Airway Obstruction Worsens in Young Adults with Asthma Who Become Obese

Abstract

Background Few studies have examined how developing obesity in early adulthood affects the course of asthma. Objective We analyzed lung function and asthma impairment and risk among non-obese children with asthma, comparing those who were obese in young adulthood to those who remained non-obese. Methods Post-hoc analysis of 771 subjects with mild-moderate asthma who were not obese (pediatric definition, body mass index (BMI) <95th percentile) when enrolled in the Childhood Asthma Management Program at ages 5–12 years. Subjects were then followed to age ≥ 20 years. For visits at ages ≥ 20 years, spirometry values as percent predicted and recent asthma symptom scores and prednisone exposure were compared between 579 subjects who were non-obese at all visits and 151 who obese (adult definition of BMI ≥ 30 kg/m2) on at least one visit (median number of visits when obese = 4, IQR 2–7). Results Compared to participants who were non-obese (BMI 23.4 ± 2.6 kg/m2), those who became obese (BMI 31.5 ± 3.8 kg/m2) had significant decreases in FEV1/FVC (p<0.0003) and FEV1 (p = 0.001), without differences in FVC (p=0.15) during visits at ages ≥ 20 years. For each unit increase of BMI, FEV1 percent predicted decreased by 0.29 (p=0.0009). The relationship between BMI and lung function was not confounded by sex or BMI at baseline. Asthma impairment (symptom scores) and risk (prednisone use) did not differ between the two groups. Conclusion Becoming obese in early adulthood was associated with increased airway obstruction, without impact on asthma impairment or risk.

Distinguishing characteristics of difficult-to-control asthma in inner-city children and adolescents

“…This finding is consistent with previous work that showed an association between obesity and increased morbidity and worsening pulmonary function in children with asthma, 33,34 as well as an adverse effect of obesity on corticosteroid responsiveness. 35,36 …”

Impact of pediatric obesity on acute asthma exacerbation in Japan

“…Studies showed obesity led to greater illness severity in patients with asthma . Nationwide studies in the USA revealed that obesity was associated with the use of non‐invasive or invasive mechanical ventilation among hospitalized children with acute asthma exacerbation (odds ratio, 1.59; 95% CI, 1.28‐1.99) .…”

“…Studies showed obesity led to greater illness severity in patients with asthma. 20,30 Nationwide studies in the USA revealed that obesity was associated with the use of non-invasive or invasive mechanical ventilation among hospitalized children with acute asthma exacerbation (odds ratio, 1.59; 95% CI, 1.28-1.99). 20 On the other hand, our study did not show a significant difference in the risk of intensive care, such as mechanical ventilation or intensive care unit admission, between obese and normal weight groups.…”

Sex Differences in the Relationship between Fitness and Obesity on Risk for Asthma in Adolescents

“…Several studies have shown the effects of obesity on lung function particularly airway obstruction (40;41). It would be important to evaluate for associations between pulmonary function testing, weight status and fitness levels.…”