Atorvastatin increases 25-hydroxy vitamin D concentrations in patients with polycystic ovary syndrome

Statins for women with polycystic ovary syndrome not actively trying to conceive

BACKGROUND

Statins are lipid-lowering agents with pleiotropic actions. Experts have proposed that in addition to improving the dyslipidaemia associated with polycystic ovary syndrome (PCOS), statins may also exert other beneficial metabolic and endocrine effects, such as reducing testosterone levels. This is an update of a Cochrane Review first published in 2011.

OBJECTIVES

To assess the efficacy and safety of statin therapy in women with PCOS who are not actively trying to conceive.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHLs, and four ongoing trials registers on 7 November 2022. We also handsearched relevant conference proceedings and the reference lists of relevant trials for any additional studies, and we contacted experts in the field for any further ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated the effects of statin therapy in women with PCOS not actively trying to conceive. Eligible comparisons were statin versus placebo or no treatment, statin plus another agent versus the other agent alone, and statin versus another agent. We performed statistical analysis using Review Manager 5, and we assessed the certainty of the evidence using GRADE methods.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Our primary outcomes were resumption of menstrual regularity and resumption of spontaneous ovulation. Our secondary outcomes were clinical and physiological measures including hirsutism, acne severity, testosterone levels, and adverse events.

MAIN RESULTS

Six RCTs fulfilled the criteria for inclusion. They included 396 women with PCOS who received six weeks, three months, or six months of treatment; 374 women completed the studies. Three studies evaluated the effects of simvastatin and three studies evaluated the effects of atorvastatin. We summarised the results of the studies under the following comparisons. Statins versus placebo (3 RCTs) One trial measured resumption of menstrual regularity as menstrual cycle length in days. We are uncertain if statins compared with placebo shorten the mean length of the menstrual cycle (mean difference (MD) -2.00 days, 95% confidence interval (CI) -24.86 to 20.86; 37 participants; very low-certainty evidence). No studies reported resumption of spontaneous ovulation, improvement in hirsutism, or improvement in acne. We are uncertain if statins compared with placebo reduce testosterone levels after six weeks (MD 0.06, 95% CI -0.72 to 0.84; 1 RCT, 20 participants; very low-certainty evidence), after 3 months (MD -0.53, 95% CI -1.61 to 0.54; 2 RCTs, 64 participants; very low-certainty evidence), or after 6 months (MD 0.10, 95% CI -0.43 to 0.63; 1 RCT, 28 participants; very low-certainty evidence) Two studies recorded adverse events, and neither reported significant differences between the groups. Statins plus metformin versus metformin alone (1 RCT) The single RCT included in this comparison measured resumption of menstrual regularity as the number of spontaneous menses per six months. We are uncertain if statins plus metformin compared with metformin improves resumption of menstrual regularity (MD 0.60 menses, 95% CI 0.08 to 1.12; 69 participants; very low-certainty evidence). The study did not report resumption of spontaneous ovulation. We are uncertain if statins plus metformin compared with metformin alone improves hirsutism measured using the Ferriman-Gallwey score (MD -0.16, 95% CI -0.91 to 0.59; 69 participants; very low-certainty evidence), acne severity measured on a scale of 0 to 3 (MD -0.31, 95% CI -0.67 to 0.05; 69 participants; very low-certainty evidence), or testosterone levels (MD -0.03, 95% CI -0.37 to 0.31; 69 participants; very low-certainty evidence). The study reported that no significant adverse events occurred. Statins plus oral contraceptive pill versus oral contraceptive pill alone (1 RCT) The single RCT included in this comparison did not report resumption of menstrual regularity or spontaneous ovulation. We are uncertain if statins plus the oral contraceptive pill (OCP) improves hirsutism compared with OCP alone (MD -0.12, 95% CI -0.41 to 0.17; 48 participants; very low-certainty evidence). The study did not report improvement in acne severity. We are also uncertain if statins plus OCP compared with OCP alone reduces testosterone levels, because the certainty of the evidence was very low (MD -0.82, 95% CI -1.38 to -0.26; 48 participants). The study reported that no participants experienced significant side effects. Statins versus metformin (2 RCTs) We are uncertain if statins improve menstrual regularity compared with metformin (number of spontaneous menses per six months) compared to metformin (MD 0.50 menses, 95% CI -0.05 to 1.05; 1 RCT, 61 participants, very low-certainty evidence). No studies reported resumption of spontaneous ovulation. We are uncertain if statins compared with metformin reduce hirsutism measured using the Ferriman-Gallwey score (MD -0.26, 95% CI -0.97 to 0.45; 1 RCT, 61 participants; very low-certainty evidence), acne severity measured on a scale of 0 to 3 (MD -0.18, 95% CI -0.53 to 0.17; 1 RCT, 61 participants; very low-certainty evidence), or testosterone levels (MD -0.24, 95% CI -0.58 to 0.10; 1 RCT, 61 participants; very low-certainty evidence). Both trials reported that no significant adverse events had occurred. Statins versus oral contraceptive pill plus flutamide (1 RCT) According to the study report, no participants experienced any significant side effects. There were no available data for any other main outcomes.

AUTHORS' CONCLUSIONS

The evidence for all main outcomes of this review was of very low certainty. Due to the limited evidence, we are uncertain if statins compared with placebo, or statins plus metformin compared with metformin alone, improve resumption of menstrual regularity. The trial evaluating statin plus OCP versus OCP alone reported neither of our primary outcomes. No other studies reported resumption of spontaneous ovulation. We are uncertain if statins improve hirsutism, acne severity, or testosterone. All trials that measured adverse events reported no significant differences between the groups.

miR-206 serves an important role in polycystic ovary syndrome through modulating ovarian granulosa cell proliferation and apoptosis

