Is obesity a significant impacting factor of asthma control?

ABSTRACT

OBJECTIVE: To measure the control of bronchial asthma, quality of life, trigger factors and co-morbidities in patients of different weight classes. SUBJECTS AND METHODS: This cross-sectional study involved 365 adult asthmatics from outpatient clinics at four major health facilities in Trinidad. Data were obtained from patient interviews, asthma control test (ACT) and the Mini Asthma Quality of Life Questionnaire (Mini AQLQ). Weight and height measurements were taken to determine body mass index (BMI), waist circumference and waist/hip ratio. Data obtained were analysed to determine associations between obesity and asthma control, associated co-morbidities, risk factors and impaired quality of life. RESULTS: A significant number of participants was females(81%), aged 60+ years (37%), Indo-Trinidadians (62%),obese (41%) and uncontrolled asthmatics (72%). Chisquared analysis revealed significant association between obesity and asthma control status (5.810; df = 1; p =0.016). Receiver operating characteristic analysis revealed BMI (AUC = 0.648) as the strongest predictor of asthma control among all obesity parameters. Logistic regression showed that higher BMI (OR = 1.05; p = 0.008) or general obesity (OR = 2.37; p = 0.003) were significantly associated with the increased odds of having uncontrolled asthma. Major trigger factors and co-morbidities were similar among obese and non-obese asthmatics. Sub analysis of obese asthmatics showed that the following were significantly associated with poor asthma control sleep apnoea (OR = 0.45, p = 0.006), allergic rhinitis (OR= 0.562, p = 0.031) and stress (OR = 0.480, p = 0.027). CONCLUSION: Obesity negatively affects asthma control and the quality of life of asthmatics. Further studies are needed to confirm these findings and to evaluate the role of weight reduction in asthma control.