Obesity and asthma: an association modified by age

Onset of asthma-like symptoms in children with lower respiratory tract infections

Background

Asthma‐like symptoms (ALS) often occur among children with lower respiratory tract infections (LRTIs). We aimed to determine the potential risk factors for ALS onset in LRTIs children.

Methods

A total of 102 LRTIs with ALS and 474 without ALS were enrolled. The relative risk (RR) was used to test the influence of the clinical factors on the ALS risk. We compared the differences of birth data, wheezing history, disease severity, inflammatory markers, infectious pathogens, allergic markers, cardiac, liver, and kidney injury markers between LRTIs with and without ALS onset. Receiver operating curve (ROC) analysis was applied to determine the predictive value of various markers in the ALS risk in LRTIs. Multivariate logistic regression analysis was performed to evaluate the association between various clinical and laboratory parameters and ALS onset in LRTIs.

Results

The RRs of boys/girls ratio and wheezing history for ALS compared with non‐ALS was 1.263 and 2.850, respectively (P = .026, <10⁻⁴). There were significant differences of age, WBC, PLT, EOS, and CK between LRTIs with and without ALS onset (P = .004, .041, .006, .049, and .035). ROC analysis showed that significant associations between the parameters of age, WBC, and PLT and ALS risk among LRTIs were observed. Multivariate logistic regression analysis showed that the clinical and laboratory parameters were not independently associated with the risk of ALS onset among LRTIs.

Conclusions

Lower age, male, inflammation, and allergic state were risk factors for ALS onset in LRTIs. Comprehensive monitoring and evaluation of these factors may be helpful for ALS prevention.

Obesity Does Not Increase the Risk of Asthma Readmissions

The relationship between obesity and asthma exacerbations is still under debate. The aim of our work is to analyse the relationship between obesity and hospital re-admissions in asthmatics. A review was retrospectively performed on all hospital admissions of adult patients due to asthma exacerbation occurring in our hospital for 11 years. All those cases with asthma as the first diagnosis in the discharge report were included, or those with asthma as the second diagnosis provided when the first diagnosis was respiratory infection or respiratory failure. Only the first hospital admission of each patient was included in this study. The Odds Ratios of a higher incidence of early/late readmissions due to asthma exacerbation were calculated using a binary logistic regression, using the body mass index (BMI) as independent variable, adjusted for all the variables included in the study. The study included 809 patients with a mean age of 55.6 years, and 65.2% were female. The majority (71.4%) were obese or overweight. No significant relationship was observed in the univariate or multivariate analyses between overweight or obesity and the early or late hospital readmissions due to asthma. Therefore, obesity does not seem to be a determining factor in the risk of asthma exacerbations.

Having concomitant asthma phenotypes is common and independently relates to poor lung function in NHANES 2007-2012

Background

Evidence for distinct asthma phenotypes and their overlap is becoming increasingly relevant to identify personalized and targeted therapeutic strategies. In this study, we aimed to describe the overlap of five commonly reported asthma phenotypes in US adults with current asthma and assess its association with asthma outcomes.

Methods

Data from the National Health and Nutrition Examination Surveys (NHANES) 2007-2012 were used (n = 30,442). Adults with current asthma were selected. Asthma phenotypes were: B-Eos-high [if blood eosinophils (B-Eos) ≥ 300/mm³]; FeNO-high (FeNO ≥ 35 ppb); B-Eos&FeNO-low (B-Eos < 150/mm³ and FeNO < 20 ppb); asthma with obesity (AwObesity) (BMI ≥ 30 kg/m²); and asthma with concurrent COPD. Data were weighted for the US population and analyses were stratified by age (< 40 and ≥ 40 years old).

Results

Of the 18,619 adults included, 1059 (5.6% [95% CI 5.1-5.9]) had current asthma. A substantial overlap was observed both in subjects aged < 40 years (44%) and ≥ 40 years (54%). The more prevalent specific overlaps in both age groups were AwObesity associated with either B-Eos-high (15 and 12%, respectively) or B-Eos&FeNO-low asthma (13 and 11%, respectively). About 14% of the current asthma patients were "non-classified". Regardless of phenotype classification, having concomitant phenotypes was significantly associated with (adjusted OR, 95% CI) ≥ 2 controller medications (2.03, 1.16-3.57), and FEV₁ < LLN (3.21, 1.74-5.94), adjusted for confounding variables.

Conclusions

A prevalent overlap of commonly reported asthma phenotypes was observed among asthma patients from the general population, with implications for objective asthma outcomes. A broader approach may be required to better characterize asthma patients and prevent poor asthma outcomes.