An increasing number of studies have reported that microRNAs (miRNAs) have an important role in polycystic ovary syndrome (PCOS). Downregulation of miR-206 in patients with PCOS has been found, however, its specific role remains unclear. The present study aimed to investigate the roles of miR-206 in (PCOS) and to determine the underlying molecular mechanisms. Reverse transcription-quantitative PCR (RT-qPCR) was performed to analyze the expression levels of miR-206 in normal ovarian surface epithelial IOSE80 cells and human ovarian granulosa cell-like KGN cells. TargetScan was used to predict the target gene of miR-206, which was subsequently verified using a dual-luciferase reporter gene assay. The mRNA expression levels of cyclin D2 (CCND2) and the transfection efficiencies of the miR-206 mimic and CCDN2 overexpression plasmid were determined using RT-qPCR analysis. The protein expression levels of CCND2, cleaved-caspase-3 and pro-caspase-3 were analyzed using western blotting, and an MTT assay and flow cytometric analysis were used to evaluate the cell viability and levels of apoptosis, respectively, in the cells following transfection. Finally, the activity of caspase-3 was analyzed using a caspase-3 activity assay kit. The results of the present study revealed that the expression levels of miR-206 were downregulated in KGN cells compared with IOSE80 cells. CCND2 was predicted and verified to be a direct target gene of miR-206, and the mRNA and protein expression levels of CCND2 were discovered to be upregulated in KGN cells compared with IOSE80 cells. The miR-206 mimic and CCND2 overexpression plasmid significantly upregulated the expression levels of miR-206 and CCND2, respectively, in KGN cells. The miR-206 mimic also downregulated the expression levels of CCND2 in KGN cells, while this effect was reversed following the transfection with the CCND2 overexpression plasmid. Compared with the mimic control group, the miR-206 mimic significantly decreased the cell viability, induced the levels of apoptosis, increased the activity of caspase-3, upregulated cleaved-caspase-3 protein expression levels and downregulated pro-caspase-3 protein expression levels in KGN cells following transfection; these effects were reversed following the overexpression of CCND2. In conclusion, the findings of the present study suggested that miR-206 may serve an important role in PCOS through modulating ovarian granulosa cell viability and apoptosis.

To study impact of treatment with Rosuvastatin versus Atorvastatin on 25 hydroxy Vitamin D concentrations among adult Indian men- a randomized control trial

BACKGROUND

Dyslipidemias are on the rise and are increasingly being treated with statins. As the metabolism of cholecalciferol and cholesterol are interrelated, reduction in cholesterol synthesis by statins is likely to affect Vitamin D status.

OBJECTIVES

(1) The aim is to study the effect of treatment with statins (Atorvastatin/Rosuvastatin) on 25-hydroxy-Vitamin-D (25OHD) among newly detected subjects with dyslipidemia for 6 months (2) To study the impact of 25OHD concentrations on the efficacy of statin treatment.

MATERIALS AND METHODS

This was a prospective, balanced randomized (1:1), open-label, parallel-group study, in apparently healthy Indian adult men (south Asian, 40-60 years). At baseline, serum lipids and 25OHD concentrations were measured. Based on the Adult Treatment Panel III guidelines, subjects were divided as per lipid concentrations into controls (who did not require statin treatment) and intervention (who required statin treatment) groups. Random allocation of subjects was done in two groups for receiving intervention for 6 months: Atorvastatin group (n = 52, received Atorvastatin) or Rosuvastatin group (n = 52, received Rosuvastatin). Lipids and 25OHD concentrations were measured at the end line.

RESULTS

Atorvastatin group presented significant reduction (P < 0.05) in 25OHD, total cholesterol (TC) and low-density-lipoprotein-cholesterol (LDL-C) concentrations at the end line. In the Rosuvastatin group, significant drop in TC, LDL-C and high-density lipoprotein cholesterol (concentrations (P < 0.05) was observed, while 25OHD concentrations showed no significant change. Mean 25OHD concentrations were significantly correlated with a reduction in LDL-C concentrations in Atorvastatin group.

CONCLUSIONS

Treatment with Atorvastatin resulted in a reduction in 25OHD concentrations; further, its efficacy in reducing LDL-C concentrations was related to the 25OHD concentrations.

Dyslipidemia involvement in the development of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is widely accepted as the most common endocrine abnormality in women of childbearing age and may be accompanied by dyslipidemia, hyperandrogenism, hyperinsulinemia, oxidative stress and infertility. Dyslipidemia is now known to play an important role in the development of PCOS. Lipid abnormalities, including elevated low-density lipoprotein and triglyceride levels and reduced high-density lipoprotein levels, are often found in women with PCOS and play an important role in PCOS; therefore, we summarize the effect of lipid abnormalities on hyperandrogenism, insulin resistance, oxidative stress and infertility in PCOS and review the effects of common lipid-lowering drugs on patients with PCOS. The purpose of this article is to elucidate the mechanisms of lipid metabolism abnormalities in the development of PCOS.

A Randomized, Controlled Trial of Vitamin D Supplementation on Cardiovascular Risk Factors, Hormones, and Liver Markers in Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) increases the risk of metabolic syndrome and non-alcoholic-fatty-liver disease (NAFLD). Vitamin D supplementation may exert positive effects on liver biochemistry in patients with NAFLD; however, its effects on PCOS are unknown. This randomized, double-blind, placebo-controlled study explored the effect of vitamin D supplementation on cardiovascular risk factors (high-sensitivity C-reactive protein (hs-CRP), weight, body mass index (BMI), lipid profile, glucose levels, insulin levels, the homeostatic model assessment-insulin resistance (HOMA-IR), hormones (free androgen index (FAI), testosterone, sex hormone binding globulin (SHBG), and liver markers (alanine aminotransferase (ALT), hyaluronic acid (HA), N-terminal pro-peptide of type III procollagen (PIIINP), tissue inhibitor of metallo-proteinases-1 (TIMP-1), and the enhanced liver fibrosis (ELF) score). Forty women with PCOS were recruited and randomized to vitamin D (3200 IU) or placebo daily for 3 months. All outcomes were measured at baseline and 3 months follow-up (FU). Greater increases in vitamin D levels were shown in the supplementation group (vitamin D, baseline: 25.6 ± 11.4 nmol/L, FU: 90.4 ± 19.5 nmol/L vs. placebo, baseline: 30.9 ± 11.1 nmol/L, FU: 47.6 ± 20.5 nmol/L, p < 0.001). Between groups comparisons (% baseline change) revealed significant differences in ALT (p = 0.042) and a weak effect indicating a greater reduction in the HOMA-IR in the vitamin D group (p = 0.051). No further between group differences were seen in other cardiovascular risk factor, liver markers, or hormones. This study supports beneficial effects of vitamin D supplementation on liver markers and modest improvements in insulin sensitivity in vitamin D deficient women with PCOS.

Early Effects of Atorvastatin on Vitamin D and Parathyroid Hormone Serum Levels Following Acute Myocardial Infarction

Objective:

High Vitamin D serum level after acute myocardial infarction (aMI) has shown to increase cardiac reconstruction by increasing cell survival and enhancing angiogenesis. Atorvastatin has a well-defined role in both primary and secondary prevention of cardiovascular diseases. It is suggested that this effect may partly be attributable to raising 25-hydroxyvitamin D concentrations. The aim of this study was to evaluate atorvastatin effects on Vitamin D and parathyroid hormone (PTH) levels early after aMI.

Methods:

All patients admitted with aMI in Imam Reza Hospital, Mashhad, Iran, from July 2014 to March 2015, were included in this pre- and postintervention study. Serum levels of Vitamin D and PTH were measured on admission and the 3^rd day after administration of atorvastatin 80 mg/day.

