Health status assessment in patients with COPD: The contribution of BMI

OBJECTIVE To assess possible Delta-changes in the health status of patients with chronic obstructive pulmonary disease (COPD) over time, and specifically the contribution of body mass index (BMI). METHOD A prospective study was made of 50 patients with already diagnosed COPD in a private medical care setting. The impact of COPD-related symptoms on their health status was assessed using the COPD Assessment Test (CAT), which consists of 8 questions with Likert-type responses of 0-5, with a total score of 0-40; a higher CAT score indicates a greater burden on the health status. The BMI of the participants was assessed as follows: normal (18.5-24.9), overweight (25-29.9) and obese (>= 30) Delta-changes in the CAT score were assessed by three measurements over a 6-month period. Correlation between the CAT score and BMI was assessed using the Kruskal Wallis method and simple linear logistic regression. A p-value of <= 0.05 was considered statistically significant. RESULTS About half of the patients (52%) were aged 65 years and over and 42% were overweight or obese and smokers at enrolment. A significant improvement in the health status of patients with COPD was observed from the 1st to the 2nd and 3rd measurements (mean 12.5 +/- 7.4, 10.4 +/- 7.2, and 8.1 +/- 7.2, respectively, p<0.001). The BMI was significantly associated with Delta changes in health status between measurements: 3rd-1st, p=0.025 and 3rd-2nd, p=0.039 (y=-12.5+ 0.28* x, p=0.049), showing a linear trend; specifically, patients with a greater BMI had higher health status scores, but to a significant degree only for patients with normal BMI. CONCLUSIONS The maintenance of normal body weight significantly improves the health status in the daily life of patients with COPD.