Age- and Gender-related Differences of Muscle Mass in Korean

Kim, Hyunsoo

Abstract

BACKGROUND
The purpose of this study was to examine the impact of age and gender on muscle mass (MM) and its distribution in a large and heterogeneous sample of Korean population.
METHODS
Subjects were 5,781 healthy Korean adults (2,512 men and 3,269 women) aged 20 to 88 years. The present study used dual X-ray energy absorptiometry to estimate the MM of arms, legs, trunk and whole body.
RESULTS
Men had significantly (P < 0.001) greater MM in comparison to women in both absolute (48.2 vs. 33.4 kg) and relative (70.2 vs. 58.9%) terms to body mass. The gender differences were greater in the upper body (9.1 kg) than in the lower body (5.6 kg) (P < 0.001). There was a curvilinear relationship between age and MM for both men and women. The slope of the regression line between age and MM was greater in men than in women throughout all parts of the body. The changes in MM with advancing age were different for each part of the body. The decrease in leg MM, beginning after the second (women: fourth) decade, was the greatest reduction out of all parts of the body with advancing age.
CONCLUSION
Aging is associated with a decrease in MM that is explained by a decrease in lower extremity muscle occurring after the sixth decade for both men and women. This study may be useful when comparing with populations of different ethnic backgrounds and studying ill subjects.