Impact of Sleep Quality on the Health-Related Quality of Life of Patients with Chronic Obstructive Pulmonary Disease.

Impaired sleep is reportedly common in chronic obstructive pulmonary disease (COPD) and the impact of quality of sleep on health-related quality of life (HRQL) has been documented. Although factors affecting HRQL have been investigated in various studies, the impact of sleep quality on HRQL has not been previously investigated among patients with COPD in Nigeria. The purpose of this study was to determine the contribution of sleep quality as a factor affecting HRQL. We hypothesized that sleep quality is a determinant of HRQL.Sixty patients with COPD were evaluated. HRQL was assessed using COPD Assessment Test (CAT). Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Lung function was assessed by spirometry, severity of dyspnea by the Modified Medical Research Council (MMRC) scale, and functional exercise capacity by the Six-Minute Walk Test (6MWT). In all the statistical tests, a p value of <0.05 was considered significant.The mean age of the study population was 70±8years. Forty-nine patients (81.7%) had poor quality of sleep (PSQI > 5). The mean CAT score of the study population was 19.40±7.5. Bivariate correlation shows that HRQL reduces with worsening sleep quality (r=0.705, p=<0.001). HRQL was also associated with COPD severity (P = 0.001), severity of dyspnea, exercise capacity and frequency of exacerbation (P = <0.001). Multiple regression analysis showed that quality of sleep was the best independent predictor of HRQL in our patients (p= <0.001).Results from this study suggest that health status is generally poor in patients with COPD and quality of sleep is a significant determinant of their HRQL.