ACTN3 Gene and Susceptibility to Sarcopenia and Osteoporotic Status in Older Korean Adults

BACKGROUND Little information is available about molecular markers for sarcopenia and osteoporosis in Asian populations. OBJECTIVE This study investigated the association of the ACTN3 polymorphism with sarcopenia and osteoporotic status in older Korean adults. METHODS Older Korean 62 men and 270 women (mean age 73.7 ± 6.6 years) participated in this study. Body mass index, percent body fatness, appendicular skeletal muscle mass, and bone mineral density of the lumbar spine, femur, and total body were analyzed with dual-energy X-ray absorptiometry. ACTN3 R/X genotyping was determined using TaqMan probes. RESULTS Determination of odds ratios (ORs) and 95% confidence intervals (CIs) using binary logistic regression analyses showed that XX homozygotes were at a significantly higher risk of sarcopenia (OR = 2.056, 95%  CI = 1.024-4.127, p = 0.043) and osteoporosis (OR = 2.794, 95%  CI = 1.208-5.461, p = 0.016) than RR homozygotes (reference group, OR = 1). The OR of XX homozygotes for having sarcopenia remained significant (OR = 2.237, 95%  CI = 1.044-4.836, p = 0.038) after adjustments for age, gender, body fatness, and serum vitamin D. The OR of XX homozygotes for having osteoporosis was no longer significant (OR = 2.682, 95%  CI = 0.960-7.942, p = 0.075) after adjustments for the covariates. CONCLUSION Our findings suggest that the ACTN3 R577X genotype may influence decline in muscle and bone health phenotypes in older Korean adults.