Background: Pulmonary Rehabilitation ("Rehabilitation") can improve both lung function and quality of life in patients suffering from chronic obstructive pulmonary disease (COPD) even if only a very small proportion of patients have access to Rehabilitation. Supplementation of Essential Amino Acids (EAAs) might allow COPD patients to achieve some typical Rehabilitation outcomes such as a better physical performance and an improved health status.
Methods: 88 COPD out-patients (GOLD class 3-4) with a body mass index (BMI) < 23 Kg/m2 were randomised to receive EAAs (n = 44) or placebo (n = 44) for twelve weeks. Primary outcome measures were changes in both physical activities in daily life (measured by Sense Wear Armband in terms of mean steps walked in one week) and in quality of life (measured by the St George's Respiratory Questionnaire, SGRQ).
Results: After 12 weeks, the physical performance was significantly increased vs baseline only in patients who received EAAs (1140.33 +/- 524.69 and 638.68 +/- 662.1 steps/day, respectively; p = 0.02), being also the comparison vs the placebo group highly significant (p = 0.003). Similarly, the SGRQ score improved significantly only in EAA patients (69.35 +/- 9.51 vs baseline 72.04 +/- 8.62; p < 0.01), and changes were significantly different from those measured in the placebo group (p < 0.001). Furthermore, when compared to those who received placebo, EAAs patients significantly increased their fat-free mass (p = 0.04), muscle strength (p < 0.01), saturation of oxygen (p = 0.05), serum albumin (p < 0.001), and also ameliorated their original cognitive dysfunction (p = 0.02).
Conclusions: Oral supplementation with EAAs contribute to improve the daily-life performance in domiciliary severe COPD patients who can not enter any Rehabilitation programme, together with their quality of life; nutritional and cognitive status, and muscle strength.