in vitamin D sufficiency. Serum 25(OH)D₃ content showed a reverse correlation with TC, TG, and LDL-C, but positive correlation with HDL-C. The odds ratios (ORs) (95% confidence intervals, 95%CI) of T2DM by comparing TG ≥ 2.26 mmol/L vs. TG < 2.26 mmol/L and HDL-C < 1.04 mmol/L vs. HDL-C ≥ 1.04 mmol/L in all participants were 2.48 (1.94–3.18) and 1.37 (1.07–1.75), respectively. Serum TG or HDL-C level partially mediated the relationship between two 25(OH)D₃ level and T2DM. Conclusions: Serum 25(OH)D₃ < 30 ng/mL seems to be associated with T2DM or dyslipidemia (high TG and low HDL-C) in our study, but there is still no proof of a cause–effect relationship. Moreover, serum TG or HDL-C level partially mediated the relationship between 25(OH)D₃ levels and T2DM.

Vitamin D status is favorably associated with the cardiovascular risk factors in adults with obesity

BACKGROUND & AIMS

Previous investigations have been indicated that vitamin D deficiency is an amendable risk for cardiovascular disease (CVD) in the general populations. Limited data is available concerning the relationship of vitamin D status and risk factors of CVD in the individuals with obesity and the existing data are highly controversial. We investigated whether serum vitamin D situation is related to multiple traditional CVD risk factors in Iranian obese subjects.

METHODS

A cross-sectional study was done among 214 Iranian adults with obesity (94 males and 120 females) aged 20-60 years, who attended the specialized outpatient clinics in Zabol city. Participants were categorized as vitamin D sufficient, insufficient, and deficient according to their serum 25(OH)D concentrations. Afterward, the presence of hypercholesterolemia, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C) as well as diabetes, hypertension, and high serum concentrations of high-sensitivity C-reactive protein (hs-CRP) as CVD risk factors were evaluated in the participants.

RESULTS

There was a noticeable regular trend regarding hypercholesterolemia (p = 0.008), high LDL-C (p = 0.024), hypertension (p = 0.021), and high hs-CRP (p < 0.0001) across various categories of vitamin D status. In adjusted model, vitamin D-deficient subjects were at higher risk for having hypercholesterolemia (OR: 3.22, p = 0.031), high LDL-C (OR: 2.37, p = 0.047), hypertension (OR: 2.32, p = 0.042), and high hs-CRP (OR: 5.49, p = 0.001) than ones with sufficient vitamin D status.

CONCLUSIONS

Vitamin D deficiency in obese subjects was found to be strongly related to higher risk of unfavorable lipid profile, hypertension, and high hs-CRP.

Association between deficient and insufficient 25(OH)D serum concentrations and cardiometabolic risk factors: Findings of a population-based study with older adults of southern Brazil

To investigate the association between deficient and insufficient serum concentrations of 25(OH)D and cardiometabolic risk factors (CMRF), considering that both conditions are important predictors of cardiovascular disease and diabetes mellitus. A cross-sectional study with a subsample of 526 older adults (63-93 years old) who participated in the second wave of the population-based longitudinal study EpiFloripa Idoso. The CMRF analyzed were abdominal obesity, high fasting glucose, high blood pressure, high triglycerides and high LDL-cholesterol. The exposure variable was 25(OH)D serum concentration (≤20 ng/mL = deficient; 21-29 ng/mL = insufficient, ≥30-<100 ng/mL = sufficient). The prevalences of 25(OH)D deficiency and insufficiency were estimated at 21.9% and 43.7%, respectively. The adjusted OR of prevalence of the abdominal obesity (OR 1.99;1.12-3.54), high blood pressure (OR 2.58;1.35-4.94) and high LDL-cholesterol (OR 2.73;1.63-4.6) were higher among those with deficient serum concentration of 25(OH)D. Participants with insufficient serum concentrations of 25(OH)D also presented higher adjusted OR of prevalence for abdominal obesity (OR 2.14;1.31-3.48). No significant adjusted association was found between 25(OH)D with the outcomes high fasting glucose and high triglycerides. Significant effect modification/interaction by age was also observed in the tested associations for abdominal obesity (P < 0.001), blood pressure (P < 0.001) and LDL-cholesterol (P < 0.001), in which deficient and insufficient 25(OH)D values were associated with higher values of these FRCM. 25(OH)D serum concentrations between 30 and 100 ng/mL can contribute to preventing and controlling CMRF such as abdominal obesity, high blood pressure and high LDL-cholesterol. The understanding this particular interaction may indicate ways to prevent/control cardiometabolic outcomes, health problems common in the older adults.

Association of changes in lipid levels with changes in vitamin D levels in a real-world setting

In clinical trials, vitamin D supplementation has been reported to reduce serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) but not high-density lipoprotein cholesterol (HDL-C). In this cohort study we evaluated the association between changes in vitamin D (25-hydroxyvitamin D) and changes in lipid levels in a real-world setting. Changes in lipid levels over a 1-year period were evaluated among individuals whose vitamin D levels increased (group 1) or decreased (group 2) by ≥ 10 ng/mL in year 2018 versus 2017 (cohort 1; n = 5580), in 2019 versus 2018 (cohort 2, n = 6057), or in 2020 versus 2019 (cohort 3, n = 7249). In each cohort, levels of TC, LDL-C, and TG decreased in group 1 and increased in group 2. Between-group differences in average changes in the 3 cohorts ranged from 10.71 to 12.02 mg/dL for TC, from 7.42 to 8.95 mg/dL for LDL-C, and from 21.59 to 28.09 mg/dL for TG. These differences were significant after adjusting for age, sex, race, education, body mass index, blood pressure, smoking status, geographical location, and baseline levels of vitamin D and lipids (P < 0.001). Changes in vitamin D levels were not significantly associated with changes in HDL-C levels.

Circulating serum vitamin D levels in relation to metabolic syndrome in children: A systematic review and dose-response meta-analysis of epidemiologic studies

Findings from epidemiologic studies that evaluated the relationship between serum vitamin D levels and metabolic syndrome (MetS) in children were contradictory. We conducted a systematic review and meta-analysis on the relation of serum 25(OH)D levels and MetS in children. A comprehensive search was conducted in electronic databases, up to November 2020. Eleven cross-sectional studies that reported the link between circulating vitamin D levels and MetS in children were included in the analysis. Combining 11 effect sizes from 11 cross-sectional studies with 22,196 participants revealed that highest versus lowest serum vitamin D concentration was significantly associated with a 50% reduced odds of MetS in children (OR: 0.50; 95%CI: 0.39, 0.64). Subgroup analysis by study location revealed decreased odds of MetS in both non-Asian (OR: 0.45; 95%CI: 0.33, 0.63) and Asian countries (OR: 0.54; 95%CI: 0.39, 0.76) with no heterogeneity in these subgroups. When we confined the studies to those with representative populations (n = 21,611), a significant inverse association was found between highest versus lowest circulating vitamin D level and MetS (OR: 0.55; 95%CI: 0.42, 0.71). Dose-response analysis showed that each 10 ng/ml (or 25 nmol/L) in serum vitamin D was linearly related to a 12% reduced odds of MetS (OR: 0.88; 95%CI: 0.78, 0.99) in children. A nonlinear association was also detected between serum 25(OH)D and MetS. This meta-analysis revealed that circulating vitamin D concentration was inversely associated with odds of MetS in children, in a dose-response fashion. The same finding was found in the studies with representative populations.

