This study evaluated whether low bone density, a condition related to aging, is associated with low muscle mass, a surrogate for sarcopenia, and whether it could be used as a marker of the condition.
We studied 483 women aged 35 to 69 years old who appeared healthy and attended a preventive gynecological examination. Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD) and regional body composition. BMD was assessed using the T-score. Low appendicular lean mass (aLM) adjusted by height (aLM index) was defined according to Baumgartner et al (<5.45 kg/m2). The association of low aLM index with bone mass was evaluated with a binary logistic regression using a cutoff point on the receiver operating characteristic curves for the T-score of −1.5.
The participants had a mean age of 54.7 ± 9.1 years, body mass index of 24.6 ± 3.6 kg/m2, aLM index of 5.9 ± 0.6 kg/m2 (22.6% showed sarcopenia), abdominal fat percentage of 44.0 ± 9.1%, and T-score of −0.48 ± 0.97. In the logistic regression model, we found that low BMD implied a significant risk for sarcopenia (odds ratio [OR] 1.77; 95% CI, 1.02-3.06). In contrast, excess body weight was a protective factor (OR 0.12; 95% CI, 0.06-0.25). Neither age nor abdominal fat percentage, however, influenced the likelihood of sarcopenia in these women.
A BMD T-score below −1.5 suggests low muscle mass in middle-aged women, which is a central element in the diagnosis of sarcopenia. Early diagnosis provides the opportunity to introduce preventive and therapeutic options.
1Faculty of Medicine, Universidad de Chile, Santiago de Chile, Chile
2Department of Endocrinology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago de Chile, Chile
3Centro de Estudios Médico Ginecológico Preventivo, Santiago de Chile.
Address correspondence to: Juan E. Blümel, MD, PhD, Departamento Medicina Sur, Facultad de Medicina, Universidad de Chile, Orquídeas 1068, Dpto 302, PO BOX 7510258, Providencia, Santiago de Chile, Chile; E-mail: email@example.com
Received 28 July, 2017
Revised 30 August, 2017
Accepted 30 August, 2017
Financial disclosure/conflicts of interest: None reported.