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    ABSTRACT: Abstract Objective: Increases in asthma and obesity over the past three decades have led to speculation about a causal link between the two diseases. However, investigations of the relationship between body mass index (BMI) and fractional exhaled nitric oxide (FeNO) - a marker of eosinophilic airway inflammation - have produced mixed results. The purpose of this study was to evaluate the relationship between BMI, asthma and FeNO in a sample of U.S. adults using data from the National Health and Nutrition Examination Surveys (NHANES) for 2007-2010. Methods: We assessed the relationship between FeNO and BMI in subjects with and without asthma using categorical and continuous models for BMI. All models controlled for age, gender, ethnicity, household income-to-poverty ratio, atopy and current smoking. Results: Adjusted asthma prevalence was positively associated with BMI, and subjects with asthma had higher adjusted FeNO levels than subjects without asthma. However no association between FeNO and BMI was observed in either those with (̂β = 0.002, p = 0.74) or without (̂β = 0.0014, p = 0.51) asthma after adjusting for covariates. Conclusions: Our results suggest that in the U.S. adult population, BMI is not associated with eosinophilic airway inflammation.
    Journal of Asthma 04/2014; · 1.83 Impact Factor
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    ABSTRACT: ABSTRACT Obesity and asthma are both important public health issues. Increasing number of studies suggest the association between obesity and asthma which may be causal or accidental. The studies on animal models show innate enhancement of airway hyper-responsiveness which suggest that chronic airway hyper-responsiveness may be related to chronic low-grade systemic inflammation occurring in obesity. These results are confirmed by studies on asthmatic patients which show that levels of inflammation markers were higher in obese asthma patients and are related to the parameters of obesity. However, adipokines secreted by adipose tissue have also been involved in the regulation of inflammation and allergic responses, and suggested to affect the risk of asthma, especially in obese female patients. The studies on the association between adiposity and atopy have conflicting results and the issue needs to be investigated in the future. Obesity also decreases lung volume and increases airway resistance inducing symptoms that could mimic asthma. Clinical studies suggest that asthma in obese subjects may differ from the classical phenotype of the disease. Obese patients referred for asthma exacerbation present a reduced response to standard asthma medications. The review indicates that mechanical and inflammatory effects of obesity may explain the influence on asthma. Further studies on the association between adiposity and atopy on airway inflammation may confirm the active role of fat tissue, not only simple mechanical impairment of the thorax movement. Longitudinal studies are needed to understand the association between asthma, and obesity, which may open new therapeutic options for asthma treatment in obese patients.
    Advances in Medical Sciences 05/2013; · 0.80 Impact Factor
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    ABSTRACT: The prevalence and incidence of asthma have increased among obese children and adults, particularly among women. Obesity seems to be a predisposing factor for the development of asthma, but the underlying mechanisms of its influence are still uncertain. Various hypotheses have been proposed to explain the link between obesity and asthma such as a common genetic predisposition, developmental changes, altered lung mechanics, the presence of a systemic inflammatory process, and an increased prevalence of associated comorbid conditions. Over-diagnosis of asthma does not seem to be more frequent in obese compared to non-obese subjects, but the added effects of obesity on respiratory symptoms can affect asthma control assessment. Obesity can make asthma more difficult to control and is associated with a reduced beneficial effect of asthma medications. This could be due to a change in asthma phenotype, particularly evidenced as a less eosinophilic type of airway inflammation combined to the added effects of changes in lung mechanics. Weight loss is associated with a universal improvement of asthma and should be part of asthma management in the obese patient. Additional research should be conducted to better determine how obesity influences the development and clinical expression of asthma, establish the optimal management of asthma in this population and determine how obesity affects long-term asthma outcomes in these patients.
    Clinical & Experimental Allergy 01/2013; 43(1):8-21. · 4.32 Impact Factor