Effects of nutritional supplementation combined with conventional pulmonary rehabilitation in muscle-wasted chronic obstructive pulmonary disease: a prospective, randomized and controlled study

Background and objective: Nutritional depletion in chronic obstructive pulmonary disease (COPD) adversely affects health status and mortality. We aimed to evaluate the effects of nutritional supplementation (NS) with pulmonary rehabilitation (PR) on body composition, mid-thigh cross-sectional area (CSA), dyspnoea, exercise capacity, health-related quality of life, anxiety and depression in advanced COPD patients.

Methods: Forty-six patients were randomized to PR and nutritional support (PRNS), PR or the control group. Dyspnoea was measured with Medical Research Council and BORG scales. Exercise capacity was measured through 6-min walk test and shuttle tests; health-related quality of life was assessed with St. George's Respiratory Questionnaire. Psychological status was measured with Hospital Anxiety and Depression Scale. Body weight and body mass indexes (BMI) were also evaluated. Fat-free mass was measured through bioelectrical impedance analyser. The CSA of quadriceps was calculated in mid-level of the thigh with magnetic resonance imaging.

Results: Dyspnoea and total scores of St. George's Respiratory Questionnaire improved in both groups (P < 0.05). Six-minute walk test and incremental shuttle walk test distances in PRNS and PR patients increased significantly as (62.6 ± 42.4 m, 43.3 ± 59.2 m, both P = 0.001; and 63.3 ± 70.1 m and 69.3 ± 69.7 m, both P = 0.001). Although anxiety improved in both groups (P < 0.05), there was no change in depression. Body weight, BMI and fat-free mass index (FFMI) (1.1 ± 0.9 kg, 0.2 ± 1.4 kg/m(2) and 0.6 ± 0.5 kg/m(2), P < 0.05) in PRNS, whereas body weight and FFMI (0.6 ± 0.7 kg, 0.1 ± 0.6 kg/m(2) P < 0.05) increased in PR after the intervention. There was a significant increase in mid-thigh CSA (2.5 ± 4.1 cm(2)) only in PRNS (P = 0.04).

Conclusion: The combination of NS with PR resulted in improvements particularly in lean body mass and mid-thigh CSA. This study suggests combining NS with PR in reversing weight loss and muscle wasting in COPD.