Effects of vitamin D supplementation on apolipoprotein A1 and B100 levels in adults: Systematic review and meta-analysis of controlled clinical trials

Cardiovascular disease (CVD) is a leading cause of death around the world. According to the studies, apolipoproteins A1 and B100 play crucial role in CVD development and progression. Also, findings have indicated the positive role of vitamin D on these factors. Thus, we conducted the present meta-analysis of randomized controlled trials (RCTs) to demonstrate the impact of vitamin D supplementation on apolipoproteins A1 and B100 levels in adults. PubMed and Scopus databases and Google Scholar were searched up to 21 December 2020. Relevant articles were screened, extracted, and assessed for quality based on the Cochrane collaboration's risk of bias tool. Data analysis conducted by random-effect model and expressed by standardized mean difference (SMD). The heterogeneity between studies was assessed by I-squared (I2) test. Subgroups and sensitivity Analyses were also conducted. Seven RCTs were identified investigating the impact of vitamin D on Apo A1 levels and six on Apo B100 levels. The findings showed the insignificant effect of vitamin D supplementation on Apo A1 (SMD=0.26 mg/dL; 95% confidence interval (CI), -0.10, 0.61; P = 0.155) and Apo B100 (standardized mean difference (SMD)=-0.06 mg/dL; 95% CI, -0.24, 0.12; P = 0.530) in adults. There was a significant between-study heterogeneity in Apo A1 (I2=89.3%, P < 0.001) and Apo B100 (I2 = 57.1%, P = 0.030). However, significant increase in Apo A1 in daily dosage of vitamin D (SMD=0.56 mg/dL; 95% CI, 0.02, 1.11; P = 0.044) and ≤12 weeks of supplementation duration (SMD=0.71 mg/dL; 95% CI, 0.08, 1.34; P = 0.028) was observed. No significant effects of vitamin D on Apo A1 and Apo B100 levels after subgroup analysis by mean age, gender, study population, dosage and duration of study. Overall, daily vitamin D supplementation and ≤12 weeks of supplementation might have beneficial effects in increasing Apo A1 levels, however, future high-quality trials considering these a primary outcome are required.

Independent and Combined Effects of Calcium and Vitamin D Supplementation on Blood Lipids in Overweight or Obese Premenopausal Women: A Triple-Blind Randomized Controlled Clinical Trial

Background:

Dyslipidemia is often associated with obesity and contributes to the increased risk of atherosclerosis, heart disease, and stroke. This study was designed to evaluate the independent or combined effect of calcium and vitamin D (Ca + Vit D) supplementation on blood lipid profile in overweight or obese premenopausal women.

Methods:

This study is a triple-blind, randomized, parallel, placebo-controlled trial. About 100 overweight or obese (body mass index (BMI) of 25–40 kg/m²) premenopausal (aged 30–50 years) women, recruited from Shiraz University of Medical Sciences (SUMS) clinics, were allocated into 4 groups: (1) calcium (Ca) supplementation (2 tablets per day; each containing 500 mg calcium carbonate), (2) vitamin D (Vit D) supplementation (2 tablets per day; each containing 200 IU vitamin D3), (3) Ca + Vit D supplementation (2 tablets per day; each containing 500 mg calcium carbonate plus 200 IU vitamin D3), (4) placebo supplementation (2 tablets per day, containing micro-cellulose). All participants received a 500 kcal energy-restricted diet. Blood lipids, serum vitamin D, and anthropometric indices were measured at baseline and after 8 weeks. Physical activity and 3-day dietary records were taken at baseline and every 4 weeks during the intervention.

Results:

At 8 weeks, triglyceride levels were significantly decreased in the Ca group (P = 0.002). Low-density lipoprotein (LDL) levels were decreased in the Ca + Vit D group (P = 0.04) and high-density lipoprotein (HDL) levels decreased in both the Ca and Ca + Vit D groups (P = 0.006, P = 0.004, respectively). The results of one-way ANOVA indicated that changes in the serum lipid profile levels were not significantly different among the four groups (P = 0.90, P = 0.86, P = 0.61, P = 0.27, and P = 0.19, respectively for TG, TC, LDL, HDL, and LDL/HDL). The results were not significant even after adjusting for potential covariates.

Conclusions:

Although the results were not significantly different among the four treated groups at 8 weeks, within-group changes like the reduction in triglyceride and LDL levels, respectively in the Ca group and Ca + Vit D group, and HDL levels in both the Ca and Ca + Vit D groups were significant. These changes may have potentially significant public health implications.

The Interdependency and Co-Regulation of the Vitamin D and Cholesterol Metabolism

Vitamin D and cholesterol metabolism overlap significantly in the pathways that contribute to their biosynthesis. However, our understanding of their independent and co-regulation is limited. Cardiovascular disease is the leading cause of death globally and atherosclerosis, the pathology associated with elevated cholesterol, is the leading cause of cardiovascular disease. It is therefore important to understand vitamin D metabolism as a contributory factor. From the literature, we compile evidence of how these systems interact, relating the understanding of the molecular mechanisms involved to the results from observational studies. We also present the first systems biology pathway map of the joint cholesterol and vitamin D metabolisms made available using the Systems Biology Graphical Notation (SBGN) Markup Language (SBGNML). It is shown that the relationship between vitamin D supplementation, total cholesterol, and LDL-C status, and between latitude, vitamin D, and cholesterol status are consistent with our knowledge of molecular mechanisms. We also highlight the results that cannot be explained with our current knowledge of molecular mechanisms: (i) vitamin D supplementation mitigates the side-effects of statin therapy; (ii) statin therapy does not impact upon vitamin D status; and critically (iii) vitamin D supplementation does not improve cardiovascular outcomes, despite improving cardiovascular risk factors. For (iii), we present a hypothesis, based on observations in the literature, that describes how vitamin D regulates the balance between cellular and plasma cholesterol. Answering these questions will create significant opportunities for advancement in our understanding of cardiovascular health.

Metabolic Signatures of Genetically Elevated Vitamin D Among Chinese: Observational and Mendelian Randomization Study

CONTEXT

Observational studies have suggested that higher circulating 25-hydroxyvitamin D [25(OH)D] levels are associated with favorable serum lipids and related metabolites. However, whether such observations reflect causality remains unclear.

OBJECTIVE

We aimed to investigate the causal effect of elevated 25(OH)D with a detailed systemic metabolite profile in Chinese adults.

METHODS

A total of 225 lipid and other metabolites were quantified in 4662 individuals in the China Kadoorie Biobank. Instrumental variable analyses were performed to test the causal associations of plasma 25(OH)D with lipids and metabolites.

