title: 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.
  
  
  RESULTS
  A cross-sectional data analysis was conducted with 434 63-76-year-old women from the population-based Finnish Twin Study on Aging. Body anthropometry, muscle cross-sectional area (mCSA), isometric hand grip and knee extension strengths, and leg extension power were measured. COMT Val158Met and ESR1 PvuII genotypes were determined by the RFLP method. mCSA differed by COMT genotypes (p = 0.014) being significantly larger in LL than HL individuals in unadjusted (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 PvuII polymorphism with any of the muscle outcomes was observed.
  
  
  CONCLUSIONS
  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.
authors: Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland. paula.ronkainen@sport.jyu.fi
authors: Paula H A
authors: PH
authors: Ronkainen
authors: Eija
authors: E
authors: Pöllänen
authors: Timo
authors: T
authors: Törmäkangas
authors: Kristina
authors: K
authors: Tiainen
authors: Markku
authors: M
authors: Koskenvuo
authors: Jaakko
authors: J
authors: Kaprio
authors: Taina
authors: T
authors: Rantanen
authors: Sarianna
authors: S
authors: Sipilä
authors: Vuokko
authors: V
authors: Kovanen
mesh_terms: D000368:Aged; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D015444:Exercise; D005260:Female; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000201:enzymology / Q000502:physiology*; D011110:Polymorphism, Genetic
chemical_list: D002394:Catechol O-Methyltransferase