Associations of statin use with motor performance and myalgia may be modified by 25-hydroxyvitamin D: findings from a British birth cohort.

The objective was to examine whether: (1) statin use was associated with muscle related outcomes at age 60-64, (2) these associations were modified by 25-hydroxyvitamin D (25(OH)D) status and explained by inflammation, body-size or lifestyle in a British birth cohort. Markers of myalgia (intrusive body pain) and myopathy (self-reported and performance-based measures) were examined in 734 men and 822 women (MRC National Survey of Health and Development). Statin use was associated with intrusive body pain, difficulty climbing stairs and slower chair rise speed. Some associations were modified by 25(OH)D e.g. the association with intrusive body pain was evident in the insufficient (13-20 ng/l) and deficient (<13 ng/l) 25(OH)D status groups (OR = 2.6,95% CI 1.7-1.1; OR = 1.8,95% CI 1.2-2.8, respectively) but not in those with status >20 ng/l (OR = 0.8,95% CI 0.5-1.4) (p = 0.003 for interaction). Associations were maintained in fully adjusted models of intrusive body pain and difficulty climbing stairs, but for chair rise speed they were fully accounted for by inflammation, body-size and lifestyle. In a nationally representative British population in early old age, statin use was associated with lower limb muscle-related outcomes, and some were only apparent in those with 25(OH)D status below 20 ng/l. Given 25(OH)D is modifiable in clinical practice, future studies should consider the links between 25(OH)D status and muscle related outcomes.