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.