ACE Genotype and the Muscle Hypertrophic and Strength Responses to Strength Training

Abstract

Purpose-Previous studies have linked an insertion/deletion polymorphism in the angiotensinconverting enzyme (ACE) gene with variability in muscle strength responses to strength training (ST), though conclusions have been inconsistent across investigations. Moreover, most previous studies have not investigated the influence of sex on the association of ACE I/D genotype with muscle phenotypes. The purpose of this study was to investigate the association of ACE genotype with muscle phenotypes before and after ST in older men and women.Methods-Eighty-six inactive men and 139 inactive women, ages 50-85 yr (mean: 62 yr), were studied before and after 10 wk of unilateral knee extensor ST. The one-repetition maximum (1RM) test was used to assess knee extensor muscle strength, and computed tomography was used to measure quadriceps muscle volume (MV). Differences were compared among ACE genotype groups (II vs ID vs DD).Results-Across the entire cohort at baseline, ACE genotype was significantly associated with total lean mass and body weight, with higher values in DD genotype carriers (both P < 0.05). At baseline, DD genotype carriers exhibited significantly greater MV compared with II genotype carriers for both the trained leg (men: 1828 ± 44 vs 1629 ± 70; women: 1299 ± 34 vs 1233 ± 49; P = 0.02) and untrained leg (men: 1801 ± 46 vs 1559 ± 72; women: 1268 ± 36 vs 1189 ± 51; P = 0.01), with no significant genotype × sex interaction. No ACE genotype associations were observed for the 1RM or MV adaptations to ST in either men or women.Conclusions-In the present study, ACE genotype was associated with baseline differences in muscle volume, but it was not associated with the muscle hypertrophic response to ST. Keywords ANGIOTENSIN-CONVERTING ENZYME; GENETICS; MUSCLE MASS; MUSCLE SIZE; SKELETAL MUSCLEMuscle strength and mass are heritable phenotypes, with a heritability range of 14-80% for strength (1,21,28,30) and 20-85% for muscle mass (1,14,24,28). Although the heritability of the adaptation of these muscle phenotypes to strength training (ST) has not been well studied, the adaptive response also appears to have a genetic component (26,27 The purpose of the present study was to investigate the association of ACE genotype with muscle phenotypes before and after ST in older men and women. Though the literature is inconclusive, the biological rationale suggests an advantage for the D allele with regard to muscle phenotypes; thus, we hypothesized that the D allele would be associated with higher values for muscle phenotypes before ST, and greater increases in muscle phenotypes in response to ST. As most studies have investigated only men, we investigated men and women to determine possible sex differences. METHODS SubjectsParticipants in the study consisted of 243 inactive, healthy volunteers between the ages of 50 and 85 yr. For this investigation, "inactive" was operationally defined as a person who performs less than 20 min of vigorous activity per week. Subjects were required to be nonsmokers with no significant car...

Genetic aspects of skeletal muscle strength and mass with relevance to sarcopenia

“…64,67,68,70 Most have reported no association with muscle mass and it appears unlikely that ACE genotype contributes significantly to muscle mass phenotypes.…”

Genes and the ageing muscle: a review on genetic association studies

“…Published findings are also controversial in older people, starting with the possible association between this polymorphism and muscle mass. Some studies reported a positive association between the D allele and the following phenotypes: muscle mass in healthy inactive old men and women (Charbonneau et al 2008), lean mass (as well as handgrip force) in advanced cancer patients (Vigano et al 2009) or appendicular fat free fat (FFM) in old women (Lima et al 2011). In contrast, McCauley et al found no association with whole body and thigh lean mass in old Caucasians (McCauley et al 2010).…”

“…Charbonneau et al (2008) found no association between the ACE I/D polymorphism and the muscle volume adaptation to resistance training (RT). In contrast, in a study with obese old people, Giaccaglia et al (2008) found greater gains in knee extensor strength in DD homozygotes compared with II homozygotes after 18 months of walking and light RT.…”

Angiotensin-converting enzyme (ACE) genotypes and disability in hospitalized older patients

“…In fact, the D allele has been associated with increased muscle strength and power, whereas the I allele has been associated with improved muscular endurance (Gayagay et al 1998;Myerson et al 1999;Williams et al 2000;Charbonneau et al 2008) and cardio-respiratory performances (Guazzi et al 1999a, b;Payne and Montgomery, 2003;Tsianos et al 2004;Thompson et al 2007). However, data indicating an association between the ACE I/D polymorphism and functional decline or physical performance in older adults are still under debate (Frederiksen et al 2003a, b;Kritchevsky et al 2005;Giaccaglia et al 2008;Yoshihara et al 2009).…”