Female gender is associated with higher incidence and more stable respiratory symptoms during adolescence

Sex differences in sociodemographic, clinical, and laboratory variables in childhood asthma: A birth cohort study

BACKGROUND

There are marked sex differences in the prevalence and severity of asthma, both during childhood and adulthood. There is a relative lack of comprehensive studies exploring sexdifferences in pediatric asthma cohorts.

OBJECTIVE

To identify the most relevant sex differences in sociodemographic, clinical, and laboratory variables in a well-characterized large pediatric asthma cohort.

METHODS

We performed a cross-sectional analysis of the Mayo Clinic Olmsted County Birth Cohort. In the full birth cohort, we used a natural language-processing algorithm based on the Predetermined Asthma Criteria for asthma ascertainment. In a stratified random sample of 300 children, we obtained additional pulmonary function tests and laboratory data. We identified the significant sex differences among available sociodemographic, clinical, and laboratory variables.

RESULTS

Boys were more frequently diagnosed with having asthma than girls and were younger at the time of asthma diagnosis. There were no sex differences in relation to socioeconomic status. We identified a male predominance in the presence of a tympanostomy tube and a female predominance in the history of pneumonia. A higher percentage of boys had a forced expiratory volume in 1 second/forced vital capacity ratio less than 0.85. Blood eosinophilia and atopic sensitization were also more common in boys. Finally, boys had higher levels of serum periostin than girls.

CONCLUSION

This study described significant sex differences in a large pediatric asthma cohort. Overall, boys had earlier and more severe asthma than girls. Differences in blood eosinophilia and serum periostin provide insights into possible mechanisms of the sex bias in childhood asthma.

A systematic review and meta-analysis of the prevalence and epidemiology of asthma in people over 14 years of age in China

OBJECTIVE

Asthma is a common chronic respiratory disease that seriously affects the health of adults and children. The risk factors for asthma are constantly changing; thus, it is necessary to study the prevalence of asthma and risk factors in different populations. Currently, there have been no epidemiological studies on the prevalence and risk factors of asthma in people over 14 years in mainland China. Therefore, we performed a meta-analysis of the prevalence and risk factors for asthma in mainland China.

METHODS

A literature search was conducted for studies on the epidemiology of asthma in China between 2000 and 2020 using English and Chinese databases. Prevalence and epidemiological information on asthma in people aged >14 years were extracted. Meta-analysis was performed using a random-effects model (If I2>50%) with 95% confidence intervals for forest plots.

RESULTS

Nineteen studies (including data from 345,950 samples) met our evaluation criteria. The overall prevalence of asthma in Chinese adults is 2%, without differences between Northern and Southern China. The prevalence increased after 2010 compared with that before 2010. The prevalence of asthma also increased with age, with people aged 55-64 years being the most affected. The prevalence of asthma was independent of sex and residence area. In conclusion, the prevalence of asthma among adolescents (age >14 years) and adult population in China has increased since 2010.

CONCLUSION

Further studies are necessary to monitor the prevalence of asthma in mainland China. The elderly population also has a high prevalence of asthma, which should be focused on more in the future.

Potential sex differences in human milk leptin and their association with asthma and wheeze phenotypes: Results of the Ulm Birth Cohorts

BACKGROUND

The hormone leptin has been suggested to play a role in the respiratory and immune systems. Evidence on sex-specific concentrations of leptin in human milk and sex-specific associations with the development of asthma and wheeze has been put forward but is still scarce.

OBJECTIVE

To investigate whether male and female infants receive different levels of leptin through human milk and whether leptin is implicated in the development of asthma and wheeze in a sex-dependent manner using data from the two Ulm Birth Cohort studies.

METHODS

Leptin data were available from human milk samples collected at 6 weeks (Ulm Birth Cohort Study [UBCS, n = 678; Ulm SPATZ Health Study, n = 587]), and, in SPATZ only, at 6 months (n = 377) and 12 months (n = 66) of lactation. Sex-specific associations with doctor-diagnosed asthma and wheeze phenotypes were assessed in crude and adjusted models using logistic regression. Adjustments were made for maternal allergy, exclusive breastfeeding, infant age at the time of milk sampling, and child BMI z-score.

RESULTS

At 6 weeks, leptin levels (median [min, max], in ng/L) were higher in the milk for girls (197 [0.100, 4120]) than in milk for boys (159 [1.02, 3280], p = .045) in UBCS. No significant sex differences were observed in SPATZ (p = .152). There were no significant associations of leptin with asthma or wheeze in both studies, even in a sex-dependent manner (p > .05).

CONCLUSION

It remains unclear whether male and female infants receive different levels of leptin through human milk. However, leptin in human milk may not be associated with history and development of asthma and wheeze in a sex-specific manner.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

Childhood onset asthma is associated with lower educational level in young adults - A prospective cohort study

BACKGROUND

Asthma is associated with low socioeconomic status among both children and adults, and adolescents with asthma report more school absenteeism than those without. However, it is unclear whether asthma in childhood and adolescence affects socioeconomic status in adulthood.

