Muscle strength and serum testosterone, cortisol and SHBG concentrations in middle-aged and elderly men and women.

Forty healthy males (M) and females (F) divided into two different age groups i.e. M50 years (range 44-57; n = 9), F50 years (range 43-54; n = 9), M70 years (range 64-73; n = 11) and F70 years (range 63-73; n = 11) volunteered as subjects for examination of muscle cross-sectional area (CSA) and maximal voluntary isometric force production characteristics of the leg extensor muscles and serum androgen and sex hormone binding globulin (SHBG) concentrations. The CSA in the male groups was greatly larger (P < 0.01) than in the female groups and both elderly groups demonstrated slightly (n.s.) smaller values in the CSA than the two middle-aged groups. Maximal force of 2854 +/- 452 N in M50 was greater (P < 0.05) than that of 2627 +/- 752 N recorded for F50 as well as the force of 2787 +/- 843 in M70 was greater (P < 0.001) than that of 1849 +/- 295 recorded for F70. The force between F50 and F70 differed significantly (P < 0.05) from each other. The maximal rate of force production in M50 was greater (P < 0.01) than in F50 as well as in M70 greater (P < 0.01) than in F70. Both middle-aged groups demonstrated greater (P < 0.05) values than the respective elderly groups of the same sex. The individual values in the CSA correlated with the values in maximal force both in the middle-aged subjects (r = 0.66; P < 0.01) and in the elderly subjects (r = 0.69; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)