Sarcopenia and osteoporosis are systemic features of 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.Methods
Data from 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.Results
As the severity of airflow limitation increased, the prevalence of sarcopenia increased (Ptrend < .001). Additionally, as the degree of sarcopenia became severe, the prevalence of osteopenia/osteoporosis increased (Ptrend < .001), and a significant positive correlation was noted between appendicular skeletal muscle mass and BMD (ASMI/T-score: r = 0.408; P < .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 < .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, whereas exercise and dietary intake were associated with a reduced risk only in the non-sarcopenic participants.Conclusions
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.