Findings:

A total of 69 post-aMI patients (47 males and 22 females) were enrolled in this study. Serum levels of Vitamin D and PTH were significantly higher (23.52 ng/ml and 46.04 pg/ml, respectively) after 72 h of atorvastatin therapy compared to the baseline (19.66 ng/ml and 31.19 pg/ml, respectively) (P = 0.004 and 0.002, respectively).

Conclusion:

The early post-aMI beneficial effects of atorvastatin can be attributed to increased serum Vitamin D level; however, atorvastatin cannot significantly decrease serum PTH level after aMI. Further studies are needed to elucidate the clinical effect of atorvastatin.

Evidence of Drug-Nutrient Interactions with Chronic Use of Commonly Prescribed Medications: An Update

The long-term use of prescription and over-the-counter drugs can induce subclinical and clinically relevant micronutrient deficiencies, which may develop gradually over months or even years. Given the large number of medications currently available, the number of research studies examining potential drug-nutrient interactions is quite limited. A comprehensive, updated review of the potential drug-nutrient interactions with chronic use of the most often prescribed medications for commonly diagnosed conditions among the general U.S. adult population is presented. For the majority of the interactions described in this paper, more high-quality intervention trials are needed to better understand their clinical importance and potential consequences. A number of these studies have identified potential risk factors that may make certain populations more susceptible, but guidelines on how to best manage and/or prevent drug-induced nutrient inadequacies are lacking. Although widespread supplementation is not currently recommended, it is important to ensure at-risk patients reach their recommended intakes for vitamins and minerals. In conjunction with an overall healthy diet, appropriate dietary supplementation may be a practical and efficacious way to maintain or improve micronutrient status in patients at risk of deficiencies, such as those taking medications known to compromise nutritional status. The summary evidence presented in this review will help inform future research efforts and, ultimately, guide recommendations for patient care.

Therapeutic Roles of Statins in Gynecology and Obstetrics: The Current Evidence

INTRODUCTION

Statins are a class of drugs, which act by inhibiting the rate-limiting enzyme of cholesterol biosynthesis (3-hydroxy-3-methyl-glutaryl-CoA reductase). The inhibition of mevalonate synthesis leads to subsequent inhibition of downstream products of this pathway, which explains the pleiotropic effects of these agents in addition to their well-known lipid-lowering effects. Accumulating evidence suggests that statins might be beneficial in various obstetric and gynecologic conditions.

METHODS

Literature searches were performed in PubMed and EMBASE for articles with content related to statins in obstetrics and gynecology. The findings are hereby reviewed and discussed.

RESULTS

Inhibition of mevalonate pathway leads to subsequent inhibition of downstream products such as geranyl pyrophosphate, farnesyl pyrophosphate, and geranylgeranyl pyrophosphate. These products are required for proper intracellular localization of several proteins, which play important roles in signaling pathways by regulating membrane trafficking, motility, proliferation, differentiation, and cytoskeletal organization. The pleiotropic effects of statins can be summarized in 4 categories: antiproliferative, anti-invasive, anti-inflammatory, and antiangiogenic. The growing body of evidence is promising for these agents to be beneficial in endometriosis, polycystic ovary syndrome, adhesion prevention, ovarian cancer, preeclampsia, and antiphospholipid syndrome. Although in vivo studies showed varying degrees of benefit on fibroids and preterm birth, appropriately designed clinical trials are needed to make definitive conclusions.

CONCLUSION

Statins might play a role in the treatment of endometriosis, polycystic ovary syndrome, adhesion prevention, ovarian cancer, preeclampsia, and antiphospholipid syndrome.

Baseline Vitamin D Deficiency Decreases the Effectiveness of Statins in HIV-Infected Adults on Antiretroviral Therapy

OBJECTIVE

Vitamin D deficiency is common in HIV. Statins may increase vitamin D, and it is unknown whether vitamin D modifies the effect of statins on cardiovascular disease.

DESIGN

SATURN-HIV was a 96-week, randomized, placebo-controlled trial designed to evaluate the effect of rosuvastatin on immune activation and subclinical vascular disease in HIV-infected adults on antiretroviral therapy. This analysis focuses on the prespecified secondary endpoint 25-hydroxyvitamin D [25(OH)D] concentrations.

METHODS

Mixed effects linear modeling and analysis of variance were used to assess the rosuvastatin effect on plasma 25(OH)D concentrations over time and to determine whether baseline vitamin D modifies the rosuvastatin effect on changes in outcomes over the trial.

RESULTS

Hundred forty-seven adults were randomized (72 to rosuvastatin and 75 to placebo); 78% were men, 68% African American, with a mean age of 45 years. Baseline 25(OH)D concentrations were similar (overall mean 18 ng/mL) with 65% of participants below 20 ng/mL. Changes in 25(OH)D at 96 weeks were small and not significant within- or between-rosuvastatin and placebo groups. There were significant group by vitamin D status interactions for changes in low-density lipoprotein-cholesterol, proportion of patrolling monocytes expressing tissue factor (CD14dimCD16+TF+), lipoprotein-associated phospholipase A2, and common carotid artery intima media thickness at most time points. For each of these outcomes, the beneficial effects of rosuvastatin were either not apparent or attenuated in participants with 25(OH)D <20 ng/mL.

CONCLUSIONS

Although 25(OH)D did not change with rosuvastatin, baseline vitamin D deficiency decreased the effectiveness of rosuvastatin. Vitamin D supplementation may be warranted for deficient patients initiating statin therapy.

Statin Use and 25-Hydroxyvitamin D Blood Level Response to Vitamin D Treatment of Older Adults

OBJECTIVES

To determine whether statin use alters response of 25-hydroxyvitamin D (25(OH)D) level to vitamin D treatment.

DESIGN

Pooled analysis.

SETTING

Three double-blind randomized controlled trials that tested different doses of vitamin D.

PARTICIPANTS

Participants of three trials (N = 646; mean age 76.3 ± 8.4, 65% female).

MEASUREMENTS

In all three trials, 25(OH)D status and statin use were assessed repeatedly over time (baseline, 6 and 12 months). Repeated-measures analysis was used to compare 25(OH)D response to vitamin D treatment at baseline and 6 and 12 months of statin users and nonusers, controlling for age, sex, body mass index, Charlson Comorbidity Index, vitamin D dose, trial, and season.

RESULTS

At baseline, 17.5% were statin users, and 65% were vitamin D deficient (25(OH)D < 20 ng/mL). Baseline 25(OH)D levels did not differ significantly between groups at baseline (18.8 for statin users, 17.2 ng/mL for nonusers, P = .07), but according to the longitudinal analyses, the total increase over 12 months in 25(OH)D concentration was significantly lower in statin users (13.1 ng/L) than nonusers (15.9 ng/mL; 21.4% difference; P = .009).

