Depression and obesity in adults with asthma: multiple comorbidities and management issues

OBJECTIVE: To examine the comparative prevalence and distribution of obesity and psychological disturbance in the asthma and non-asthma populations, and to determine how these comorbidities are associated with physical functioning. DESIGN, SETTING AND PARTICIPANTS: A South Australian population-representative study of 3175 adults who provided data on asthma, psychological morbidity, physical functioning, and body mass index. Bivariate and multivariate analyses identified how these comorbidities were distributed in asthma and non-asthma subpopulations, and the variance in physical functioning that they explained. MAIN OUTCOME MEASURES: Rates of obesity and psychological morbidity, and physical functioning scores in asthma and non-asthma populations. RESULTS: Men and women in the asthma population had similar prevalences of obesity (35.3% v 33.6%) and psychological morbidity (29.5% v 29.4%). When compared with non-asthma controls, both comorbidities were significantly higher only in men with asthma. The prevalence of psychological morbidity within different weight categories in the asthma population compared with non-asthma weight-category controls varied by sex. Physical functioning was lower in the asthma population than the non-asthma population (46.6 95% CI, 45.9-47.3 v 48.8 95% CI, 47.8-50.0; P < 0.001), and psychological morbidity explained 22% of this variance. CONCLUSIONS: Psychological morbidity and obesity are common in people with asthma. The sex-specific variation in psychological morbidity across weight categories suggests that future studies of psychological morbidity in groups with asthma should adopt designs that consider sex-specific controls rather than comparisons between the sexes.