Timing of Adolescent Somatic Maturity and Midlife Muscle Function: A 34-yr Follow-Up

Midlife muscle function is associated with disability and premature mortality later in life. Biological maturity is associated with muscle function during growth; however, it is unknown whether biological maturity during adolescence is associated with muscle mass and function in middle-aged healthy men. The purpose of this study is to evaluate if late maturation during adolescence is associated with better muscle function in middle-aged men. One hundred and thirty-three middle-aged men 45 to 49 yr were included. During adolescence, height was measured at annual intervals, and age at peak height velocity was derived from the individual growth curves and was used to classify participants into early-, average-, and late-maturing groups. Outcome measurements and tests included lean body mass (dual-energy x-ray absorptiometry), muscle-bone areas, isometric strength, and muscle power. Stature, body mass, cardiorespiratory fitness (V O2peak), and physical activity level were included as confounding characteristics. Contrasting maturity groups did not differ in the confounding characteristics (size, mass, aerobic power, and physical activity). Furthermore, no differences were observed for lean mass and muscle-bone areas. Late-maturing adults had greater strength and power, and average differences were between 0.7 and 0.9 SD units (P < 0.05). Late maturation during adolescence is associated with better muscle function at middle age.