Association Between Vitamin D and Statin-Related Myopathy: A Meta-analysis

Lipids, lipid-modified drug target genes, and the risk of male infertility: a Mendelian randomization study

Background

Previous observational studies have reported a possible association between circulating lipids and lipid-lowering drugs and male infertility (MIF), as well as the mediating role of circulating vitamin D. Then, due to issues such as bias, reverse causality, and residual confounding, inferring causal relationships from these studies may be challenging. Therefore, this study aims to explore the effects of circulating lipids and lipid-lowering drugs on MIF through Mendelian randomization (MR) analysis and evaluate the mediating role of vitamin D.

Method

Genetic variations related to lipid traits and the lipid-lowering effect of lipid modification targets are extracted from the Global Alliance for Lipid Genetics Genome-Wide Association Study. The summary statistics for MIF are from the FinnGen 9th edition. Using quantitative expression feature loci data from relevant organizations to obtain genetic variations related to gene expression level, further to explore the relationship between these target gene expression levels and MIF risk. Two-step MR analysis is used to explore the mediating role of vitamin D. Multiple sensitivity analysis methods (co-localization analysis, Egger intercept test, Cochrane's Q test, pleiotropy residuals and outliers (MR-PRESSO), and the leave-one-out method) are used to demonstrate the reliability of our results.

Result

In our study, we observed that lipid modification of four lipid-lowering drug targets was associated with MIF risk, the LDLR activator (equivalent to a 1-SD decrease in LDL-C) (OR=1.94, 95% CI 1.14-3.28, FDR=0.040), LPL activator (equivalent to a 1-SD decrease in TG) (OR=1.86, 95% CI 1.25-2.76, FDR=0.022), and CETP inhibitor (equivalent to a 1-SD increase in HDL-C) (OR=1.28, 95% CI 1.07-1.53, FDR=0.035) were associated with a higher risk of MIF. The HMGCR inhibitor (equivalent to a 1-SD decrease in LDL-C) was associated with a lower risk of MIF (OR=0.38, 95% CI 0.17-0.83, FDR=0.39). Lipid-modifying effects of three targets were partially mediated by serum vitamin D levels. Mediation was 0.035 (LDLR activator), 0.012 (LPL activator), and 0.030 (CETP inhibitor), with mediation ratios of 5.34% (LDLR activator), 1.94% (LPL activator), and 12.2% (CETP inhibitor), respectively. In addition, there was no evidence that lipid properties and lipid modification effects of six other lipid-lowering drug targets were associated with MIF risk. Multiple sensitivity analysis methods revealed insignificant evidence of bias arising from pleiotropy or genetic confounding.

Conclusion

This study did not support lipid traits (LDL-C, HDL-C, TG, Apo-A1, and Apo-B) as pathogenic risk factors for MIF. It emphasized that LPL, LDLR, CETP, and HMGCR were promising drug targets for improving male fertility.

Decoding the Intricacies of Statin-Associated Muscle Symptoms

PURPOSE OF REVIEW

Hyperlipidemia is the major cardiovascular morbidity and mortality risk factor. Statins are the first-line treatment for hyperlipidemia. Statin-associated muscle symptoms (SAMS) are the main reason for the discontinuation of statins among patients. The purpose of this review is to guide clinicians to recognize the difference between self-limited and autoimmune statin myopathy in addition to the factors that potentiate them. Finally, treatment strategies will be discussed. This review mostly focuses on new data in the past 3 years.

RECENT FINDINGS

Recent findings suggest that SAMS is a complex and multifactorial condition that involves mitochondrial dysfunction, oxidative stress, and immune-mediated mechanisms. Effective management of SAMS requires a thorough evaluation of the patient's symptoms, risk factors, and medication history, as well as consideration of alternative treatment options. While statins are effective in reducing the risk of cardiovascular events, their use is associated with a range of adverse effects, including SAMS.

Statin Intolerance: a Review and Update

OBJECTIVE

To review evidence of existing literature on the management of statin intolerance.

METHODS

We searched for literature pertaining to statin intolerance and treatments in PubMed. We reviewed articles published between 2005 and 2022.

RESULTS

Statin-associated myalgia is the most common adverse effect of statin therapy and the most common reason for statin discontinuation. Risk factors for statin intolerance include unexplained muscle pain with other lipid-lowering therapy, unexplained cramps, history of elevated creatinine kinase levels, family history of muscle symptoms, and family history of muscle symptoms with lipid therapy. Vitamin D repletion and coenzyme Q supplementation may help alleviate the musculoskeletal effects of statins. Trials of different types of statins and different dosing regimens are recommended to improve tolerability. The use of statins in individuals who perform regular exercise requires closer attention to muscular symptoms and creatinine kinase levels, but it does not preclude the use of statins.