RESULTS

Higher plasma 25(OH)D was related to favorable lipid profiles in observational analyses. The genetic risk score was robustly correlated with observed 25(OH)D (beta[SE] = 3.54 [0.32]; P < 1 × 10-5, F-statistic = 122.3) and explained 8.4% of the variation in 25(OH)D in the Chinese population. For all individual metabolites, the causal estimates were not significant at the threshold P < 5 × 10-4 (multiple testing corrected). However, a Mendelian randomization (MR) estimate showed that per 1-SD increase in genetically determined 25(OH)D was suggestive of association with decreased levels of cholesterol, lipoprotein particles, and phospholipids within very small very low-density lipoprotein (VLDL) and intermediate-density lipoprotein (IDL) (P ≤ 0.05, nominal significance). For amino acids, fatty acids, ketone bodies, glycoprotein acetyls, fatty acids, and other traits, we did not observe any significant causal association.

CONCLUSIONS

The MR analysis of metabolic data based a population-based cohort suggested a potential causal association of plasma 25(OH)D with cholesterol, lipoprotein particle, phospholipid concentrations, and total lipids within very small VLDL and IDL. Our findings highlight a long-term effect of 25(OH)D levels in maintaining healthy lipid metabolism.

Vitamin D equilibrium affects sex-specific changes in lipid concentrations during Christian Orthodox fasting

We aimed to evaluate sex differences in changes of lipid profiles in a cohort of metabolically healthy adults following Orthodox fasting (OF), as well as to assess a potential role of vitamin D status in mediating these variations. 45 individuals (24 premenopausal females, 53.3 %) with mean age 48.3 ± 9.1 years and mean Body Mass Index 28.7 ± 5.8 kg/m² were prospectively followed for 12 weeks. Anthropometry, dietary and biochemical data regarding serum lipids, and vitamin D status were collected at baseline, 7 weeks after the implementation of OF, and 5 weeks after fasters returned to their standard dietary habits (12 weeks from baseline). According to 25-hydroxy-vitamin D [25(OH)D] measurements, participants were divided into two groups: those with concentrations above and below the median of values. Females with 25(OH)D concentrations below the median manifested a non-significant reduction by approximately 15 % in total and low-density lipoprotein cholesterol during the fasting period, followed by a significant increase 5 weeks after OF cessation (170.7 vs. 197.5 and 99.6 vs. 121.0 mg/dl respectively, p < 0.001). In contrast, males with 25(OH)D levels below the median demonstrated an inverse, non-significant trend of increase in lipid concentrations during the whole study period. Our findings suggest strikingly different inter-gender lipid responses to a dietary model of low-fat, mediated by vitamin D status. Further studies are necessary to reveal the underlying mechanisms and assess the importance of these differences with respect to cardiovascular health and the benefit of vitamin D supplementation strategies.

Sex-Specific Association between Serum Vitamin D Status and Lipid Profiles: A Cross-Sectional Study of a Middle-Aged and Elderly Chinese Population

Studies have shown that vitamin D status might be associated with dyslipidaemia, but results are conflicting and there might exist sex differences. The aim of our study was to explore the sex-specific association between vitamin D status and serum lipids and atherogenic index of plasma (AIP, a predictor for atherosclerosis) among Chinese middle-aged and elderly adults. A total of 4,021 middle-aged and elderly participants from a health management centre were included in this cross-sectional study. The individuals were classified into tertiles according to serum 25(OH)D. Linear and logistic regression models were used to estimate the association between vitamin D levels and serum lipids among the tertiles. The mean serum 25(OH)D level was 21.60 (16.60-27.20) ng/mL in all participants. After adjusting for potential confounders, a 10 ng/mL increase in 25(OH)D was associated with decreases of 1.156 mmol/L in triglycerides (TGs) and 0.068 in the AIP and an increase of 0.051 mmol/L in high-density lipoprotein cholesterol (HDL-C) in all subjects. In addition, 25(OH)D deficiency was associated with an increased prevalence of hypertriglyceridaemia (odds ratio (OR), 1.880; 95% confidence interval (CI), 1.351-2.615), hypoalphalipoproteinaemia/HDL (OR, 1.505; 95% CI, 1.146-1.977) and abnormal AIP (OR, 1.933; 95% CI, 1.474-2.534) in males, and 25(OH)D-deficient women had a 2.02-fold higher risk for hypoalphalipoproteinaemia/HDL than women with sufficient 25(OH)D levels (95% CI, 1.044-3.904; all p values <0.05). Vitamin D deficiency was positively associated with the prevalence of dyslipidaemia and abnormal AIP in the middle-aged and elderly Chinese population. And this association was stronger in men than in women.

Vitamin D Deficiency in Lebanese Adults: Prevalence and Predictors from a Cross-Sectional Community-Based Study

METHODS

A random sample of Lebanese adults residing in the Greater Beirut area was selected based on area probability and multistage cluster sampling. Data from 446 participants (68% females) with mean age 45.3 ± 15 years were used for the analyses. Participants were recruited between March and May. Serum 25-hydroxyvitamin D levels were measured using electrochemiluminescent immunoassay.

RESULTS

Vitamin D deficiency was highly prevalent whether using the cutoff of 50 nmol/L or using the more conservative cutoff of 30 nmol/L; more specifically, 71.9% and 39.1% of the study population were deficient using the above cutoffs, respectively In the bivariate analyses, gender, BMI and body fat mass, socioeconomic factors (income and education level), alcohol consumption, dietary intake of fat and of vitamin D, serum LDL-cholesterol, and serum creatinine were all associated with vitamin D status. After adjustment for multiple covariates, age, income, alcohol consumption, and serum creatinine were independent predictors of vitamin D deficiency.

CONCLUSION

Vitamin D deficiency is highly prevalent in Lebanon. Preventive measures should target the modifiable risk factors.

Association of vitamin D status with liver and kidney disease: A systematic review of clinical trials, and cross-sectional and cohort studies

Abstract. Background: Vitamin D deficiency (VDD) is a major public health problem. There are few comprehensive systematic reviews about the relationship between Vitamin D status and liver and renal disease in Iran.

Methods: We systemically searched the following databases: Web of Science; PubMed; Cochrane Library; Scopus; Science Direct; Google Scholar and two Iranian databases (Scientific Information Database (SID) and IranMedex) up until November 2017 to identify all randomized control trials (RCTs), case control, cross-sectional and cohort studies investigating the association between vitamin D and any form of liver or kidney disease.

Results: Vitamin D insufficiency, or deficiency (VDD), is highly prevalent in Iran, reports varying between 44.4% in Isfahan to 98% in Gorgan. There is also a high prevalence of VDD among patients with liver or kidney disease, and the administration of vitamin D supplements may have beneficial effects on lipid profile, blood glucose, liver function and fatty liver disease, and bone health. Low serum vitamin D levels are related with abnormalities in these laboratory and clinical parameters.

Conclusion: VDD is prevalent in patients with chronic liver or renal disease in Iran. There appear to be several beneficial effects of vitamin D supplementation in vitamin D deficient patients with liver or kidney disease.

