Normal Weight but Low Muscle Mass and Abdominally Obese: Implications for the Cardiometabolic Risk Profile in Chronic Obstructive Pulmonary Disease.

Background: It is well established that low muscle mass affects physical performance in chronic obstructive pulmonary disease (COPD). We hypothesize that combined low muscle mass and abdominal obesity may also adversely influence the cardiometabolic risk profile in COPD, even in those with normal weight. The cardiometabolic risk profile and the responsiveness to 4 months high-intensity exercise training was assessed in normal-weight patients with COPD with low muscle mass stratified by abdominal obesity.

Methods: This is a cross-sectional study including 81 clinically stable patients with COPD (age 62.5 ± 8.2 years; 50.6% males; forced expiratory volume in 1 second 55.1 ± 19.5 percentage predicted) with fat-free mass index <25th percentile eligible for outpatient pulmonary rehabilitation. Body composition, blood biomarkers, blood pressure, physical activity level, dietary intake, and physical performance were assessed at baseline and in a subgroup after 4 months of exercise training.

Results: Mean body mass index was 22.7 ± 2.7 kg/m, and 75% of patients had abdominal obesity. Abdominally obese patients had higher glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), branched chain amino acids and a higher prevalence of metabolic syndrome compared with those without abdominal obesity. Exercise training improved cycling endurance time and quadriceps strength, but did not yield a clinically meaningful improvement of the cardiometabolic risk profile. Triglycerides showed a significant decrease, while the HOMA-IR increased.

Conclusion: Abdominal obesity is highly prevalent in normal-weight patients with COPD with low muscle mass who showed an increased cardiometabolic risk compared with patients without abdominal obesity. This cardiometabolic risk profile was not altered after 4 months of exercise training.