CONCLUSION

Management of the adverse effects of statin therapy and improving statin tolerability is key to achieving optimum cardiovascular benefits. Identifying statin-associated adverse effects and managing appropriately can reduce unnecessary statin discontinuation and subsequently provide longer cardiovascular protection.

Side effects of statins: from pathophysiology and epidemiology to diagnostic and therapeutic implications

Treatment with statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, has proven beneficial preventive effects on cardiovascular events. However, discontinuation due to intolerance and non-adherence remain two of the major gaps in both primary and secondary prevention. This leads many patients with high-risk of atherosclerotic cardiovascular disease (ASCVD) to be inadequately treated or not to achieve target lipid level goals, and as consequence they undergo an increased risk of cardiovascular events. The aim of this review is thus to give an overview of the reasons for discontinuation and on the possible mechanisms behind them. Although statins, as a class, are generally safe, they are associated with an increased risk of diabetes mellitus and hepatic transaminase elevations. Incidence of cataracts or cognitive dysfunction and others presented in the literature (e.g. proteinuria and haematuria) have been never confirmed to have a causal link. Conversely, debated remains the effect on myalgia. Muscle side effects are the most commonly reported, although myalgia is still believed by some to be the result of a nocebo/drucebo effect. Concerning mechanisms behind muscular side effects, no clear conclusions have been reached. Thus, if on one side it is important to identify individuals either at higher risk to develop a side effect, or with confirmed risk factors and conditions of statin intolerance, on the other side alternative strategies should be identified to avoid an increased ASCVD risk.

Statins Neuromuscular Adverse Effects

Statins are drugs widely prescribed in high-risk patients for cerebrovascular or cardiovascular diseases and are, usually, safe and well tolerated. However, these drugs sometimes may cause neuromuscular side effects that represent about two-third of all adverse events. Muscle-related adverse events include cramps, myalgia, weakness, immune-mediated necrotizing myopathy and, more rarely, rhabdomyolysis. Moreover, they may lead to peripheral neuropathy and induce or unmask a preexisting neuromuscular junction dysfunction. A clinical follow up of patients assuming statins could reveal early side effects that may cause neuromuscular damage and suggest how to better modulate their use. In fact, statin dechallenge or cessation, or the alternative use of other lipid-lowering agents, can avoid adverse events. This review summarizes the current knowledge on statin-associated neuromuscular adverse effects, diagnosis, and management. It is conceivable that the incidence of neuromuscular complications will increase because, nowadays, use of statins is even more diffused than in the past. On this purpose, it is expected that pharmacogenomic and environmental studies will help to timely predict neuromuscular complications due to statin exposure, leading to a more personalized therapeutic approach.

Association Between Vitamin D Supplementation and Statin-Associated Muscle Symptoms: A Systematic Review

INTRODUCTION

Although low vitamin D levels are associated with statin-associated muscle symptoms (SAMS), it remains unclear if vitamin D supplementation leads to symptom improvement.

AIM

We performed a systematic review to evaluate the association of vitamin D supplementation with resolution of SAMS.

METHODS

We searched Medline (PubMed), Embase and Cochrane Library till 12 December 2021. Full length articles that reported on the association between vitamin D supplementation in adult patients with SAMS were included.

RESULTS

We identified 8 interventional studies comprising 669 participants. Majority of the participants were of Caucasian ethnicity and the mean age of participants ranged from 59.5 to 64.8 years old. The studies recruited patients with initial mean pre-treatment vitamin D levels ranging from 17.8 to 22.0ng/mL. Follow up duration ranged from 2 to 24 months and mean post-treatment vitamin D levels ranged from 34.3 to 56.0ng/mL. We found that vitamin D supplementation was associated with improved statin tolerance in 509 out of 606 (83.9%) patients across the 7 studies which reported patient numbers after supplementation (95% CI = 0.81-0.87, I2 = 72% n = 7). None of the studies were randomized controlled trials (RCTs) and hence placebo effect of vitamin D could not be ruled out. Nocebo effect of statin was also not assessed by any of the studies.

CONCLUSION

Vitamin D supplementation in patients with mild-moderate vitamin D insufficiency was associated with improvement of SAMS. However, quantitative efficacy analysis was not possible and this observed association is likely confounded by nocebo and placebo effects. RCTs are required to conclusively assess the utility of vitamin D supplementation in improving SAMS.