Prevalence of obesity in asthma and its relations with asthma severity and control

Objective

To determine the prevalence of obesity in asthmatic patients attending at an out-patient clinic, and to investigate its relationships with asthma severity and level of asthma control.

Methods

In a cross-sectional study we recruited patients aged 11 years and older with con-firmed asthma diagnosis from the outpatient asthma clinic of Hospital de Clínicas de Porto Alegre, Brazil. They underwent an evaluation by a general questionnaire, an asthma control questionnaire and by pulmonary function tests. Nutritional status was classified by body mass index (BMI).

Results

272 patients were included in the study. Mean age was 51.1 ± 16.5 years and there were 206 (74.9%) female patients. Mean BMI was 27.5 ± 5.3 kg/m², and 96 (35.3%) patients were classified as normal weight, 97 (35.7%) as overweight and 79 (29%) as obesity.There was a significant higher proportion of female than male patients (34.3% vs. 13.2%, p = 0.002) in the obesity group. There were no significant differences with respect to asthma control (p = 0.741) and severity classification (p = 0.506). The FEV₁% predicted was significantly higher in the obese than in the non-obese group (73.7% vs. 67.2%, p = 0.037). Logistic regression analysis identified sex (OR = 3.84, p = 0.002) as an independent factor associated with obesity.

Conclusions

This study showed a high prevalence of obesity in asthmatic patients. Obese andnon-obese subjects were similar in regard to asthma severity and level of asthma control. Female sex was associated with obesity in this asthma population.