Effect of Dietary Supplementation on Body Composition, Pulmonary Function and Health-Related Quality of Life in Patients with Stable COPD

Abstract

Background: Malnutrition is very common in patients with chronic obstructive pulmonary disease (COPD). Nutritional supplementation improves the patient's nutritional status by increasing the energy intake and providing anti-inflammatory elements which can relieve the patient's symptoms and delay the disease progression. This study sought to determine if energy and protein supplementation improves physical function, pulmonary function and health-related quality of life (HRQL) in stable COPD patients.

Materials and methods: The study was carried out in an outpatient setting on 60 stable COPD patients over a period of one year. Patients were randomized to intervention group (n=30), receiving supplemental nutrition in the form of additional protein and carbohydrates or control group (n=30), receiving only the usual standard diet. Lung function, body mass index (BMI), exercise capacity (6-minute walk test or 6MWT), mid-upper arm circumference (MUAC) and skin fold thickness (SFT) were evaluated, and clinical assessment was carried out at baseline and after completion of 12 weeks. The HRQL was assessed using Seattle obstructive lung disease questionnaire.

Results: Twelve weeks of dietary supplementation resulted in a significant increase in weight and BMI of patients in the intervention group in comparison to the control group (P<0.005). Significant improvement was also observed in 6MWT and HRQL scores after nutritional intervention (P=0.002 and P=0.001, respectively). However, difference in MUAC, SFT and serum protein level after 12 weeks of follow up was not significant in any of the two groups. There was a similar degree of lung function improvement in both groups although it was not statistically significant.

Conclusion: Nutritional supplementation with high protein and energy diet during 12 weeks of intervention improved body weight and composition, exercise capacity and quality of life in stable COPD patients.

Keywords: COPD, Quality of life; Dietary supplementation; Exercise capacity; Pulmonary function.

Figure 1.

Correlation between the significant functional parameters (HRQL, 6MWT) observed in the intervention group after 12 weeks. The Pearson’s correlation test was used to calculate r values.