N-Acetylcysteine Combined with Home Based Physical Activity: Effect on Health Related Quality of Life in Stable COPD Patients- A Randomised Controlled Trial.

Abstract

Quality of life is adversely affected in Chronic Obstructive Pulmonary Disease (COPD), due to irreversible, progressive nature of the disease and limitations of current treatment options available. One of the important aim of treatment of COPD is to improve Quality of Life (QoL). Cigarette smoke contains numerous free radicals and other oxidants. Oxidative stress has been implicated in pathogenesis, progression of disease and exacerbation in COPD. Pulmonary tuberculosis, outdoor and indoor air pollution and many others are aetiologies of COPD in non-smokers. N-Acetylcysteine (NAC) is a precursor of endogenous anti-oxidant, Glutathione (GSH) and both agents act as free radical scavengers. Exercise limitation results in poor physical performance and eventually poor QoL in COPD. To observe the combined effect of 600mg of NAC once daily and physical activity (home based) in addition to standard treatment for ten weeks, compared with placebo as control group with standard treatment. This randomised controlled trial was conducted at a tertiary care centre in Mumbai for two years from December 2011 to December 2013. Hundred patients diagnosed as stable COPD (as per Global Initiative against Obstructive Lung Disease (GOLD) 2010 guidelines) were enrolled in the study. There were 50 patients in study group and control group each. The QoL was assessed using Saint George Respiratory Questionnaire-C (SGRQ-C) initially and at the end of ten weeks. The study group was treated with NAC 600mg once a day combined with daily physical activity in addition to standard treatment. Control group patients were treated with placebo and standard treatment. At the end of 10 weeks, it was observed that, mean change in SGRQ-C was significant in "study group" as compared to "control group". Mean change in score among study group was 4.72 and the same in control was 1.32, p-value=0.007. There was significant improvement in SGRQ-C score at the end of 10 weeks and QoL in the study group (p-value-0.0001 i.e., <0.05) while improvement in SGRQ-C score and QoL score in control group was not significant (p-value=0.118 i.e., >0.05). Overall, there was statistically significant improvement in SGRQ-C score and QoL (p-value=0.03 i.e., <0.05) in the study group. From the current study, it can be concluded that N-acetylcysteine 600mg once a day and 20 minute daily walk in addition to regular treatment improves QoL in stable COPD patients.