Vitamin D and Lipid Profiles in Postmenopausal Women: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

Background and Aim: It is known that hyperlipidemia and low vitamin D level are risk factors associated with cardiovascular disease (CVD). However, the effect of vitamin D administration on lipid profiles in postmenopausal women remains unclear. This study aims to evaluate the effect of vitamin D on lipid profiles in postmenopausal women based on meta-analysis and systemic review. Methods: The literature search was performed in multiple databases (Scopus, PubMed/Medline, Web of Science, and Embase) from 1997 to 2021. The statistical analysis was performed using the Stata software version 14 (Stata Corp. College Station, Texas, United States). The effects of vitamin D administration of the lipid profiles, including Triacylglycerol (TG), LDL-Cholesterol (LDL-C), HDL-Cholesterol (HDL-C), and Total Cholesterol (TC) were evaluated by the Der Simonian and Laird random effects model. The weighted mean difference (WMD) and 95% confidence intervals (CI) were calculated. Results: The level of TG changed significantly by -3.76 mg/dl (CI: -6.12 to -1.39, p = 0.004) and HDL-C by 0.48 mg/dl (CI: -0.80 to -0.15, p = 0.004) in vitamin D administration group [11 eligible trials (placebo = 505 participants, vitamin D intervention = 604 participants)] compared to the control group in the postmenopausal women. Taking into account this comparison between groups, in contrast, the level of LDL-Cholesterol (LDL-C) (WMD: 0.73 mg/dl, 95% CI: -1.88, 3.36, p = 0.583) and TC (WMD: 0.689 mg/dl, CI: -3.059 to 4.438, p = 0.719) did not change significantly. Conclusion: In conclusion, the vitamin D administration in postmenopausal women, decreased the concentrations of TG, and HDL-C, but have no effects on LDL-C and TC.

Vitamin D Deficiency as a Predictor of a High Prevalence of Coronary Artery Disease in Pancreas Transplant Candidates With Type 1 Diabetes

INTRODUCTION

Pancreas transplantation is a high-risk procedure in terms of cardiovascular complications. Therefore, identification of all cardiovascular risk factors is crucial to prevent cardiovascular complications after pancreas transplantation. Vitamin D deficiency (VDD) appears to be a potential risk factor for coronary artery disease.

OBJECTIVE

To determine the prevalence of VDD in pancreas transplant candidates, and further to examine the relationship between vitamin D and the prevalence of coronary artery disease and lipid profile parameters.

MATERIALS AND METHODS

This is a prospective cross-sectional study. We enrolled consecutive patients with type 1 diabetes eligible for simultaneous pancreas-kidney transplantation or pancreas transplant alone. The laboratory tests included HbA1c, lipid profile, creatinine, and total 25-hydroxyvitamin D (25(OH)D). The diagnosis of coronary artery disease was based on coronary angiography.

RESULTS

The study population included 48 patients. VDD was revealed in 48% of patients and coronary artery disease in 35% of patients. The mean concentration of vitamin D in the entire cohort was 21.3 ± 9.48 ng/ml. The median value of 25(OH)D in patients with coronary artery disease was significantly lower than in patients without coronary artery disease (18.5 (11.6-21.5) vs. 24.8 (18.4-31.8) ng/ml, p = 0.018). There was a significant relationship between VDD and coronary artery disease (OR = 4.36; 95% confidence interval (CI): 1.22-15.64, p = 0.034). A patient's odds of having coronary artery disease while having a sufficient level of vitamin D was 4.36 times lower than if the patient had VDD. There was a significant relationship between VDD and hypertension (OR = 5.91; 95% CI: 1.12-31.20, p = 0.039) and hemodialysis (OR = 4.25; 95% CI: 1.25-14.5, p = 0.023). There was no significant correlation between 25(OH)D and lipid profile.

CONCLUSIONS

VDD is highly prevalent in pancreas transplant candidates with type 1 diabetes. There is a significant relationship between VDD and increased prevalence of coronary disease. The lack of any significant association between serum vitamin D and lipid profile suggests that the relationship between vitamin D and coronary artery disease results from other causes.

Mechanistic Effects of Vitamin D Supplementation on Metabolic Syndrome Components in Patients with or without Vitamin D Deficiency

The prevalences of metabolic syndrome (MetS) and vitamin D deficiency are increasing dramatically worldwide. MetS is a major challenge because it can increase the risk of most non-communicable diseases. The beneficial effect of vitamin D on MetS components remains controversial, so the present review focused on the clinical effects of vitamin D supplementation on MetS components. Vitamin D can inhibit the protein expression of nuclear factor beta; improve arterial stiffness; decrease renin-angiotensin-aldosterone system activity, parathyroid hormone levels, inflammatory cytokines, 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and lanosterol 14 α-demethylase enzyme activity; increase the activity of lipoprotein lipase; alter gene expression in C2C12 cells; and improve phospholipid metabolism and mitochondrial oxidation. We tried to elucidate and analyze almost all evidence from randomized controlled trial studies of the efficacy of vitamin D supplementation in patients with MetS. The findings of the present study reported beneficial effects of vitamin D supplementation on mentioned factors. Vitamin D supplementation is recommended in people with vitamin D deficiency even if it has no considerable effect on most MetS factors. However, existing data from interventional studies are insufficient to reach a definitive conclusion about the effect of vitamin D supplementation on MetS components in patients without vitamin D deficiency. Thus, new clinical studies are needed to test the hypothesis that vitamin D supplementation could alleviate MetS components in patients with sufficient intake of vitamin D.

Exploring the effect of vitamin D3 supplementation on surrogate biomarkers of cholesterol absorption and endogenous synthesis in patients with type 2 diabetes-randomized controlled trial

BACKGROUND

Inverse associations have been reported between serum 25-hydroxyvitamin D [25(OH)D] and circulating cholesterol concentrations in observational studies. Postulated mechanisms include reduced bioavailability of intestinal cholesterol and alterations in endogenous cholesterol synthesis.

OBJECTIVE

To explore the effect of daily supplementation with 4000 IU/d vitamin D3 for 24 wk on surrogate biomarkers of cholesterol absorption (campesterol and β-sitosterol) and endogenous synthesis (lathosterol and desmosterol).

METHODS

Ancillary study of The Vitamin D for Established Type 2 Diabetes (DDM2) trial. Patients with established type 2 diabetes (N = 127, 25-75 y, BMI 23-42 kg/m2) were randomly assigned to receive either 4000 IU vitamin D3 or placebo daily for 24 wk. Of participants without changes in cholesterol-lowering medications (n = 114), plasma surrogate cholesterol absorption and endogenous synthesis biomarker concentrations were measured and merged with available measures of serum LDL cholesterol and HDL cholesterol concentrations.

RESULTS

At week 24, vitamin D3 supplementation significantly increased 25(OH)D concentrations (+21.5 ± 13.4 ng/mL) but not insulin secretion rates (primary outcome of the parent study) as reported previously. In this ancillary study there was no significant effect of vitamin D3 supplementation on serum cholesterol profile or surrogate biomarkers of cholesterol absorption and endogenous synthesis. Compared with participants not treated with cholesterol-lowering medications, those who were treated exhibited a greater reduction in plasma campesterol concentrations in the vitamin D3 but not placebo group (P-interaction = 0.011). Analyzing the data on the basis of cholesterol absorption status (hypo- versus hyperabsorbers) or cholesterol synthesis status (hypo- versus hypersynthesizers) did not alter these results.

