Clinical and psychological correlates of health-related quality of life in obese patients

Background: Health-related quality of life (HRQL) is poor in obese subjects and is a relevant outcome in intervention studies. We aimed to determine factors associated with poor HRQL in obese patients seeking weight loss in medical units, outside specific research projects. Methods: HRQL, together with a number of demographic and clinical parameters, was studied with generic (SF-36, PGWB) and disease-specific (ORWELL-97) questionnaires in an unselected sample of 1,886 (1,494 women; 392 men) obese (BMI > 30 kg/m(2)) patients aged 20-65 years attending 25 medical units scattered throughout Italy. The clinics provide weight loss treatment using different programs. General psychopathology (SCL-90 questionnaire), the presence of binge eating (Binge Eating scale), previous weight cycling and somatic comorbidity (Charlson's index) were also determined. Scores on SF-36 and PGWB were compared with Italian population norms, and their association with putative determinants of HRQL after adjustment for confounders was assessed through logistic regression analysis. Results: HRQL scores were significantly lower in women than in men. A greater impairment of quality of life was observed in relation to increasing BMI class, concurrent psychopathology, associated somatic diseases, binge eating, and weight cycling. In multivariate analysis, psychopathology (presence of previously-diagnosed mental disorders and/or elevated scores on SCL-90) was associated with lower HRQL scores on both psychosocial and somatic domains; somatic diseases and higher BMI, after adjustment for confounders, were associated with impairment of physical domains, while binge eating and weight cycling appeared to affect psychosocial domains only. Conclusions: Psychopathological disturbances are the most relevant factors associated with poor HRQL in obese patients, affecting not only psychosocial, but also physical domains, largely independent of the severity of obesity. Psychological/psychiatric interventions are essential for a comprehensive treatment of obesity, and to improve treatment outcome and to reduce the burden of disease.