title: Single and combined influence of ACE and ACTN3 genotypes on muscle phenotypes in octogenarians.
abstract: We studied the single and combined influence of the ACE I/D and the ACTN3 R577X polymorphisms on muscle phenotypes (thigh muscles' cross-sectional area assessed with magnetic resonance imaging) and strength (maximal handgrip, 30-s chair stand test), functional ability during activities of daily living (Barthel index) and bone mineral density (proximal femur) in Caucasian (Spanish) community-dwelling old people [n = 81, 59 women; mean age 82.8 ± 4.8 years (range 71-93 years)]. We found no significantly differences in the aforementioned phenotypes across ACE and ACTN3 genotypes (all P > 0.05), except for handgrip in the ACE I/D recessive model (DD 19.5 ± 6.7 kg, ID 24.0 ± 9.1 kg, II 22.1 ± 7.9; P = 0.047), yet statistical significance disappeared after correction for multiple comparisons. Likewise, the analyses of the combined effects between genotypes did not yield any significant difference (all P > 0.05) between the two 'extreme' genotypes [theoretically 'power or muscularity oriented' [(ACTN3 RR + RX & ACE DD) versus 'non-power' (ACTN3 XX & ACE II + ID)]. The aforementioned analyses were adjusted by sex, age and physical activity levels as covariates. Logistic regression analysis revealed no significant association of single or combined effect of ACE and ACTN3 genotypes or genotype combination group (ACE + ACTN3) with sarcopenia (i.e. being in the lowest 25th sex-specific percentile for a combined score of the muscle and functional phenotypes we measured). Though ACE I/D and ACTN3 R577X polymorphisms are candidates to modulate exercise-related phenotypes in adults, our data suggest that they do not exert a major influence in the muscle phenotypes of old people. More studies with larger sample sizes are needed.
authors: Faculty of Health and Sport Science, Department of Physiotherapy and Nursing, University of Zaragoza, Ronda Misericordia 5, 22001, Huesca, Spain. nuria.garatachea@unizar.es
authors: Nuria
authors: N
authors: Garatachea
authors: Carmen
authors: C
authors: Fiuza-Luces
authors: Gema
authors: G
authors: Torres-Luque
authors: Thomas
authors: T
authors: Yvert
authors: Catalina
authors: C
authors: Santiago
authors: Félix
authors: F
authors: Gómez-Gallego
authors: Jonatan R
authors: JR
authors: Ruiz
authors: Alejandro
authors: A
authors: Lucia
mesh_terms: D000185:Actinin / Q000235:genetics*; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: C118456:ACTN3 protein, human; D000185:Actinin; C488034:ACE protein, human; D007703:Peptidyl-Dipeptidase A