CONCLUSIONS

Vitamin D3 supplementation for 24 wk had no significant effect on surrogate biomarkers of cholesterol absorption or endogenous synthesis, consistent with the lack of effect on serum cholesterol profile. Vitamin D3 supplementation resulted in greater reduction in campesterol concentrations in participants not using compared with those using cholesterol-lowering medications. Further studies are required.This trial was registered at clinicaltrials.gov as NCT01736865.

Low Vitamin D Serum Level Is Associated with HDL-C Dyslipidemia and Increased Serum Thrombomodulin Levels of Insulin-Resistant Individuals

BACKGROUND

Insulin-resistant individuals are known to have dyslipidemia and are predicted to be at high risk of cardiovascular events. Vitamin D deficiency was shown to be associated with dyslipidemia; however, the type of dyslipidemia associated with vitamin D deficiency in insulin-resistant individuals is not determined. Furthermore, there is evidence linking insulin resistance with low-grade inflammation suggesting levels of pro-inflammatory cytokines to be increased in insulin-resistant states.

OBJECTIVE

This study was performed to evaluate the impact of vitamin D deficiency, defined as serum level of 25(OH)D below 20 ng/mL, on lipid profile and inflammatory markers such as interleukin (IL-6) and IL-8, as well as soluble thrombomodulin (TM) in the serum of insulin-resistant individuals.

METHODS

A total of 4114 individuals had simultaneous serum 25(OH)D, insulin, and lipid panel testing during 2013 as part of the United Arab Emirates National Diabetes and Lifestyle (UAEDIAB) study. Multivariate logistic regression analysis was used to assess the association between serum level of 25(OH)D and lipid profile in insulin-sensitive versus -resistant individuals. The lipid panel was stratified into high total cholesterol (TC: >6.2 mmol/L), high low-density lipoprotein-cholesterol (LDL-C: >2.59 mmol/L), high triglycerides (TG: >2.3 mmol/L), and low high-density lipoprotein-cholesterol (HDL-C: <1.55 mmol/L) dyslipidemia. Furthermore, the immunomodulatory and vasculoprotective effects of 25(OH)D were assessed by measuring the levels of IL-6, IL-8, and soluble TM in serum using ELISA.

RESULTS

More than half of the 4114 individuals were insulin resistant (n=2760, 67%) and around one-fifth of them were vitamin D-deficient (n=796, 19%). After adjusting for age, gender, body mass index, smoking, ethnicity, and educational level, the only dyslipidemia associated with vitamin D-deficient-insulin-resistant individuals (OR 2.09 [95]; P=0.009) was lower HDL-C. Furthermore, deficient 25(OH)D individuals with low HDL-C levels had higher circulatory IL-6 and IL-8 levels, and higher serum soluble TM compared to individuals with sufficient 25(OH)D and normal lipid profiles (median, IL-6 pg/mL 0.82 vs 1.71, P=0.001; median, IL-8 pg/mL 51.31 vs 145.6, P=0.003; and median, soluble TM ng/mL 5.19 vs 7.38, P<0.0001; in sufficient vs deficient groups, respectively).

CONCLUSION

The results of our study showed that in insulin-resistant individuals, vitamin D deficiency status is associated with HDL-C dyslipidemia and higher serum inflammatory and endothelial damage markers.

The Association of Vitamin D Status with Lipid Profile and Inflammation Biomarkers in Healthy Adolescents

Background: The association between vitamin D status and inflammatory biomarkers and lipid profile is not well known, especially in adolescents. Therefore, the aim of the current study is to investigate the association of vitamin D status with serum lipids and inflammatory biomarkers, including IL-10, IL-6, hsCRP, and TNFR-2, in male adolescents. Methods and materials: A sample of seventy-one high school male students, aged 17 years old, from a high school in Tehran were enrolled in the study. They were divided into four groups including group with serum vitamin D below 25 (ng/mL) (SVD < 25; n = 36), 25 and above (ng/mL) (SVD ≥ 25; n = 35), negative-hsCRP (n = 48), and positive-hsCRP (n = 23). Weight, height, body mass index, dietary intake, serum lipids, and inflammatory biomarkers, including IL-10, IL-6, hsCRP, and TNFR-2, were measured. Results: In the (SVD < 25) group, the serum level of TNFR-2 was significantly higher compared to that in the (SVD ≥ 25) group. There was a significant negative association between serum TNFR-2 and vitamin D levels in the whole sample. We found significant lower levels of IL-10 in positive-hsCRP group compared to the negative-hsCRP group. In addition, there was a significant negative correlation between the serum vitamin D level and hsCRP in both hsCRP groups. The HDL level was lower in the (SVD < 25) group compared to that in the (SVD ≥ 25) group. Finally, there was a negative correlation between the serum HDL and hsCRP levels in the positive-hsCRP subjects. Conclusion: Based on the findings it can be concluded that serum vitamin D affects HDL and inflammation status. Although serum levels of HDL and inflammation status are both predictors of metabolic syndrome and cardiovascular disease, further studies are needed to prove it, especially in adolescents.

Effect of Vitamin D Supplementation on Lipid Profile in Vitamin D-Deficient Children with Type 1 Diabetes and Dyslipidemia

BACKGROUND

Vitamin D (VD) was suggested to have both direct and indirect effects on modifying lipid profile in patients with diabetes through its regulatory action that increases the activity of lipoprotein lipase in adiposity.

OBJECTIVES

To detect the relationship between serum 25-hydroxyvitamin D (25OHD) and lipid profiles in dyslipidemic T1D patients and study the effect of VD supplementation on lipid profiles of VD-deficient T1D patients.

METHODS

Fifty patients with T1D (for >2 years) and dyslipidemia were included. 25OHD was assessed and patients were divided accordingly into 2 groups: VD sufficiency (>30 ng/mL) and VD deficiency (VDD) or insufficiency (<29 ng/mL) who were allocated to VD3 supplementation for 4 months, then lipid profile was reevaluated in both groups.

RESULTS

Thirty patients had VDD, while 20 patients had VD sufficiency. There was no significant correlation between 25OHD and different study parameters (p > 0.05). A significant difference was found among both groups in the family history of coronary heart disease (p = 0.036) and free tetraiodothyronine 4 (p = 0.035). After 4 months of VD supplementation in VDD group, the mean difference (at 0 and 4 months) in low-density lipoproteins (LDL) and hemoglobin A1c (HbA1c) was statistically significant (p = 0.02 and 0.04 respectively) between both groups. The mean basal LDL was 126.91 mg/dL in VDD group that improved to 117.13 mg/dL after 4 months of VD therapy with a mean difference of -9.7 mg/dL compared to a mean difference of -2 mg/dL in VD sufficiency group.

CONCLUSIONS

VDD was highly prevalent in patients with T1D. There was no significant correlation between 25OHD levels and lipid profile in patients with T1D. VD supplementation for 4 months had a significant lowering effect on LDL and HbA1c.

