Patterns of menopausal hormone therapy use and hyperkyphosis in older women

Objective: Hyperkyphosis, an exaggerated anterior curvature of the thoracic spine, is associated with poor physical function, falls, fractures, and earlier mortality. Low bone mineral density, bone loss, and vertebral fractures are strong risk factors for hyperkyphosis. Menopausal hormone therapy (HT) reverses bone loss, prevents vertebral fractures, and, therefore, we hypothesize, may reduce the risk for developing hyperkyphosis. Methods: We evaluated the cross-sectional association between Cobb angle of kyphosis from lateral spine radiographs and pattern of self-reported HT use during the prior 15-year period in 1,063 women from the Study of Osteoporotic Fractures. Results: Participants had a mean age of 83.7±3.3 years and a mean Cobb angle of 51.3±14.6°. Forty-six per cent of women were characterized as never-users of HT, 24% as remote past users, 17% as intermittent users, and 12% as continuous users. In minimally adjusted models, the mean Cobb angle was 4.0° less in continuous HT users compared with never-users (P=0.01); however, in fully adjusted models, this association was attenuated to 2.8° (P=0.06). Remote past HT users had 3.0° less kyphosis compared with never-users in minimally adjusted models (P=0.01), attenuated to 2.8° less in fully adjusted models (P=0.02). Intermittent users did not differ from never-users in degree of kyphosis. Conclusions: Women reporting continuous or remote past HT use had less pronounced kyphosis than never-users by their mid-eighties, suggesting a possible role for HT in the prevention of age-related hyperkyphosis.