Low Plasma Vitamin D Levels and Muscle-Related Adverse Effects in Statin Users

Background: Treatment with HMG-CoA reductase inhibitors (Statins) is often complicated by muscle related adverse effects (MAEs). Studies of the association between low plasma vitamin D levels and MAEs have yielded conflicting results. Objectives: To determine if low plasma vitamin D level is a risk factor for MAEs in statin users. Methods: Plasma levels of 25(OH) vitamin D were measured as part of the routine evaluation of unselected statin-treated patients attending the coronary and lipid, clinics at our hospital curing the period 2007-2010. Medical data on muscle complaints and statin use were retrieved from the medical files. Creatine kinase (CK) levels were derived from the hospital laboratory database. Results: The sample included 272 patients (141 men) aged 33-89 years. Mean vitamin D level was 48.04 nmol/L. Levels were higher in men (51.0 +/- 20.5 vs. 44.7 +/- 18.9 nmol/L, P = 0.001) and were unaffected by age. MAEs were observed in 106 patients (39%): myalgia in 95 (35%) and CK elevation in 20(7%); 9 patients (3%) had both. There was no difference in plasma vitamin D levels between patients with and without myalgia (46.3 +/- 17.7 vs. 48.9 +/- 21.0 nmol/L, P = 0.31), with and without CK elevation (50.2 +/- 14.6 vs. 47.8 +/- 20.3 nmol/L, P = 0.60), or with or without any MAE (50.4 +/- 15.0 vs. 47.8 +/- 10.2 nmol/L, P = 0.27). These findings were consistent when analyzed by-patient gender and presence/absence of coronary artery disease; and when using:a lower vitamin D cutoff (<25 nmol/L). Conclusions: There is apparently no relationship between plasma vitamin D level and risk of MAEs in statin users.