DNA methylation is associated with muscle loss in community-dwelling older men -the Yakumo study- : a preliminary experimental study.

Frailty is a state of reduced muscle strength and activity in older people. DNA methylation is associated with osteoporosis and muscle loss in murine and other animal studies, but there are no epidemiological studies in humans. This study aimed to assess the association of osteoporosis and muscle loss with DNA methylation in community-dwelling older people. This cross-sectional study was performed in a rural part of Japan. We analyzed 204 subjects (98 men and 106 women). In univariate analysis, the two groups were compared according to the presence or absence of osteoporosis and of muscle loss. Logistic regression analysis was performed to determine predictors of frailty in the muscle loss group. We used age, sex, body mass index, smoking history, drinking history, serum albumin and C-reactive protein levels, diabetes, hypertension, hyperlipidemia, heart disease history, and LINE-1 DNA methylation as the factors. Probability values < 0.05 were considered to be statistically significant. The levels of LINE-1 DNA methylation in leukocytes were associated with muscle loss in men over the age of 60. LINE-1 DNA methylation levels were not associated with bone mineral density in either the men or women over the age of 60. LINE-1 DNA methylation levels in leukocytes correlated significantly with the risk of frailty in men over the age of 60. Promoting an understanding of DNA methylation may lead to a better understanding of the pathophysiology of muscle loss.