CONCLUSION

Of persons aged 60 and older at high risk of vitamin D deficiency, statin users had a 21.4% smaller increase in 25(OH)D serum concentrations over time than nonusers, independent of vitamin D dose and other covariates.

Effect of statins on serum vitamin D concentrations: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to assess the effects of statin therapy on serum vitamin D concentrations.

MATERIALS AND METHODS

We searched multiple databases including PubMed, MEDLINE, Web of Science and Google Scholar from inception to May 2016, for studies on the effects of statin treatment on serum vitamin D concentration. Quantitative data synthesis used random-effects models meta-analysis, with sensitivity analysis conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I² index. The systematic review's registration number was CRD42016035974.

RESULTS

In all, seven of 644 studies met our selection criteria including three randomized controlled trials (RCT), three observational cohort studies and one case-control study. Across RCTs, treatment with statins was associated a significant increase in serum vitamin D concentrations [weighted mean difference (WMD) 2·71 ng/mL, 95% CI 0·19-5·24, I² 62·1%). Across studies of non-RCT design, statins treatment was associated with a decrease in vitamin D concentrations (WMD -0·70 ng/mL, 95% CI -1·20 to -0·20, I² 56·3%). These findings were robust in sensitivity analyses.

CONCLUSIONS

This meta-analysis was inconclusive on the effects of statins on vitamin D, with conflicting directions of the effects from interventional and observational studies. The suggested favourable effects from RCTs need to be confirmed in larger studies with extended follow-up in order to determine the possible health benefits.

Multiple Sclerosis: Implications of Obesity in Neuroinflammation

Since the discovery of the remarkable properties of adipose tissue as a metabolically active organ, several evidences on the possible link between obesity and the pathogenesis of multiple sclerosis (MS) have been gathered. Obesity in early life, mainly during adolescence, has been proposed as a relevant risk factor for late MS development. Moreover, once MS is initiated, obesity can contribute to increase disease severity by negatively influencing disease progress. Despite the fact that clinical data are not yet conclusive, many biochemical links have been recently disclosed. The "low-grade inflammation" that characterizes obesity can lead to neuroinflammation through different mechanisms, including choroid plexus and blood-brain barrier disruption. Furthermore, it is well known that resident immune cells of central nervous system and peripheral immune cells are involved in the pathogenesis of MS, and adipokines and neuropeptides such as neuropeptide Y may mediate the cross talk between them.

Vitamin D deficiency as adverse drug reaction? A cross-sectional study in Dutch geriatric outpatients

PURPOSE

Adverse drug reactions as well as vitamin D deficiency are issues of public health concern in older people. However, relatively little is known about the impact of drug use on vitamin D status. Our primary aim is to explore associations between drug use and vitamin D status in older people. Furthermore, prevalences of drug use and vitamin D deficiency are estimated.

METHODS

In a population of 873 community-dwelling Dutch geriatric outpatients, we explored the cross-sectional relationships of polypharmacy (≥5 medications concomitantly used), severe polypharmacy (≥10 medications), and use of twenty-one specific drug groups, with serum 25-hydroxyvitamin D (25(OH)D) by analysis of covariance.

RESULTS

Overall prevalence of polypharmacy was 65 %, of severe polypharmacy 22 %. Depending on the cut-off value, prevalence of vitamin D deficiency was 49 % (<50 nmol/l) or 77 % (<75 nmol/l). Of the patients using a vitamin D supplement, 17 % (<50 nmol/l) or 49 % (<75 nmol/l) were still deficient. In non-users of supplemental vitamin D, after adjustment for age and gender, negative associations were found for severe polypharmacy, metformin, sulphonamides and urea derivatives (SUDs), vitamin K antagonists, cardiac glycosides, loop diuretics, potassium-sparing diuretics, ACE inhibitors, and serotonin reuptake inhibitors; for non-selective monoamine reuptake inhibitors (NSMRIs) the association was positive. The most extreme impacts of drug use on adjusted mean 25(OH)D were -19 nmol/l for SUDs and +18 nmol/l for NSMRIs.

CONCLUSION

Drug use should be considered a risk factor for vitamin D deficiency amongst geriatric outpatients.

Obesity and brain inflammation: a focus on multiple sclerosis

The increase in prevalence of obesity in industrialized societies is an indisputable fact. However, the apparent passive role played by adipocytes, in pathophysiological terms, has been gradually substituted by a metabolically active performance, relevant to many biochemical mechanisms that may contribute to a chronic low-grade inflammatory status, which increasingly imposes itself as a key feature of obesity. This chronic inflammatory status will have to be integrated into the complex equation of many diseases in which inflammation plays a crucial role. Multiple sclerosis (MS) is a chronic inflammatory condition typically confined to the central nervous system, and many work has been produced to find possible points of contact between the biology of this immune-mediated disease and obesity. So far, clinical data are not conclusive, but many biochemical features have been recently disclosed. Brain inflammation has been implicated in some of the mechanisms that lead to obesity, which has also been recognized as an important player in inducing some degree of immune dysfunction. In this review, we collected evidence that allows establishing bridges between obesity and MS. After considering epidemiological controversies, we will focus on possible shared mechanisms, as well as on the potential contributions that disease-modifying drugs may have on this apparent relationship of mutual interference.

Calcifediol improves lipid profile in osteopenicatorvastatin-treated postmenopausal women

BACKGROUND

Low vitamin D serum levels have been associated with unfavourable lipid profile and poorer response to atorvastatin. Aims of this study were to test the effects of 25-hydroxyvitamin D3 (calcifediol) compared to parental vitamin D3 (cholecalciferol) supplementation on modifications of plasma 25(OH)D levels and lipid profile.

MATERIALS AND METHODS

Fifty-seven postmenopausal women (aged 59.03 ± 6.73 years) who were at low risk of fracture and with basal plasma 25(OH)D < 30 ng/mL were included if they were on atorvastatin treatment prescribed as appropriate. Recruited women were randomized to receive oral calcifediol or cholecalciferol, both at a dose of 140 μg according to a weekly regimen.

RESULTS

At baseline, 25(OH)D was negatively associated with BMI (r = -0.37; P = 0.004), total cholesterol (r = -0.31; P = 0.01) and LDL-C (r = -0.32; P = 0.02). After 24 weeks, 25(OH)D increased significantly in both groups (P < 0.001), although higher levels were obtained with calcifediol as compared with cholecalciferol (P < 0.001). Only in the calcifediol group, a significant reduction of LDL-C (P = 0.01) and an increase of HDL-C (P = 0.02) were obtained, even after adjustment for age, and baseline BMI, 25(OH)D and lipid levels (P < 0.05). The percentage changes in 25(OH)D levels were associated with the variations of LDL-C (r = -0.44; P = 0.01) and HDL-C levels (r = 0.30; P = 0.10).

