Relationships among muscle oxidative capacity, coronary artery calcium, and hepatic steatosis in COPD: A pilot study

Introduction: COPD is characterized by inactivity and muscle deconditioning. We recently showed a negative association between muscle oxidative capacity and serum triglyceride concentrations in severe COPD. It is unclear whether these maladaptations contribute to increased cardiometabolic disease risk. Aim. To assess relationships among muscle oxidative capacity, coronary artery calcium (CAC), and hepatic steatosis (liver-to-spleen Hounsfield Unit ratio) in smokers with and without COPD. Methods. Data from 90 COPDGene subjects (GOLD 1/2/3/4=10/12/6/7; 55 smoking controls with normal spirometry) were retrospectively analyzed. CAC and L/S were assessed from chest CT. Muscle oxidative capacity was estimated from the O2 consumption recovery rate constant (k) using near-infrared spectroscopy. Results. k was lower in COPD than controls (1.31±0.44 vs. 1.67±0.45min-1; p 0.05). L/S was greater in COPD (1.45±0.49 vs. 1.31±0.26; p=0.038, d=0.36), and the threshold for fatty liver disease (L/S