Health-related quality of life in obesity

Abstract

Aims: to document the impact of obesity on health-related quality of life (HRQL), to evaluate the effects of weight reduction treatment on HRQL, and to validate and improve methods for the assessment of HRQL in obesity. Methods: a) SOS comprises a cross-sectional study, an ongoing prospective intervention trial, and a longitudinal population study (n=1135). 6328 obese individuals in the cross-sectional study completed comprehensive questionnaires and were health examined. Inclusion criteria were age (37-57 years) and BMI ³ 34 kg/m2 for males and BMI ³ 38 kg/m2 for females. The intervention study includes a surgically treated group (n=2010) and a group of matched controls (n=2038) that are offered conventional treatment at primary health care centers. Patients are followed regularly for 20 y. b) Sixty moderately obese women participating in a separate diet intervention study were followed for two years. c) XENDOS is a randomized, placebo-controlled, double-blind clinical trial of effects of medical treatment. 3305 obese subjects (BMI ³ 30 kg/m2), aged 30-60 y, were followed for 4 years. Standardized HRQL instruments were used for assessment of mental wellbeing, general health, psychosocial functioning, functional health limitations, and eating behavior. Results: The severely obese rated their HRQL markedly worse than the population norm. A high proportion of the severely obese was bothered because of their obesity in everyday life activities. Women reported more weight-related psychosocial problems than men. General health and mental wellbeing was poor and a large proportion exceeded the cut-off values for probable cases of morbid anxiety and depression. Weight loss in moderately obese women was accompanied by improvements in mood, while weight regain was followed by a marked decline. Subjective assessment of long-term success (assessed after 3 weeks of dieting) predicted weight loss. Uncontrolled eating and functional limitations prior to treatment predicted weight regain. HRQL was markedly improved after weight reduction surgery. Improvements after two and four years were positively related to the amount of weight loss, i.e., greater weight reduction resulted in greater improvements in functioning and wellbeing. A distinct dose-response effect between weight reduction and improvements in psychosocial functioning was observed. HRQL in the weight stable conventionally treated patients was not improved. The refinement of methods included a modified 18-item eating behavior questionnaire derived from the original 51-item version. The revised measurement model comprises three constructs for the assessment of uncontrolled eating, restraint eating and emotional eating. Emotionally induced eating problems were associated with mental distress. Conclusions: Severe obesity has a profound negative effect on HRQL. Weight reduction after surgery improves HRQL and the effect is positively related to the amount of weight loss. Obesity-related HRQL modules are the most effective outcome measures.