Impact of Obesity on Clinical Outcomes in Urban Children Hospitalized for Status Asthmaticus

BACKGROUND AND OBJECTIVE

The prevalence of both childhood asthma and obesity remain at historically high levels and disproportionately affect urban children. Asthma is a common and costly cause for pediatric hospitalization. Our objective was to determine the effect of obesity on outcomes among urban children hospitalized with status asthmaticus.

METHODS

A retrospective cohort study was performed by using billing system data and chart review to evaluate urban children admitted for asthma. Demographics, asthma severity, reported comorbidities, and outcomes were assessed. Obesity was defined by BMI percentile (lean<85%, overweight 85%-95%, obese≥95%). Outcomes were length of stay, hospitalization charges, ICU stay, repeat admissions, and subsequent emergency department (ED) visits. Bivariate analysis assessed for differences between overweight/obese and lean children. Multivariable regression assessed the relationship between overweight status and primary outcomes while controlling for other variables. Post hoc age-stratified analysis was also performed.

RESULTS

The study included 333 subjects; 38% were overweight/obese. Overweight/obese children admitted with asthma were more likely than lean children to have subsequent ED visits (odds ratio 1.6, 95% confidence interval 1.0-2.6). When stratified by age, overweight/obese preschool-age children (<5 years) were >2 times as likely to have repeat ED visits than lean preschool-age children (odds ratio 2.3, 95% confidence interval 1.0-5.6). There were no differences in the other outcomes between overweight/obese and lean individuals within the entire cohort or within other age groups.

School environmental factors are predictive for exercise-induced symptoms in children

BACKGROUND

Environmental factors in schools have a significant effect on the exercise-induced bronchoconstriction and symptoms in a general paediatric population.

OBJECTIVES

To determine the environmental factors such as atmospheric conditions and the presence of allergens in gymnasiums, that could be predictive of the presence of exercise-induced symptoms/bronchospasm in children during physical education (PE).

METHODS

1370 schoolchildren were enrolled. Children attended 45 min PE lesson with similar exercise intensity. Pulmonary function tests were performed before and after PE lesson. Air temperature, humidity and pressure, samples of dust for allergen exposure in the gymnasiums were taken. Children who reported symptoms induced during PE lesson were invited to the clinic for ETC (exercise treadmill challenge) and atopy measurement.

RESULTS

1033 participants were included into the analysis. Sixty seven(6.5%) children reported dyspnea/cough, and in 94(9.4%) children bronchoconstriction induced during PE lesson was documented. There is a correlation between the results of the ETC and bronchoconstriction after PE (OR: 2.55; 95%CI: 1.07-6.05; p = 0.034). Exposure to higher air pressure and higher humidity independently increase the risk of clinical symptoms reported during or after PE lesson. Exposure to cat's allergens increase the risk of bronchoconstriction (independently from atopy status). We showed significant interaction between presence of asthma and current ICS therapy as a risk of physical inactivity at school (OR: 4; 95%CI: 1.3-12; p < 0.001).

CONCLUSION

This study showed an effect of cat allergen and environmental factors (humidity, air pressure) on the appearance of exercise related cough/bronchoconstriction during activity class in a natural environment at school in a large urban population of schoolchildren.

Association of asthma with obesity among adolescents exposed to environmental tobacco smoke

OBJECTIVE

The purpose of this study was to examine the association between asthma diagnosis and obesity among adolescents exposed to environmental tobacco smoke (ETS).

METHODS

The sample included 28,807 adolescents (13-17 years old) from the National Survey of Children's Health (NSCH) (2011-2012).

STUDY DESIGN

The NSCH is a US cross-sectional telephone survey that included at least one child between the ages of 0 and 17 years residing at a household during the time of the interview. Descriptive statistics were used to describe sample characteristics and assess the prevalence of asthma among adolescents with obesity exposed to ETS. Logistic regression models were built to assess the effect of obesity on asthma diagnosis within the context of ETS exposure.

RESULTS

The prevalence of asthma among adolescents was 10.4% and the obesity was 13.2%. Adolescents with obesity exposed to ETS within the home were significantly (p < 0.05) more likely to have an asthma diagnosis (23%) compared with non-obese (10.9%) residing in similar households. Adjusted odds ratios showed that adolescents with obesity were 2.07 (95% CI, 1.15, 3.70) times more likely to have asthma if they were exposed to ETS inside their homes.

CONCLUSION

The findings indicate that adolescents with obesity are more likely to be diagnosed with asthma if they are exposed to ETS in the household. It is important that the association between obesity and asthma is examined within the context of environmental risk factors in future studies, as this may shed some light to underlying mechanisms between these two serious public health issues.