engleski

Risk for asthma is associated with overweightness, but not with obesity?

Both asthma and obesity have a considerable impact on public health and their prevalence has increased significantly in recent decades. Previous studies have indicated that overweightness and obesity are a risk factor for asthma. Obesity is capable of reducing pulmonary compliance, lung volumes and the ventilation- perfusion relationship. Furthermore, the increase in the normal functioning of adipose tissue in obese subjects leads to a systemic proinflammatory state, resulting in the rise in serum concentrations of several mediators of inflammation, including certain cytokines (IL-6, IL-10), TNF-alpha, TGF-beta1, C-reactive protein etc. To assess the effect of higher BMI (percentile of height and weight) on the risk for asthma and levels of inflammation in asthmatic children. We have recruited 2000 children (asthmatics and non- asthmatics) as a part of routine clinical visits. A cohort of 475 children and adolescents with asthma, aged 2-22 years, was then studied in detail. The participants underwent physical examination, basic anthropometric measurements (height and weight), 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 the point of diagnosis of asthma, after 6 months and after 12 months. All participants were categorized into 4 groups according to BMI percentile: underweight (0-3 centile), normal (5-85 centile), overweight (85-95 centile) and obese (>95 centile). Increased BMI was more prevalent in male participants, both overweight and obese (14, 39% and 15, 09%, respectively) than in female (11, 05% and 12, 11%, respectively), as well as in younger children: preschool (12, 20 % overweight and 14, 63 % obese) and school children (15, 93 % overweight and 15, 93 % obese) compared to pubescent a and adolescents (9, 89% and 10, 99 %, respectively). At baseline, levels of hsCRP (high-sensitivity C-reactive protein) were elevated both in overweight (p=0, 0002) and obese (p=0, 0001) participants, compared with children with normal BMI. When treatment success was assessed by changes in airway inflammation (fraction of exhaled nitric oxide, FeNO) after 6 months, increased FeNO levels were more frequent in inadequate and bad responders, compared to children with good response to treatment (p=0, 0337). Finally, we assessed the risk for asthma in all 4 groups in all 2000 children: it was higher in overweight participants (p=0, 048, RR=1, 146, 95% CI= 1, 009, 1, 303) compared to children with normal BMI, but not in obese. Although most studies point out that obesity is capable of increasing the prevalence and incidence of asthma, this effect appears to be insufficient in the development of asthma alone. Increased BMI (overweightness, 85-95 centile) increases the risk for asthma and obesity (>95 centile) we believe rather increases the level of airway and systemic inflammation and thus potentially affects the level of disease control and response to common asthma treatment.

overweightness ; asthma ; children

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