Risk of Fracture in Women with Sarcopenia, Low Bone Mass, or Both

Abstract

Objective To determine if sarcopenia in the presence of low bone mineral density (BMD) increases the risk of clinical fractures in women compared to women with either sarcopenia or low BMD alone. Design Women’s Health Initiative (WHI) Observational and Clinical trials Setting 3 US Clinical Centers-Pittsburgh, PA, Birmingham, AL, and Phoenix/Tucson, AZ Participants 10,937 women (mean age 63.3 ± 0.07) with BMD measurements Measurements Sarcopenia was defined as appendicular lean mass values correcting for height and fat mass following the Newman et al approach. Low BMD was defined as a femoral neck T-score < −1.0 based on NHANES III reference database for white women. Cox proportional hazards analysis was used to calculate hazard ratios and 95% confidence intervals. We followed women for incident fractures over a median of 15.9 years. Results Participants were classified into mutually exclusive groups based on their BMD and sarcopenia status: normal BMD and no sarcopenia (n=3,857, 35%),; sarcopenia alone (n=774, 7%),; low BMD alone (n=4907, 45%),; and low BMD and sarcopenia (n=1399, 13%). Women with low BMD, with or without sarcopenia, respectively, had greater risk of fracture than did women with normal BMD that remained statistically significant with adjustment for important covariates (HR=1.72; 1.44–2.06 and HR= 1.58; 1.37–1.83). Women with low BMD, with and without sarcopenia, respectively, had higher risk of hip fractures, (HR=2.78; 1.78–4.30 and HR=2.42; 1.63–3.59). Women with sarcopenia alone had similar HRs to women with normal BMD. Conclusion Women in their sixth decade of life with low BMD irrespective of their sarcopenia status have the highest risk of fracture compared to women with normal BMD.

Measures of Physical Performance and Muscle Strength as Predictors of Fracture Risk Independent of FRAX, Falls, and aBMD: A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study

“…A similar finding was observed in the Women’s Health Initiative,(33) and in the Health ABC study,(34) with the authors of this latter study suggesting that excess lean in excess of bone mass might be a pro-fracture state. However, this would seem to be at odds with the general adaptation of bone to muscle,(35) and excess lean mass or power over bone strength seems unlikely in older men (compared with younger athletes for example).…”

Association Between Sarcopenic Obesity and Falls in a Multiethnic Cohort of Postmenopausal Women

“…Obesity was classified as body fat percentage of 42% or greater, as recommended for women aged 60 to 79, the category most closely corresponding to the WHI population . Following a previous WHI study, we defined sarcopenia using the residual method because it has been shown to have strong correlations with lower extremity function . Sarcopenia was defined as the lowest 20 th percentile of appendicular lean mass, accounting for height and body fat.…”

Appendicular lean mass and fracture risk assessment: implications for FRAX® and sarcopenia

“…[7] Furthermore, there is increasing evidence that any predictive value of ALM for fracture is substantially attenuated by consideration of femoral neck BMD. In a recent analyses, participants of the Women’s Health Initiative (WHI) were classified into mutually exclusive groups based on BMD and sarcopenia status (defined using appendicular lean mass values corrected for height and fat mass according to Newman et al[8])[9] Whereas low BMD was associated with increased risk of hip fracture, women with sarcopenia alone were at similar risk of hip fracture to non-sarcopenic women with normal BMD, suggesting that sarcopenia alone is not predictive of this outcome. In a further WHI study, appendicular lean mass was predictive of incident hip fracture amongst 872 participants 65 years or older who met Fried’s criteria for frailty, but this association did not remain statistically significant after adjusting for total hip BMD.…”