Sarcopenia and osteoporosis are systemic features of chronic obstructive pulmonary disease (COPD). The present study investigated the association between sarcopenia and osteopenia/osteoporosis, and the factors associated with low bone mineral density (BMD) in men with COPD.
Data of 777 men with COPD who underwent both pulmonary function test and dual energy X-ray absorptiometry were extracted from the Korean National Health and Nutritional Examination Survey database between 2008 and 2011. Sarcopenia was assessed with the appendicular skeletal mass index (ASMI) and osteopenia/osteoporosis with the T-score.
As the severity of airflow limitation increased, sarcopenia prevalence increased (Ptrend<0.001). Additionally, as the degree of sarcopenia became severe, osteopenia/osteoporosis prevalence increased (Ptrend<0.001), and a significant positive correlation was noted between appendicular skeletal muscle mass and BMD (ASMI–T-score: r=0.408, P<0.001). Sarcopenia was independently associated with an increased risk of low BMD in men with COPD (OR=2.31; 95%CI,1.53–3.46; P<0.001). Old age and low fat mass were significantly associated with low BMD in both sarcopenic and non-sarcopenic participants. High serum hemoglobin and insulin levels were associated with a reduced risk of low BMD only in the sarcopenic participants, while exercise and dietary intake were associated with a reduced risk only in the non-sarcopenic participants.
Sarcopenia is closely correlated with osteopenia/osteoporosis in men with COPD. Moreover, different factors are associated with low BMD according to the presence/absence of sarcopenia in that population.