Both generic and disease specific health-related quality of life are deteriorated in patients with underweight COPD.

This study evaluated the effects of body weight on both generic and disease-specific health-related quality of life (HRQoL) of patients with COPD. A total of 83 patients with stable COPD were enrolled (mean age: 74.6 yr, mean FEV1: 1.29 L). Patients were divided into two groups according to body mass index (BMI) (UW group: BMI < or = 20, NW group: 20 < BMI < or = 26). The degree of dyspnea and both disease-specific and generic HRQoL were compared between the two groups. An oxygen cost diagram (OCD) was used to assess the degree of dyspnea and St. George's Respiratory Questionnaire (SGRQ) and Medical Outcomes Study Short Form 36-item Questionnaire (SF-36) were used for HRQoL evaluation. The OCD was significantly lower in the UW group. Compared with the NW group, the UW group showed significant deterioration in the total score and three subscales of SGRQ. SF-36 also showed significantly worse scores for the parameters of physical functioning, role emotional, bodily pain, and general health. The results of stepwise multiple regression analysis showed that OCD, FEV1, %pred. BMI were independent variables in the total score on SGRQ. The results of stepwise multiple regression analysis also showed that OCD was an independent variable for four of eight components of SF-36, while BMI was three of eight components of SF-36. In conclusion, low body weight in patients with COPD is related to a worsening of dyspnea and deterioration of both generic and disease-specific HRQoL. The present results also indicate that nutritional intervention may be important for improving dyspnea and HRQoL in patients with COPD.