Risk for asthma is associated with higher BMI, but not with obesity?

Introduction: Asthma and obesity impact the public health and their prevalence has increased in recent years. Studies show that obesity is a risk factor for asthma. Obesity is capable of reducing pulmonary compliance, lung volumes and the increase in adipose tissue metabolism in the obese leads to a systemic proinflammatory state. Aims and objectives: To assess the effect of increased BMI on the risk for asthma and levels of inflammation in asthmatic children. Methods: Of 2000 children, a cohort of 475 children and adolescents with asthma, was recruited. The participants underwent physical examination, blood sampling and lung function tests for detection of biomarkers of inflammation. We clinically assessed their health status and treatment outcome over the period of 12 months at 3 time points. Results: Participants were categorized into 4 groups according to BMI percentile: underweight, normal, overweight and obese. Increased BMI was more prevalent in male participants, both overweight and obese. At baseline, levels of hsCRP were elevated both in overweight and obese, compared to children with normal BMI. When treatment success was assessed by changes in airway inflammation after 6 months,FeNO levels were higher in bad responders, compared to good responders. Finally, we assessed the risk for asthma in all 4 groups: it was higher in overweight children compared to those with normal BMI, but not in obese. Conclusions: Although obesity is capable of increasing the prevalence of asthma in children, this effect appears to be insufficient alone. Increased BMI (overweight) increases the risk for asthma. Obesity rather increases the level of inflammation and affects the level of disease control and response to treatment.