Nutritional status and muscle mass loss in patients with COPD, association with lung function, symptoms, comorbidities and long-term survival: data from the National Database Study.

Aim: To assess nutritional status and muscle mass loss in patients with chronic obstructice pulmonary disease (COPD) from the Czech National Database of COPD and to evaluate the association of nutritional parameters with COPD phenotype, lung function, COPD-related symptoms and long-term survival.

Methods: A total of 343 patients with known body composition parameters - body mass Index (BMI), fat-free mass index (FFMI) and mid-art muscle circumference (MAMC) - were included in the analysis. Descriptive statistical methods were used to assess differences between groups, and overall survival was assessed using the Kaplan-Meier method after 9 years of follow-up.

Results: Nutritional imbalances were common in patients with COPD. Underweight and muscle mass loss were associated with emphysematous and pulmonary cachexia phenotypes, worse lung function, more symptoms and exacerbations, osteoporosis and depression. Overweight and obesity were associated with a chronic bronchitis phenotype and cardiovascular and metabolic comorbidities. Obese patients had higher forced exspiratory volume in 1 second (FEV) and diffusing capacity of the lung for carbon monoxid (DL), but lower forced exspiratory capacity (FVC). Malnutrition increased the risk of death. Cachexia and underweight reduced median survival from 72.0 to 43.5 (P=0.049) and 39.8 (P=0.010) months, respectively, compared to normal nutrition. Muscle mass loss by MAMC of ≥20% was the strongest predictor of mortality, increasing the risk of death by 5.5-fold compared to patients with normal muscle mass (P<0.001). Patients with overweight and obesity had a 40% (P=0.026) and 30% lower risk of death, respectively, compared to patients with normal nutrition.

Conclusions: Patients with COPD often have nutritional imbalances. That is an important determinant of clinical characteristics and outcomes in patients with COPD. Further research is needed to better understand these differences.