Impact of obesity on health-related quality of life in patients with chronic illness

OBJECTIVE: To determine the association between overweight and obesity and health-related quality of Life (HRQOL) in patients with chronic conditions typical of those seen in general medical practice, after accounting for the effects of depression and medical comorbidities. DESIGN: Cross-sectional analysis of data from the Medical Outcomes Study. SETTING: Offices of physicians practicing family medicine, internal medicine, endocrinology, cardiology, and psychiatry in three U.S. cities. PATIENTS: We surveyed 2,931 patients with chronic medical and psychiatric conditions. The patients completed a self-administered questionnaire at enrollment and had complete data on height and weight. MEASUREMENTS AND MAIN RESULTS: Body mass index (BMI), chronic medical conditions, and depression were obtained by structured interview. Health-related quality of life was measured by the SF-36 Health Survey. Patients who were overweight (BMI 25.0-29.9 kg/m(2)), patients with class I obesity (BMI 30.0-34.9 kg/m(2)), and patients with class II-III obesity (BMI greater than or equal to 35 kg/m(2)) had significantly lower adjusted physical function scores (by 3.4, 7.8, and 13.8 points. respectively) compared with nonoverweight patients, Patients with class I and class II-III obesity also had significantly lower adjusted general health perceptions scores (by 2.8 and 4.4 points, respectively) and lower adjusted vitality scores (by 4.0 and 7.1 points, respectively), compared with nonoverweight patients. No significant differences between nonoverweight, overweight, and obese patients were observed for the mental health scale. Women with elevated BMI had significantly lower HRQOL scores compared with the scores of obese men in several domains. Additionally, blacks with elevated BMI had significantly lower scores than whites in several domains of HRQOL. CONCLUSIONS: Overweight and obesity have the largest association with physical function measures. Recent national standards, which have lowered the threshold for defining overweight, identify patients who are more likely to have clinically significant reductions in HRQOL and functional impairment.