Older women and testosterone: the relationship with three-year decline in physical performance and muscle strength

Context: There is growing interest in the role of low testosterone levels on health in women. However, the effects of lower testosterone levels on decline in physical performance or muscle strength in older women have not yet been investigated. Objective: To investigate the associations between low testosterone levels and three year change in muscle strength and physical performance in a population-based sample of older women. Design and setting: The Health, Aging, and Body Composition study, an ongoing prospective cohort study, includes 3075 black and white men and women, aged 70-79 years. Participants: Data were available for 1510 women with baseline levels of total and free testosterone. Physical performance and grip strength were measured at baseline and after three years. Results: Lower levels of total and free testosterone were not associated with baseline physical performance in analyses of covariance, adjusted for socio-demographic, health and lifestyle factors. However, lower levels of total testosterone were associated with a two times greater three-year decline in physical performance score (mean change -0.16 (SE 0.02) in women with total testosterone levels ≤ 20 ng/dl, compared to a mean change of -0.08 (0.03) in women with levels ≥ 34.7 ng/dl (reference), p=0.01). Lower levels of total and free testosterone were associated with lower baseline grip strength and with greater three-year decline in grip strength in women 73 years or older, but not in younger women. Conclusions: These data suggest an association between low testosterone levels and greater decline in physical performance and grip strength in older women.