Adequate 25-hydroxyvitamin D levels are inversely associated with various cardiometabolic risk factors in Chinese children, especially obese children

OBJECTIVE

Vitamin D deficiency has recently evolved as a major public health issue worldwide. But the relationship between vitamin D and cardiovascular health in children remains unclear. Accordingly, we aimed to examine the associations between 25-hydroxyvitamin D (25(OH)D) concentrations and cardiometabolic risk factors, and to assess the possible effect modification of obesity on the associations in a Chinese pediatric population.

RESEARCH DESIGN AND METHODS

A cross-sectional sample of 6091 children aged 6-18 years was obtained using a cluster sampling method. The 25(OH)D concentrations, and metabolic risk factors, including waist to height ratio, blood pressure, blood lipids, fasting blood glucose (FBG), and insulin were measured. Adjusted ORs and multiplicative or additive interaction were calculated to assess the associations and effect modification, respectively.

RESULTS

Triglycerides, FBG, insulin, and homeostasis model assessment of insulin resistance were inversely associated with 25(OH)D concentrations (p<0.05) in both sexes. The OR of hyperglycemia among individuals with insufficient vitamin D was higher than those with adequate vitamin D after adjusting for covariates (OR: 1.47; 95% CI 1.26 to 1.70). Moreover, girls with insufficient vitamin D had significantly higher odds for hypertension and high total cholesterol than those with adequate vitamin D, which was not observed in boys. Thirty-two percent (95% CI 14% to 51%) of the increased odds of hyperglycemia can be explained by the interaction between insufficient vitamin D and obesity.

CONCLUSIONS

Vitamin D insufficiency is associated with increased odds of various cardiometabolic risk factors in Chinese children and has a synergistic effect on hyperglycemia with obesity.

Association between standardized vitamin 25(OH)D and dyslipidemia: a community-based study in Riyadh, Saudi Arabia

BACKGROUND

Vitamin D deficiency associated with dyslipidemia can contribute towards cardiovascular diseases. Previous studies have found that Saudi Arabia has a high burden of vitamin D deficiency and cardiovascular disease risk factors. We aimed to explore the relationship between vitamin D deficiency and dyslipidemia, including total cholesterol, low-density lipids, high-density lipids (HDL), and triglycerides (TG) in apparently healthy Saudi male and female participants aged 30-75 years.

METHODS

A cross-sectional study was conducted on 1717 apparently healthy Saudi participants from 18 primary health care centers in Riyadh. Data collectors conducted the interviews, took anthropometric measurements, and collected the blood samples. Serum 25-hydroxyvitamin vitamin D (25(OH)D) levels were measured using an electrochemiluminescence assay method. Lipid panel was measured by a fully automated analyzer using enzymatic methods.

RESULTS

Multivariable logistic regression analysis revealed that the adjusted odds ratio (ORA) of low level of HDL cholesterol in association with 25(OH)D deficiency was 2.1 times higher in males (ORA = 2.1; 95% CI = 1.1, 3.9) and 1.3 times higher in females (ORA = 1.3; 95% CI = 0.9, 1.9). A significant excess odds ratio of high levels of TG in association with 25(OH) D deficiency was observed in females (ORA = 3.0; 95% CI = 1.1, 7.9) but not in males.

CONCLUSION

Vitamin D deficiency is highly prevalent in Saudi Arabia. Low levels of HDL cholesterol in men and high TG levels in women are associated with vitamin D deficiency. The results emphasize the importance of treating vitamin D deficiency in the general population.

Assessment of Subclinical Atherosclerosis in Vitamin D Deficiency

PURPOSE

Patients with vitamin D deficiency (VDD) have potential to have increased cardiovascular morbidity and mortality. In this study, we aimed to discover the findings of early atherosclerosis in patients with VDD by measuring carotid intima-media thickness (CIMT) and epicardial fat thickness (EFT).

MATERIALS AND METHODS

The study population includes 52 patients with VDD (n = 30 [57% female], mean ± SD age 54.28 ± 8.77 years, mean ± SD serum 25-hydroxyvitamin D (25 [OH] D) 11 ± 2.4 ng/mL) and 82 participants for control group (n = 52 [63.4% female], mean ± SD age 56.40 ± 7.90 years, mean ± SD serum (25 [OH] D) 53 ± 4.2 ng/mL) who have no cardiovascular disease. Carotid intima-media thickness was assessed by using ultrasonography, and EFT was measured on the free wall of the right ventricle at end diastole from the parasternal long-axis views by standard transthoracic 2-dimensional echocardiography.

RESULTS

Both CIMT and EFT were significantly higher in patients with VDD compared with controls (0.75 ± 0.16 mm vs 0.68 ± 0.21 mm, P < 0.05, and 0.66 ± 0.15 cm vs 0.56 ± 0.15 cm, P < 0.001).

CONCLUSIONS

Patients with VDD seem to have increased CIMT and EFT, which are predictors of atherosclerotic process. Further studies are needed to confirm these results.

Determinants of the magnitude of response to vitamin D supplementation in adolescent girls identified using a decision tree algorithm

Vitamin D (VitD) supplementation is an inexpensive and effective approach for improving VitD insufficiency/deficiency. However, the response to supplementation, with respect to the increase in serum 25(OH)D level varies between individuals. In this study, we have assessed the factors associated with the response to VitD supplementation using a decision-tree algorithm. Serum VitD levels, pre- and post-VitD supplementation was used as the determinant of responsiveness. The model was validated by constructing a receiver operating characteristic curve. Serum VitD at baseline levels was at the apex of the tree in our model, followed by serum low-density lipoprotein cholesterol and triglyceride, age, waist-hip ratio, and high-density lipoprotein cholesterol. Our model suggests that these determinants of responsiveness to VitD supplementation had sensitivity, specificity, and accuracy, 59.4, 75.8 and 69.3%, respectively. The decision tree model appears to be a relatively accurate, specific, and sensitive approach for identifying the factors associated with response to VitD supplementation.

Prevalence of vitamin D deficiency and associated comorbidities among Abu Dhabi Emirates population

OBJECTIVE

The study explored the prevalence of vitamin D deficiency, its seasonal variation and associated comorbidities among the Abu Dhabi Emirati population living in urban and suburban settings.

RESULT

Of the 12,346 participants 36.9% were male and 63.1% female. The majority (72%) were either vitamin D deficient (< 50 nmol/L), or (10%) vitamin D insufficient (50-74 nmol/L). Vitamin D deficiency was similar in both sexes (male 83.1% vs female 83.8%) as insufficiency (male 12.7% vs female 11.2%). Low vitamin D levels were associated with high blood pressure, high body mass index, central obesity, high cholesterol, impaired blood glucose levels and a high Framingham risk score. The mean vitamin D level was highest in January (winter) and lowest in July (summer).

Vitamin D deficiency is associated with dyslipidemia: a cross-sectional study in 3788 subjects

BACKGROUND

Previously we reported on severe vitamin D deficiency in a large-scale cohort in the Tangshan area in northern China. However, whether vitamin D deficiency is associated with cardiovascular risk factors has not been systematically examined in the cohort.