CONCLUSION

Calcifediol administration in osteopenic and dyslipidemic postmenopausal women with low 25(OH)D improves lipid profile when added to an ongoing atorvastatin treatment.

Vascular comorbidities in the onset and progression of multiple sclerosis

Vascular comorbidities are common in the general population and are associated with adverse health outcomes. In people with multiple sclerosis (MS), an increasing amount of evidence suggests that vascular comorbidities are also common, but an association with MS risk and disability has not been conclusively established. This review aims to critically examine published data on the relationship between vascular comorbidities (including vascular risk factors) and MS. The evidence suggests an increased risk of MS in people with a high BMI during childhood or adolescence but not adulthood. People with established MS appear to have a slightly increased risk of cardiovascular disease and a greater proportion of people with MS die from cardiovascular disease, which has important implications for clinicians trying to identify risk factors for cardiovascular disease and reviewing treatment options. In relation to whether vascular comorbidities influence MS clinical disability or other aspects of the disease course, the key finding was that having type-2-diabetes, hypertension, dyslipidaemia or peripheral vascular disease at any point in the disease course may be associated with a greater progression in disability. Additionally, a negative effect of high cholesterol and triglycerides and a positive effect of higher HDL (high density lipoprotein) levels on acute inflammatory activity were observed on magnetic resonance imaging. The results of the published clinical trials of statins as an intervention in MS were however conflicting and care needs to be taken when treating people with MS with statins. Taken together, the literature seems to indicate a potential association of vascular comorbidities with MS risk and disability, but the number of prospective studies was sparse, thus precluding ascription of causality. We therefore recommend that future studies of the frequency and effects of vascular comorbidities on MS risk and disability should be prospective and objective where relevant.

Comparative Effect of Atorvastatin and Rosuvastatin on 25-hydroxy-Vitamin D Levels in Non-diabetic Patients with Dyslipidaemia: A Prospective Randomized Open-label Pilot Study

AIMS

Low 25-hydroxy-vitamin D [25(ΟΗ)D] levels have been associated with increased risk for cardiovascular disease. Conflicting data exist regarding the effect of statins on [25(OH)D] levels. The aim of this study was to compare the effect of atorvastatin and rosuvastatin on 25(OH)D levels in non-diabetic patients with dyslipidaemia.

METHODS

This was a prospective randomized open-label study. Patients were assigned to atorvastatin 20 mg⁄day (n=28, age: 56.1±2.2 years, 22 females) or rosuvastatin 10 mg⁄day (n=24, age: 57.4±1.9 years, 20 females). Total cholesterol (TC), low- (LDL-C) and high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), fasting plasma glucose, insulin, glycosylated haemoglobin A1c (HbA1c) and high sensitivity C-reactive protein (hsCRP) levels were measured, and homeostatic model of assessment insulin resistance (HOMA-IR) was calculated at baseline and 12 weeks post-treatment.

RESULTS

There were no within or between group significant differences in 25(OH)D levels (atorvastatin: 21.7±1.9 ng/ml at baseline and 23.5±2.3 ng/ml at week 12; rosuvastatin: 25.3±1.8 and 27.0±2.4 ng/ml, respectively; p=0.172 and p=0.306 for between groups, respectively). Both statins significantly reduced TC, TG and LDL-C levels, with a greater LDL-C reduction being observed by rosuvastatin.

CONCLUSION

Atorvastatin and rosuvastatin did not significantly affect 25(OH)D levels in this study.

Dietary modulators of statin efficacy in cardiovascular disease and cognition

Cardiovascular disease remains the leading cause of morbidity and mortality in the United States and other developed countries, and is fast growing in developing countries, particularly as life expectancy in all parts of the world increases. Current recommendations for the prevention of cardiovascular disease issued jointly from the American Academy of Cardiology and American Heart Association emphasize that lifestyle modification should be incorporated into any treatment plan, including those on statin drugs. However, there is a dearth of data on the interaction between diet and statins with respect to additive, complementary or antagonistic effects. This review collates the available data on the interaction of statins and dietary patterns, cognition, genetics and individual nutrients, including vitamin D, niacin, omega-3 fatty acids, fiber, phytochemicals (polyphenols and stanols) and alcohol. Of note, although the available data is summarized, the scope is limited, conflicting and disparate. In some cases it is likely there is unrecognized synergism. Virtually no data are available describing the interactions of statins with dietary components or dietary pattern in subgroups of the population, particularly those who may benefit most were positive effects identified. Hence, it is virtually impossible to draw any firm conclusions at this time. Nevertheless, this area is important because were the effects of statins and diet additive or synergistic harnessing the effect could potentially lead to the use of a lower intensity statin or dose.

Vitamin D status and hypercholesterolemia in Spanish general population

Low serum 25-hydroxyvitamin D [25(OH)D] levels have been associated with increased prevalence of cardiovascular diseases. A possible relation between lipids and 25(OH)D might explain this association. This investigation aimed to determine the association between vitamin D and cholesterol, as well as the influence of statins on this association. This was a cross-sectional population-based study with 177 subjects aged 18-84 years. We collected demographics and data on sun exposure, sun protection habits, current medication including lipid-lowering drugs, and estimated vitamin D intake. Serum measurements included levels of 25(OH)D, parathyroid hormone (PTH), calcium, phosphorus, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, and fasting glucose. The mean 25(OH)D level was 24 ± 9 ng/ml. Young age (P = 0.04) and spending more than 1 h outdoors (P = 0.04) were independently associated with higher 25(OH)D levels. The 25(OH)D concentrations correlated negatively with total cholesterol (P = 0.01) and LDL cholesterol (P = 0.04) levels. The adjusted OR for total cholesterol > 200 mg/ml was 2.8 (range, 1.1-7.5). Receiving statins was associated with higher 25(OH)D levels (P = 0.04). In conclusion, this study supports an association between 25(OH)D levels and cholesterol. Further studies are required to explain this association.

The role of vitamin D in metabolic disturbances in polycystic ovary syndrome: a systematic review

CONTEXT

Metabolic disturbances, in particular, insulin resistance (IR) and dyslipidemia, are common in women suffering from polycystic ovary syndrome (PCOS). Evidence is accumulating that vitamin D status may contribute to the development of metabolic disturbances in PCOS.

OBJECTIVE

The aim of this study was to carry out a systematic review addressing the association between vitamin D status, vitamin D receptor polymorphisms, and/or polymorphisms related to vitamin D metabolism and metabolic disturbances in women with PCOS.

