Genetic and environmental influences on skeletal muscle phenotypes as a function of age and sex in large, multigenerational families of African heritage
Journal of applied physiology
; 103(4): 1121-1127, Oct. 2007. tab
Artigo
em Inglês
| MedCarib
| ID: med-17704
Biblioteca responsável:
TT5
Localização: TT5; W1, JO542KB
ABSTRACT
The aim of this study was to estimate the heritability of and environmental contributions to skeletal muscle phenotypes (appendicular lean mass and calf muscle cross-sectional area) in subjects of African descent and to determine whether heritability estimates are impacted by sex or age. Body composition was measured by dual-energy X-ray absorptiometry and computed tomography in 444 men and women aged 18 yr and older (mean 43 yr) from eight large, multigenerational Afro-Caribbean families (family size range 21-112). Using quantitative genetic methods, we estimated heritability and the association of anthropometric, lifestyle, and medical variables with skeletal muscle phenotypes. In the overall group, we estimated the heritability of lean mass and calf muscle cross-sectional area (h(2) = 0.18-0.23, P < 0.01) and contribution of environmental factors to these phenotypes (r(2) = 0.27-0.55, P < 0.05). In our age-specific analysis, the heritability of leg lean mass was lower in older vs. younger individuals (h(2) = 0.05 vs. 0.23, respectively, P = 0.1). Sex was a significant covariate in our models (P < 0.001), although sex-specific differences in heritability varied depending on the lean mass phenotype analyzed. High genetic correlations (rho(G) = 0.69-0.81; P < 0.01) between different lean mass measures suggest these traits share a large proportion of genetic components. Our results demonstrate the heritability of skeletal muscle traits in individuals of African heritage and that heritability may differ as a function of sex and age. As the loss of skeletal muscle mass is related to metabolic abnormalities, disability, and mortality in older individuals, further research is warranted to identify specific genetic loci that contribute to these traits in general and in a sex- and age-specific manner.
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
MedCarib
Assunto principal:
Composição Corporal
/
Peso Corporal
/
Família
/
Fatores Etários
/
População Negra
/
Meio Ambiente
Tipo de estudo:
Estudo prognóstico
Limite:
Adolescente
/
Adulto
/
Idoso
/
Idoso, 80 anos ou mais
/
Feminino
/
Humanos
/
Masculino
País/Região como assunto:
Caribe Inglês
/
Trinidad e Tobago
Idioma:
Inglês
Revista:
Journal of applied physiology
Ano de publicação:
2007
Tipo de documento:
Artigo
Instituição/País de afiliação:
Tobago Health/Trinidad and Tobago
/
University of Maryland School of Medicine/United States of America
/
University of Maryland/United States of America
/
University of Pittsburgh/United States of America