Absolute appendicular lean mass best predictor of osteoporosis in menopause
Absolute appendicular lean mass appears to be a suitable marker for predicting osteoporosis based on low muscle mass for postmenopausal women, according to findings published in Menopause.
“Prior studies have noted that different cutoff points based on the normalization of appendicular lean mass by height and BMI are responsible for the difference between sexes in skeletal muscle mass loss rate and prevalence of low muscle mass and the inconsistent results between sarcopenia and risk of fracture,” Camila Miranda, MSc, of the Applied Physiology, Aging, Nutrition and Exercise Research Group at Federal University of Triângulo Mineiro in Uberaba, Brazil, and colleagues wrote. “The current study contributes to the growing body of evidence, indicating that inconsistent results are also observed between different cutoff points of appendicular lean mass and osteoporosis in postmenopausal women.”
In a cross-sectional study, Miranda and colleagues analyzed data from postmenopausal women classified for presence of osteoporosis at the femoral neck and lumbar spine and three cutoff points for low muscle mass: appendicular lean mass of less than 15 kg; appendicular lean mass/height2 (appendicular lean mass index) of less than 5.67 kg/m2; and ratio between appendicular lean mass and BMI of less than 0.512.
After adjustments for confounding factors, binary logistic regression showed that appendicular lean mass and appendicular lean mass index were associated with osteoporosis at the lumbar spine, with ORs of 5.3 (95% CI, 2.3-12.5) and 2.5 (95% CI, 1-6.2), respectively. Only appendicular lean mass was associated with osteoporosis at the femoral neck, with an OR of 16.1 (95% CI, 4.1-62.5).
When women were classified as having osteoporosis in at least one site, only appendicular lean mass was associated with osteoporosis, with an OR of 7.7 (95% CI, 3.3-15.6).
There was no association between appendicular lean mass to BMI ratio and osteoporosis. The predictive value of appendicular lean mass for osteoporosis decreased after BMI or height was included as a covariate in the model.
“The predictive value for osteoporosis based on appendicular lean mass is reduced by adjustment for BMI and height measures,” the researchers wrote. “Thus, the use of absolute appendicular lean mass (<15 kg) seems to be the most suitable for predicting osteoporosis based on low muscle mass in postmenopausal women.”