DESIGN AND METHODS

A systematic search of electronic databases was carried out up to January 2013 for observational studies and clinical trials in women suffering from PCOS with outcome measures that were related to vitamin D status. We conducted univariate and multivariate regression analyses of the weighted means to gain insights into the association between vitamin D, BMI, and IR based on existing literature.

RESULTS

We found 29 eligible trials with inconsistency in their results. One well-designed randomized controlled trial has been carried out until now. Univariate regression analyses of the weighted means revealed vitamin D to be a significant and independent predictor of IR in both PCOS and control women. The significance disappeared after adjustment for BMI in PCOS women.

CONCLUSIONS

Current evidence suggests an inverse association between vitamin D status and metabolic disturbances in PCOS. Owing to the heterogeneity of the studies, it is hard to draw a definite conclusion. The causal relationship between vitamin D status and metabolic disturbances in PCOS remains to be determined in well-designed placebo-controlled randomized clinical trials.

The effect of atorvastatin and simvastatin on vitamin D, oxidative stress and inflammatory marker concentrations in patients with type 2 diabetes: a crossover study

The pleiotropic effect of statins may be mediated in part through raising 25 hydroxy vitamin D (25OHD) concentrations. It has also been shown that an increase in oxidative stress and inflammatory markers are a feature of the patients with type 2 diabetes (T2DM). A cross-over study of 26 patients with T2DM taking either simvastatin 40 mg or atorvastatin 10 mg was undertaken. After 3 months on one statin, lipids, C-reactive protein (hsCRP), 25OHD and malondialdehyde (MDA) were measured repeatedly. The same procedure was then followed taking the other statin. Despite similar lipid-lowering, the mean 25OHD was higher on atorvastatin compared with simvastatin and the mean MDA and hsCRP levels lower, irrespective of which statin the patients were taking before crossover. The changes in 25OHD predicted changes in CRP and MDA levels. Thus, compared with simvastatin, atorvastatin shows apparently beneficial pleiotropic effects with respect to 25OHD concentrations as well as markers of oxidative stress and inflammation in patients with T2DM.

Vitamin D status and dietary intake in a Swedish COPD population

INTRODUCTION

Emerging evidence indicates that patients with chronic obstructive pulmonary disease (COPD) have a poorer vitamin D status than the general population, possibly affecting several comorbidities. In northern latitudes, these problems could be even more accentuated in wintertime because of the low ultraviolet B radiation.

OBJECTIVES

To examine the dietary intake of vitamin D and the levels of 25-hydroxyvitamin D (25-OH-D) in a COPD population compared with a reference group in Swedish settings.

METHODS

Ninety-eight COPD patients (forced expiratory volume in 1 s/vital capacity ratio < 0.65) recruited from the outpatient clinics at the university hospitals in Gothenburg and Uppsala, Sweden were included in this cross-sectional study. The reference group (149 individuals) was randomly selected from the Swedish National Registry. The serum concentrations of 25-OH-D, intact parathyroid hormone, creatinine and calcium were measured. A trained dietitian conducted a dietary history interview to evaluate food intake of vitamin D, prescribed drugs and supplements containing vitamin D.

RESULTS AND CONCLUSIONS

The mean serum concentration of 25-OH-D was significantly higher in the reference group (57.6 ± 23 nmol/L) compared with the COPD group (51.5 ± 22 nmol/L) (P = 0.039). The dietary intake was predominantly below the recommendations in both groups. Mean total daily intake of vitamin D and mean daily supplementation of vitamin D was significantly higher in the COPD group (P = 0.012 and P = 0.030, respectively). Low intake of vitamin D and low serum levels of 25-OH-D are common in both COPD patients and an elderly Swedish population. Monitoring vitamin D status and possibly routinely treating COPD patients with vitamin D and calcium should be considered to minimise the risk of severe vitamin D deficiency among COPD patients.

Changes in circulating 25-hydroxyvitamin D according to vitamin D binding protein genotypes after vitamin D₃ or D₂supplementation

Background

It is not known whether genetic variation in the vitamin D binding protein (DBP) influences 25-hydroxyvitamin D levels [25(OH)D] after vitamin D supplementation. We aimed to investigate the changes of total 25(OH)D, 25(OH)D₃ and 25(OH)D₂ in a Thai cohort, according to type of vitamin D supplement (vitamin D₃ or D₂) and DBP genotype, after receiving vitamin D₃ or D₂ for 3 months.

Methods

Thirty-nine healthy subjects completed the study. All subjects received 400 IU of either vitamin D₃ or D₂, plus a calcium supplement, every day for 3 months. Total serum 25(OH)D, 25(OH)D₃ and 25(OH)D₂ were measured by LC-MS/MS. Individual genotyping of rs4588 in the DBP gene was performed using real-time PCR.

Results

Vitamin D₃ supplementation of 400 IU/d increased 25(OH)D₃ significantly (+16.2 ± 4.2 nmol/L, p <0.001). Vitamin D₂ (400 IU/d) caused increased 25(OH)D₂ levels (+22.0 ± 2.11 nmol/L, p <0.001), together with a decrease of 25(OH)D₃ (−14.2 ± 2.0 nmol/L, p <0.001). At 3 month, subjects in vitamin D₃ group tended to have higher total 25(OH)D levels than those in vitamin D₂ (67.8 ± 3.9 vs. 61.0 ± 3.0 nmol/L; p = 0.08). Subjects were then classified into two subgroups: homozygous for the DBP rs4588 C allele (CC), and the rest (CA or AA). With D₃ supplementation, subjects with CA or AA alleles had significantly less increase in 25(OH)D₃ and total 25(OH)D when compared with those with the CC allele. However, no difference was found when the supplement was vitamin D₂.

Conclusion

Genetic variation in DBP (rs4588 SNP) influences responsiveness to vitamin D₃ but not vitamin D₂.

Atorvastatin reduces malondialdehyde concentrations in patients with polycystic ovary syndrome

BACKGROUND

It has been shown that there is an increase in oxidative stress in polycystic ovary syndrome (PCOS). Statins are considered to have a pleiotropic effect other than their lipid-lowering effect. These effects may be mediated in part by reducing oxidative stress.

METHODS

This randomized, double-blind, placebo-controlled study was conducted to assess the effect of atorvastatin on serum malondialdehyde (MDA) concentrations as a marker of oxidative stress in patients with PCOS. Forty medication-naïve patients with PCOS were randomized to either atorvastatin 20 mg daily or placebo for 3 months. A 3-month extension study for both groups of patients was undertaken with metformin 1500 mg daily after completing initial 3 months of atorvastatin or placebo.

