Catechol-O-methyltransferase gene polymorphism is associated with skeletal muscle properties in older women alone and together with physical activity

Abstract

Background: Muscle strength declines on average by one percent annually from midlife on. In postmenopausal women this decrement coincides with a rapid decline in estrogen production. The genetics underlying the effects of estrogen on skeletal muscle remains unclear. In the present study, we examined whether polymorphisms within COMT and ESR1 are associated with muscle properties and assessed their interaction and their combined effects with physical activity. Methodology/Principal Findings: A cross-sectional data analysis was conducted with 436 63-76-year old women from the population based Finnish Twin Study on Aging Bdy anthropometry, muscle cross-sectional area (MCSA) isometric hand grip and knee extension strengths, and leg extension power were measured COMT Vall 58Met and ESR1 Pvull genotypes were determined by the RFLP methods mCSA differed by COMT genotypes (p=0.014) being significantly larger in LL than HL individuals in adjusted (p=0.001) and age and height-adjusted model (p=0.004). When physical activity and age were entered into GEE model, COMT genotype had a significant main effect (p=0.038) on MCSA. Furthermore, sedentary individuals with the HH genotype had lower muscle mass strength and power, but they also appeared to benefit the most from physical activity. No association of ESR1 Pvull polymorphism with any of the muscle outcomes was observed. Conclusions/Significance: The present study suggests that the COMT polymorphism, affecting the activity of the enzyme, is associated with muscle mass. Furthermore, sedentary individuals with potential high enzyme activity were the weakest group, but they may potentially benefit the most from physical activity. This observation elucidates the importance of both environmental and genetic factors in muscle properties. © 2008 Ronkainen et al.