Abstract
OBJECTIVES To determine whether women with sarcopenia and low bone mineral density (BMD) are at greater risk of clinical fractures than those with sarcopenia or low BMD alone. DESIGN Women's Health Initiative (WHI) Observational and Clinical trials. SETTING Three U.S. clinical centers (Pittsburgh, PA; Birmingham, AL; Phoenix/Tucson, AZ). PARTICIPANTS Women (mean age 63.3 ± 0.07) with BMD measurements (N = 10,937). MEASUREMENTS Sarcopenia was defined as appendicular lean mass values corrected for height and fat mass. Low BMD was defined as a femoral neck T-score less than -1.0 based on the Third National Health and Nutrition Examination Survey reference database for white women. Cox proportional hazards analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). We followed women for incident fractures over a median of 15.9 years. RESULTS Participants were classified into mutually exclusive groups based on BMD and sarcopenia status: normal BMD and no sarcopenia (n = 3,857, 35%), sarcopenia alone (n = 774, 7%), low BMD alone (n = 4,907, 45%), and low BMD and sarcopenia (n = 1,399, 13%). Women with low BMD, with (HR = 1.72, 95% CI = 1.44-2.06) or without sarcopenia (HR = 1.58, 95% CI = 1.37-1.83), had greater risk of fracture than women with normal BMD; the difference remained statistically significant after adjustment for important covariates. Women with low BMD, with (HR = 2.78, 95% CI = 1.78-4.30 and without (HR = 2.42, 95% CI = 1.63-3.59) sarcopenia had higher risk of hip fractures. Women with sarcopenia alone had similar HRs to women with normal BMD. CONCLUSION Compared to women with normal BMD.