RESULTS

There was a significant decrease of MDA concentrations with atorvastatin [mean (sem)] [0.29 (0.04) vs. 0.25 (0.02) μmol/liter; P < 0.01] compared with placebo [0.28 (0.02) vs. 0.29 (0.12) μmol/liter; P = 0.52]. Three months treatment with metformin resulted in further reduction of MDA levels with atorvastatin compared with baseline [0.25 (0.02) baseline vs. 0.23 (0.03) μmol/liter for atorvastatin treated; P = 0.02]. There was also a significant correlation between the reduction in MDA with a reduction in high-sensitivity C-reactive protein (r = 0.71, P < 0.01), an increase in 25-hydroxyvitamin D (25OHD; r = -0.68, P = 0.02), and a reduction in testosterone levels (r = 0.63, P = 0.01). Multiple linear regression analysis revealed Δ25OHD, ΔC-reactive protein, and Δtestosterone were independent predictors of changes in MDA after atorvastatin treatment. No correlation was observed between the reductions in serum MDA concentrations with changes in the lipid parameters.

CONCLUSIONS

Twelve weeks of atorvastatin led to a significant reduction in oxidative stress as determined by MDA concentrations among patients with polycystic ovary syndrome that was independently predicted by changes in testosterone, 25OHD, and high-sensitivity C-reactive protein.

Vitamin D in the aetiology and management of polycystic ovary syndrome

Vitamin D deficiency is common in women with polycystic ovary syndrome (PCOS), with the 67-85% of women with PCOS having serum concentrations of 25-hydroxy vitamin D (25OHD) <20 ng/ml. Vitamin D deficiency may exacerbate symptoms of PCOS, with observational studies showing lower 25OHD levels were associated with insulin resistance, ovulatory and menstrual irregularities, lower pregnancy success, hirsutism, hyperandrogenism, obesity and elevated cardiovascular disease risk factors. There is some, but limited, evidence for beneficial effects of vitamin D supplementation on menstrual dysfunction and insulin resistance in women with PCOS. Vitamin D deficiency may play a role in exacerbating PCOS, and there may be a place for vitamin D supplementation in the management of this syndrome, but current evidence is limited and additional randomized controlled trials are required to confirm the potential benefits of vitamin D supplementation in this population.

Vitamin D and fertility: a systematic review

BACKGROUND

Vitamin D has been well-known for its function in maintaining calcium and phosphorus homeostasis and promoting bone mineralization. There is some evidence that in addition to sex steroid hormones, the classic regulators of human reproduction, vitamin D also modulates reproductive processes in women and men.

AIM

The aim of this review was to assess the studies that evaluated the relationship between vitamin D and fertility in women and men as well as in animals.

METHODS

We performed a systematic literature search in Pubmed for relevant English language publications published until October 2011.

RESULTS AND DISCUSSION

The vitamin D receptor (VDR) and vitamin D metabolizing enzymes are found in reproductive tissues of women and men. Vdr knockout mice have significant gonadal insufficiency, decreased sperm count and motility, and histological abnormalities of testis, ovary and uterus. Moreover, we present evidence that vitamin D is involved in female reproduction including IVF outcome (clinical pregnancy rates) and polycystic ovary syndrome (PCOS). In PCOS women, low 25-hydroxyvitamin D (25(OH)D) levels are associated with obesity, metabolic, and endocrine disturbances and vitamin D supplementation might improve menstrual frequency and metabolic disturbances in those women. Moreover, vitamin D might influence steroidogenesis of sex hormones (estradiol and progesterone) in healthy women and high 25(OH)D levels might be associated with endometriosis. In men, vitamin D is positively associated with semen quality and androgen status. Moreover, vitamin D treatment might increase testosterone levels. Testiculopathic men show low CYP21R expression, low 25(OH)D levels, and osteoporosis despite normal testosterone levels.

The impact of medication on vitamin D status in older individuals

OBJECTIVE

Vitamin D deficiency and polypharmacy are common in the elderly. However, knowledge on the associations between the use of specific medicines and serum 25-hydroxyvitamin D (25(OH)D) is limited. The aim of this study was to (better) define the associations between the use of specific medicines and serum 25(OH)D.

METHODS

Two different cohorts (1995/1996 and 2002/2003) from the Longitudinal Aging Study Amsterdam (LASA) were used for cross-sectional analyses. LASA is based on an age and sex-stratified random sample of the Dutch older population. Study participants were aged 65-88 years in the first cohort (n = 1301) and 55-65 years in the second cohort (n = 736). Serum 25(OH)D of users of several groups of medicines were compared with levels of non-users using multiple linear regression analysis.

RESULTS

Of all participants, 75.4% (first cohort) and 61.1% (second cohort) were using at least one medicine. In both cohorts, the number of medicines was associated with lower serum 25(OH)D. In the first cohort, after adjustment for confounding, users of any kind of medicine, loop diuretics and inhaled corticosteroids (only men) had respectively 4.4 nmol/l (P<0.01), 4.7 nmol/l (P = 0.04) and 7.3 nmol/l (P = 0.02) lower serum 25(OH)D than non-users. In the second cohort, the use of oral antidiabetics, calcium-channel blockers and angiotensin-converting enzyme inhibitors was associated with respectively 7.4 nmol/l (P = 0.04), 7.7 nmol/l (P = 0.01) and 7.6 nmol/l (P<0.01) lower serum 25(OH)D.

CONCLUSIONS

These data show that users of several medicines have lower serum 25(OH)D than non-users. Vitamin D supplementation may be considered in patients with chronic use of medicines.

Effects of simvastatin and metformin on polycystic ovary syndrome after six months of treatment

CONTEXT

A randomized trial on women with polycystic ovary syndrome (PCOS) compared simvastatin, metformin, and a combination of these drugs.

OBJECTIVE

The aim of the study was to evaluate long-term effects of simvastatin and metformin on PCOS.

DESIGN

Women with PCOS (n = 139) were randomized to simvastatin (S), metformin (M), or simvastatin plus metformin (SM) groups. Evaluations were performed at baseline and at 3 and 6 months.

SETTING

The study was conducted at a university medical center.

PRIMARY OUTCOME

We measured the change of serum total testosterone.

RESULTS

Ninety-seven subjects completed the study. Total testosterone decreased significantly and comparably in all groups: by 25.6, 25.6, and 20.1% in the S, M, and SM groups, respectively. Both simvastatin and metformin improved menstrual cyclicity and decreased hirsutism, acne, ovarian volume, body mass index, C-reactive protein, and soluble vascular cell adhesion molecule-1. Dehydroepiandrosterone sulfate declined significantly only in the S group. Total cholesterol and low-density lipoprotein cholesterol significantly declined only in the S and SM groups. Ongoing reduction of ovarian volume, decreased hirsutism, acne and testosterone were observed between 0 and 3 months as well as between 3 and 6 months. Improvement of lipid profile, C-reactive protein, and soluble vascular cell adhesion molecule-1 occurred only during the first 3 months of treatment, with little change thereafter. Treatments were well tolerated, and no significant adverse effects were encountered.

