Obesity and asthma: An association modified by age of asthma onset

Abstract

Background Studies of asthma phenotypes have identified obesity as a component of a group characterized by a high proportion of adult-onset asthmatics. However, whether age of asthma onset modifies the association between obesity and asthma is unknown. Methods From the Severe Asthma Project (SARP), we defined age of asthma onset as early (before 12 years of age) and late-onset (12 and higher). Comparisons of body mass index (BMI) categories were done within age of onset groups and obesity was also compared across these groups. Multivariable logistic regression analysis was done to evaluate the association between BMI categories with healthcare utilization and respiratory symptoms and multivariable linear regression for the association between duration of asthma and weight gain (BMI change/yr). An interaction between obesity and age of asthma onset was included in the multivariable analyses. Results The study population consisted on 1,049 subjects of which the median age for asthma onset was 10 years (IQR 4 – 25); 48% were late-onset (≥ 12) and 52% were early-onset (<12). Compared to late-onset obese asthmatics, early-onset obese asthmatics had more airway obstruction, bronchial hyperresponsiveness, and higher OR of ever having 3 or more oral steroid tapers preceding/year or ICU admissions for asthma/preceding year (Interactions between obesity and age of asthma onset were respectively p=0.055 and p=0.02). In early-onset, but not in late-onset asthmatics, there was a significant association between increasing BMI and duration of asthma, after adjusting for confounders. The interaction between asthma duration and age of asthma onset was p < 0.01. Conclusion Asthmatics are differentially affected by obesity, based on whether they developed asthma early (<12 years) or later in life. These results highlight the need to understand obesity as a comorbidity that affects specific clinical phenotypes and not all asthma subjects alike.

Long-term CPAP treatment improves asthma control in patients with asthma and obstructive sleep apnoea

“…Obesity and sleep apnoea are more likely to be associated with a neutrophilic asthma phenotype than an allergic and/or eosinophilic asthma phenotype, offering an explanation for the reduced probability of reaching an optimal asthma control level with traditional asthma therapy such as inhaled corticosteroids, long-acting bronchodilators and antileukotrienes [23,26,27]. Obesity has been associated with asthma both as a risk factor for asthma and as a modifying factor of the disease [28,29]. Since this was a questionnaire study we did not have the option of studying sputum samples to differentiate between eosinophilic and neutrophilic asthma phenotypes.…”

Health issues in Hispanic/Latino youth.

“…Obesity-related asthma is also associated with greater disease burden among those who developed asthma in their pre-adolescent years as compared to those who develop symptoms in adulthood (Holguin F et al, 2011). Pulmonary function decline in association with obesity is greater among those who develop asthma as pre-adolescent children and adolescents than those who develop it as adults (Lang JE et al, 2011).…”

Airway Obstruction Worsens in Young Adults with Asthma Who Become Obese

“…Longitudinal studies 5,6,7 have found that development of obesity in school age years is associated with greater incident asthma during adolescence. Several groups have found that among individuals with asthma, those who are obese have worse control, greater need for albuterol and oral corticosteroids, are more often hospitalized, have a decreased response to inhaled corticosteroids, and have lower quality of life 8,9,10,11,12 . Furthermore, weight gain worsens asthma symptoms among those with severe or difficult-to-treat asthma 13 , and weight loss improves both asthma control and lung function 14,15,16 .…”