OBJECTIVE

We aimed to determine the correlation between serum vitamin D status and lipid levels in circulation via an observational study.

METHODS

Serum 25-hydroxyvitamin D (25[OH]D) was measured. Based on the measurement subjects were classified into quintiles. Dyslipidemia was defined as having one of the following: elevated serum total cholesterol, LDL cholesterol, triglycerides or decreased HDL cholesterol, under lipid-control treatment.

RESULTS

The study was conducted in a total of 3788 adults in northern China during their routine health examinations. When the highest quintile of the 25(OH)D level was set as reference, the risk of having dyslipidemia increased progressively across the highest to the lowest 25(OH)D with ORs of 1 (reference), 1.232 (95% CI, 1.005-1.509), 1.235 (95% CI, 1.007-1.513), 1.403 (95% CI, 1.143-1.735) and 1.494 (95% CI, 1.217-1.833), respectively (P_trend < .0001) after adjustment for age. This trend was unchanged after further adjustment for several potential confounders. In linear regression analysis, we found an inverse significant correlation between 25(OH)D and triglycerides (β coefficient = -0.077, p < .05) and LDL cholesterol (β coefficient = -0.245, p < .05), and positive correlation with HDL cholesterol (β coefficient = 0.038, p = .018).

CONCLUSION

Vitamin D deficiency is found to be associated with dyslipidemia in a cohort of 3788 subjects. Specifically, serum 25(OH)D is inversely correlated with LDL cholesterol and triglycerides levels, and positively correlated with HDL cholesterol level.

Vitamin D and Atherosclerotic Cardiovascular Disease

CONTEXT

A large body of experimental and observational data has implicated vitamin D deficiency in the development of cardiovascular disease. However, evidence to support routine vitamin D supplementation to prevent or treat cardiovascular disease is lacking.

EVIDENCE ACQUISITION

A comprehensive literature review was performed using Pubmed and other literature search engines.

EVIDENCE SYNTHESIS

Mounting epidemiological evidence and data from Mendelian randomization studies support a link between vitamin D deficiency and adverse cardiovascular health outcomes, but randomized trial evidence to support vitamin D supplementation is sparse. Current public health guidelines restrict vitamin D intake recommendations to the maintenance of bone health and prevention of fractures. Two recently published large trials (VITAL and ViDA) that assessed the role of moderate-to-high dose vitamin D supplementation as primary prevention for cardiovascular outcomes in the general population had null results, and previous randomized trials have also been generally negative. These findings from general population cohorts that are largely replete in vitamin D may not be applicable to chronic kidney disease (CKD) populations, in which the use of active (1α-hydroxylated) vitamin D compounds is prevalent, or to other high-risk populations. Additionally, recent trials in the CKD population, and trials using vitamin D analogues have been limited.

CONCLUSIONS

Current randomized trials of vitamin D supplementation do not support benefits for cardiovascular health, but the evidence remains inconclusive. Additional randomized trials assessing larger numbers of participants with low baseline vitamin D levels, having longer follow-up periods, and testing higher vitamin D dosages, are needed to guide clinical practice.

The effect of chronic oral vitamin D supplementation on adiposity and insulin secretion in hypothalamic obese rats

Reduced plasma vitamin D (VD) levels may contribute to excessive white adipose tissue, insulin resistance (IR) and dyslipidaemia. We evaluated the effect of chronic oral VD supplementation on adiposity and insulin secretion in monosodium glutamate (MSG)-treated rats. During their first 5 d of life, male neonate rats received subcutaneous injections of MSG (4 g/kg), while the control (CON) group received saline solution. After weaning, groups were randomly distributed into VD supplemented (12 µg/kg; three times/week) and non-supplemented (NS) rats, forming four experimental groups (n 15 rats/group): CON-NS, CON-VD, MSG-NS and MSG-VD. At 76 d of life, rats were submitted to an oral glucose tolerance test (OGTT; 2 g/kg), and at 86 d, obesity, IR and plasma metabolic parameters were evaluated. Pancreatic islets were isolated for glucose-induced insulin secretion (GIIS), cholinergic insulinotropic response and muscarinic 3 receptor (M3R), protein kinase C (PKC) and protein kinase A (PKA) expressions. Pancreas was submitted to histological analyses. VD supplementation decreased hyperinsulinaemia (86 %), hypertriacylglycerolaemia (50 %) and restored insulin sensibility (89 %) in MSG-VD rats, without modifying adiposity, OGTT or GIIS, compared with the MSG-NS group. The cholinergic action was reduced (57 %) in islets from MSG-VD rats, without any change in M3R, PKA or PKC expression. In conclusion, chronic oral VD supplementation of MSG-obese rats was able to prevent hyperinsulinaemia and IR, improving triacylglycerolaemia without modifying adiposity. A reduced cholinergic pancreatic effect, in response to VD, could be involved in the normalisation of plasma insulin levels, an event that appears to be independent of M3R and its downstream pathways.

Obesity and dyslipidemia

Obesity, a pandemic of the modern world, is intimately associated with dyslipidemia, which is mainly driven by the effects of insulin resistance and pro-inflammatory adipokines. However, recent evidence suggests that obesity-induced dyslipidemia is not a unique pathophysiological entity, but rather has distinct characteristics depending on many individual factors. In line with that, in a subgroup of metabolically healthy obese (MHO) individuals, dyslipidemia is less prominent or even absent. In this review, we will address the main characteristics of dyslipidemia and mechanisms that induce its development in obesity. The fields, which should be further investigated to expand our knowledge on obesity-related dyslipidemia and potentially yield new strategies for prevention and management of cardiometabolic risk, will be highlighted. Also, we will discuss recent findings on novel lipid biomarkers in obesity, in particular proprotein convertase subtilisin/kexin type 9 (PCSK9), as the key molecule that regulates metabolism of low-density lipoproteins (LDL), and sphingosine-1-phosphate (S1P), as one of the most important mediators of high-density lipoprotein (HDL) particles function. Special attention will be given to microRNAs and their potential use as biomarkers of obesity-associated dyslipidemia.

Effects of vitamin D supplementation along with endurance physical activity on lipid profile in metabolic syndrome patients: A randomized controlled trial

BACKGROUND AND OBJECTIVES

This study was conducted to determine the effects of vitamin D supplementation along with endurance physical activity on lipid profile among metabolic syndrome patients.

MATERIALS AND METHODS

In a parallel randomized placebo controlled trial, 70 metabolic syndrome patients, were randomly assigned into three groups. Biochemical tests were assessed as baseline and after 12 weeks of intervention. Statistical analysis was performed using SPSS version 20.

RESULTS

The mean vitamin D levels was increased significantly in both vitamin D and vitamin D plus physical activity groups (P value < 0.05). No significant change was observed in the placebo group. Additionally, there was a significant decrease in total cholesterol and LDL-C in vitamin D plus physical activity group (P value < 0.05). No significant differences in changes of triglycerides and HDL-C among the three groups (P value > 0.05). While, in vitamin D group a decreased in total cholesterol, HDL-C, LDL-C and increase in triglycerides were observed, but did not reach a statistically significant.