CONCLUSIONS

Long-term treatment with simvastatin was superior to metformin. Improvement of ovarian hyperandrogenism continued throughout the duration of the study.

Statins for women with polycystic ovary syndrome not actively trying to conceive

BACKGROUND

Statins, as lipid-lowering agents with pleiotropic actions, are likely not only to improve the dyslipidaemia associated with polycystic ovary syndrome but may also exert other beneficial metabolic and endocrine effects.

OBJECTIVES

To assess the efficacy and safety of statin therapy for women with polycystic ovary syndrome (PCOS) who are not actively trying to conceive.

SEARCH STRATEGY

We searched the following databases (from inception to week 1, July 2011): the Cochrane Menstrual Disorders and Subfertility Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE and CINAHL. We handsearched relevant conference proceedings and references of the identified articles for additional studies. We also contacted experts for further studies in progress.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing a statin versus placebo or statin in combination with another drug versus another drug alone in women with PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors performed data collection and analysis independently.

MAIN RESULTS

Four trials fulfilled the criteria for inclusion. They comprised a total of 244 women with PCOS receiving 12 weeks or 6 weeks of treatment. Two trials (184 women randomised) studied the effects of simvastatin and two trials (60 women randomised) studied the effects of atorvastatin. There was no good evidence that statins improved menstrual regularity, spontaneous ovulation rate, hirsutism or acne, either alone or in combination with the combined oral contraceptive pill (OCP). Nor were there any significant effects on body mass index (BMI). Statins were effective in lowering testosterone levels (nmol/L) (mean difference (MD) -0.90, 95% CI -1.18 to -0.62, P < 0.00001, 3 RCTs, 105 women) when used alone or with the OCP. Statins also improved total cholesterol, low-density lipoprotein (LDL) and triglycerides but had no significant effect on high-density lipoprotein (HDL) levels, high sensitivity (HS) C-reactive protein (HS-CRP), fasting insulin or homeostatic model assessment (HOMA) insulin resistance. No serious adverse events were reported in any of the included studies.

AUTHORS' CONCLUSIONS

Although statins improve lipid profiles and reduce testosterone levels in women with PCOS, there is no evidence that statins improve resumption of menstrual regularity or spontaneous ovulation, nor is there any improvement of hirsutism or acne. There is a need for further research to be performed with large sample sizes and well-designed RCTs to assess clinical outcomes.

Genetic Ancestry, Skin Reflectance and Pigmentation Genotypes in Association with Serum Vitamin D Metabolite Balance

BACKGROUND

Lower serum vitamin D (25(OH)D) among individuals with African ancestry is attributed primarily to skin pigmentation. However, the influence of genetic polymorphisms controlling for skin melanin content has not been investigated. Therefore, we investigated differences in non-summer serum vitamin D metabolites according to self-reported race, genetic ancestry, skin reflectance and key pigmentation genes (SLC45A2 and SLC24A5).

MATERIALS AND METHODS

Healthy individuals reporting at least half African American or half European American heritage were frequency matched to one another on age (+/- 2 years) and sex. 176 autosomal ancestry informative markers were used to estimate genetic ancestry. Melanin index was measured by reflectance spectrometry. Serum vitamin D metabolites (25(OH)D₃, 25(OH)D ₂ and 24,25(OH)₂D₃) were determined by high performance liquid chromatography (HPLC) tandem mass spectrometry. Percent 24,25(OH)₂D₃ was calculated as a percent of the parent metabolite (25(OH)D₃). Stepwise and backward selection regression models were used to identify leading covariates.

RESULTS

Fifty African Americans and 50 European Americans participated in the study. Compared with SLC24A5 111^Thr homozygotes, individuals with the SLC24A5 111^Thr/Ala and 111^Ala/Ala genotypes had respectively lower levels of 25(OH)D₃ (23.0 and 23.8 nmol/L lower, p-dominant=0.007), and percent 24,25(OH)₂D₃ (4.1 and 5.2 percent lower, p-dominant=0.003), controlling for tanning bed use, vitamin D/fish oil supplement intake, race/ethnicity, and genetic ancestry. Results were similar with melanin index adjustment, and were not confounded by glucocorticoid, oral contraceptive, or statin use.

CONCLUSIONS

The SLC24A5 111^Ala allele was associated with lower serum vitamin 25(OH)D₃ and lower percent 24,25(OH)₂D₃, independently from melanin index and West African genetic ancestry.

Opposite effects of pravastatin and atorvastatin on insulin sensitivity in the rat: role of vitamin D metabolites

OBJECTIVE

Recent studies indicate that pravastatin improves whereas other statins impair glucose homeostasis in humans, but the underlying mechanisms are not clear. We examined the effect of pravastatin and atorvastatin on insulin sensitivity in a rat model.

METHODS

Pravastatin (40 mg/kg/day) or atorvastatin (20mg/kg/day) were administered for 3 weeks and insulin sensitivity was assessed by measuring fasting plasma insulin, HOMA-IR, non-esterified fatty acids (NEFA) and glycerol levels, as well as by the hyperinsulinemic euglycemic clamp.

RESULTS

Pravastatin had no effect on fasting insulin and HOMA-IR but significantly reduced plasma NEFA and glycerol levels and increased glucose infusion rate (GIR) during the hyperinsulinemic clamp. Increase in GIR induced by pravastatin was not abolished by NO synthase inhibitor, l-NAME, indicating that this effect did not result from the improvement of endothelial function. Atorvastatin increased fasting insulin, HOM-IR, NEFA and glycerol levels as well as reduced GIR. Statins had no effect on leptin, HMW adiponectin, resistin, visfatin, interleukin-6 and TNF-α. Pravastatin increased plasma concentrations of 25-hydroxy- and 1,25-dyhydroxyvitamin D(3) (25-OH-D(3) and 1,25-(OH)(2)-D(3)), and its effect on insulin sensitivity was mimicked by exogenous 1,25-(OH)(2)-D(3). Atorvastatin reduced plasma 25-OH-D(3) but had no effect on 1,25-(OH)(2)-D(3). Decrease in insulin sensitivity induced by atorvastatin was not corrected by supplementation of vitamin D(3) despite normalization of plasma 25-OH-D(3) level.

CONCLUSIONS

Pravastatin and atorvastatin have opposite effects on insulin sensitivity and vitamin D(3) status. Pravastatin-induced increase in insulin sensitivity is mediated by elevation of 1,25-(OH)(2)-D(3). In contrast, atorvastatin-induced decrease in insulin sensitivity is independent of lowering 25-OH-D(3).