CONCLUSION

Daily supplementation of vitamin D for 12 weeks, along with moderate endurance physical activity, significantly increase vitamin D concentration and induce a significant reduction in lipid profile in metabolic syndrome patients.

Vitamin D Receptor Polymorphism and DHCR7 Contribute to the Abnormal Interplay Between Vitamin D and Lipid Profile in Rheumatoid Arthritis

Emerging evidence suggests a role for 7-dehydrocholesterol reductase (DHCR7) in the crosstalk between cholesterol and vitamin D. Our aim was to evaluate the impact of vitamin D-related polymorphisms and DHCR7 levels in the association between vitamin D deficiency and altered lipid profile in rheumatoid arthritis (RA). Serum 25(OH)-vitamin D, DHCR7 levels and vitamin D-related polymorphisms (VDR-rs2228570, CYP27A1-rs933994, CYP2R1-rs10741657 and DHCR7-rs12785878) were analyzed in 211 RA patients,94 controls and in a prospective cohort of 13 RA patients undergoing TNFα-blockade. Vitamin D was decreased in RA (p < 0.001), correlated to HDL-cholesterol (r = 0.217, p < 0.001) and total-/HDL-cholesterol ratio (r = -0.227, p = 0.004). These correlations were restricted to the VDR-rs2228570 status. Vitamin D deficiency was associated with lower HDL-cholesterol (p = 0.028), higher tender (p = 0.005) and swollen (p = 0.002) joint counts, higher DAS28 (p = 0.018) and HAQ (p = 0.024) in AG/AA-patients but not in their GG-counterparts. The associations among DHCR7, vitamin D and lipid profile followed a seasonal pattern, decreased DHCR7 (p = 0.008) and vitamin D (p < 0.001) and increased total-cholesterol (p = 0.025) being found in winter/spring. Increasing vitamin D upon TNFα-blockade paralleled RA clinical improvement (r = -0.610, p = 0.027) and DHCR7 elevation (r = 0.766, p = 0.002). In conclusion, vitamin D-related polymorphisms and DHCR7 are pivotal to understand the complex, seasonal associations between vitamin D and lipid profile in RA.

Comprehensive Review on Diabetes Associated Cardiovascular Complications - The Vitamin D Perspective

Vitamin D, a steroid hormone is primarily known for its role in calcium and bone mineral homeostasis. Over the years, vitamin D has been implicated in various non-skeletal diseases. The extraskeletal phenomenon can be attributed to the presence of vitamin D receptors (VDRs) in almost all cells and identification of 1-α hydroxylase in extrarenal tissues. The vitamin D deficiency (VDD) pandemic was globally reported with increasing evidence and paralleled the prevalence of diabetes, obesity and cardiovascular diseases (CVDs). A dependent link was proposed between hypovitaminosis D glycemic status, insulin resistance and also the other major factors associated with type 2 diabetes leading to CVDs. Insulin resistance plays a central role in both type 2 diabetes and insulin resistance syndrome. These 2 disorders are associated with distinct etiologies including hypertension, atherogenic dyslipidemia, and significant vascular abnormalities that could lead to endothelial dysfunction. Evidence from randomised clinical trials and meta-analysis, however, yielded conflicting results. This review summarizes the role of vitamin D in the regulation of glucose homeostasis with an emphasis on insulin resistance, blood pressure, dyslipidaemia, endothelial dysfunction and related cardiovascular diseases and also underline the plausible mechanisms for all the documented effects.

Potential causal associations of serum 25-hydroxyvitamin D with lipids: a Mendelian randomization approach of the HUNT study

Observational studies have shown consistent associations between higher circulating 25-hydroxyvitamin D [25(OH)D] levels and favorable serum lipids. We sought to investigate if such associations were causal. A Mendelian randomization (MR) study was conducted on a population-based cohort comprising 56,435 adults in Norway. A weighted 25(OH)D allele score was generated based on vitamin D-increasing alleles of rs2282679, rs12785878 and rs10741657. Linear regression analyses of serum lipid levels on the allele score were performed to assess the presence of causal associations of serum 25(OH)D with the lipids. To quantify the causal effects, the inverse-variance weighted method was used for calculating MR estimates based on summarized data of individual single-nucleotide polymorphisms. The MR estimate with 95% confidence interval (CI) represents percentage difference in the lipid level per genetically determined 25 nmol/L increase in 25(OH)D. The 25(OH)D allele score demonstrated a clear association with high-density lipoprotein (HDL) cholesterol (p = 0.007) but no association with total or non-HDL cholesterol or triglycerides (p ≥ 0.27). The MR estimate showed 2.52% (95% CI 0.79-4.25%) increase in HDL cholesterol per genetically determined 25 nmol/L increase in 25(OH)D, which was stronger than the corresponding estimate of 1.83% (95% CI 0.85-2.81%) from the observational analysis. The MR estimates for total cholesterol (0.60%, 95% CI - 0.73 to 1.94%), non-HDL cholesterol (0.04%, 95% CI - 1.79 to 1.88%) and triglycerides (- 2.74%, 95% CI - 6.16 to 0.67%) showed no associations. MR analysis of data from a population-based cohort suggested a causal and positive association between serum 25(OH)D and HDL cholesterol.

Calcitriol combined with calcium chloride causes apoptosis in undifferentiated adipose tissue-derived human mesenchymal stem cells, but this effect decreases during adipogenic differentiation

Calcitriol, the bioactive hormone of vitamin D, is currently linked to several diseases, such as obesity and gain of adipose mass, due to its liposolubility and, consequently, its sequestration by adipocytes. As rates of obesity continue to increase, research on the biology of weight gain should be encouraged. This study evaluated the effects of calcitriol combined with CaCl₂ on adipose tissue-derived human mesenchymal stem cells. We evaluated the cytotoxicity of the combination by MTT assays, in which undifferentiated cells and cells undergoing adipogenic differentiation were tested for 7 and 14 days. The results demonstrated that the combination of calcitriol at the IC₅₀ and CaCl₂ at the IC₂₀ was effective at reducing the viability of mesenchymal stem cells, but with the progression of cell differentiation towards adipocytes, cell resistance to the cytotoxic effects increased. The percentages of dead cells were 88.29, 57.45 and 28.81% for undifferentiated cells and cells exposed to differentiation medium for 7 and 14 days, respectively. Undifferentiated cells were evaluated for apoptosis in response to the same combination using Annexin V assays, and a possible onset of programmed cell death in undifferentiated cells was detected. Additionally, the combination of the compounds altered the membrane permeability of undifferentiated cells by 16 percentage points and induced cell cycle arrest in S phase due to the accumulation of damage. An evaluation of gene expression revealed the overexpression of the GADD45 and ATM genes and the underexpression of the P21, P53, ATR, BCL-2, EIF2 AK3, IGF1R, DNAse-2, ATF, MAP3K4, ENGO-G, CASP3, CASP7 and CASP8 genes. Our results provide valuable insights into the biology of obesity and may contribute to the development of new anti-obesity therapies focusing on the inhibition of adipose tissue mesenchymal stem cell hyperplasia and adipogenic differentiation.