METHODS

Within the Obstructive Lung disease In Northern Sweden Studies, all children in grade 1 and 2 in three municipalities were invited to a questionnaire survey, 97% participated (n = 3430). They were followed annually until age 19, and thereafter at age 28 years. In this study, participants at ages 8 y, 12 y, 19 y and 28 y (n = 2017) were included. Asthma was categorized into childhood onset (up to age 12 y) and adolescent onset (from 12 to 19 y). Data for assessment of socioeconomic status was collected at 28 y and included educational level, occupation, and occupational exposure to gas, dust and/or fumes (GDF).

RESULTS

Childhood onset asthma was associated with having compulsory school as the highest educational level at age 28 y, also after adjustment for sex, smoking and BMI at age 19 y and socioeconomic factors in childhood (OR 4.84 95%CI 2.01-11.65), and the pattern was the same among men and women. However, we found no significant associations between asthma in childhood or adolescence and socioeconomic groups, occupational groups or occupational exposure to GDF at age 28 y.

CONCLUSIONS

Even though asthma in high-income countries, such as Sweden, is well recognised and treated, this study highlight that childhood onset asthma may have a negative long-term effect with regard to educational level in young adulthood.

Mental Well-being and General Health in Adolescents with Asthma: The Prevention and Incidence of Asthma and Mite Allergy Birth Cohort Study

OBJECTIVES

To assess whether adolescents with asthma experience a lower mental well-being and lower general health than their peers without asthma.

STUDY DESIGN

Data from the Prevention and Incidence of Asthma and Mite Allergy study were used. At the ages of 11, 14, 17, and 20 years, 2651, 2522, 2094, and 2206 participants, respectively, completed questionnaires. Their parents completed questionnaires at the ages of 11 (n = 2660), 14 (n = 2338), and 17 years (n = 1872). Asthma was defined according to the Mechanisms of the Development of Allergy criteria. Mental well-being was measured using the Mental Health Index-5 and was reported by the adolescents. General health, measured on a 4-point Likert scale, was reported by the adolescents and their parents. We estimated associations of asthma with mental well-being and perceived general health using generalized estimating equations.

RESULTS

At ages 11, 14, 17, and 20 years, 6.7%, 6.9%, 5.0%, and 6.6%, respectively, of the adolescents had asthma. Adolescents with asthma did not score differently on the Mental Health Index than their peers without asthma. Adolescents with asthma were less likely to experience good or excellent health than their peers without asthma (aOR, 0.37; 95% CI, 0.26-0.51 for intermittent asthma and 0.33; 95% CI, 0.25-0.41 for persistent asthma). These results remain similar across the different ages.

CONCLUSIONS

The mental well-being of adolescents with asthma is similar to that of their peers without asthma, although adolescents with asthma are less likely to perceive a good or excellent general health.

Functional abdominal pain disorders and asthma: two disorders, but similar pathophysiology?

INTRODUCTION

Functional abdominal pain disorders (FAPDs) and asthma are common ailments affecting both children and adults worldwide. Multiple studies have demonstrated an association between these two disorders. However, the exact reason for this observed association is not apparent.

AREAS COVERED

The current review has explored available literature and outlined multiple underlying pathophysiological mechanisms, common to both asthma and FAPDs, as possible reasons for this association.

EXPERT OPINION

Smooth muscle dysfunction, hypersensitivity and hyper-responsiveness, mucosal inflammation, and barrier dysfunction involving gastrointestinal and respiratory tracts are the main underlying pathophysiological mechanisms described for the generation of symptoms in FAPDs and asthma. In addition, alterations in neuroendocrine regulatory functions, immunological dysfunction, and microbial dysbiosis have been described in both disorders. We believe that the pathophysiological processes that were explored in this article would be able to expand the mechanisms of the association. The in-depth knowledge is needed to be converted to therapeutic and preventive strategies to improve the quality of care of children suffering from FAPDs and asthma.

Does underweight amplify the relationship between short-term particulate matter exposure and blood pressure in children and adolescents: a large cross-sectional study in a metropolis of China

Overweight/obesity modified the effects of ambient particulate matter (PM) exposure on blood pressure (BP). This study aims to assess whether interaction of underweight and short-term PM exposure on BP exists in Chinese children. A cross-sectional analysis including 144,513 children aged 6 to 17 years in 2016 Health Promotion Program for Children and Adolescents of Suzhou, China, was performed. Daily concentrations of inhalable PM (PM₁₀) and fine PM (PM_2.5) were extracted from air monitoring stations close to students' schools. We applied generalized linear mixed-effects models to estimate the interactions. Estimated changes (95% confidence intervals (CIs)) of systolic BP (SBP), diastolic BP (DBP), and odds ratios (ORs) (95% CIs) for prevalence of HBP were calculated. Significant interactions between PM and underweight on BP and prevalence of high BP (HBP) were observed. For example, at lag 6, the ORs (95% CIs) for HBP by each 10 μg/m³ changes of PM_2.5 were 1.066 (1.039, 1.093) and 1.036 (1.028, 1.043) among underweight and normal weight subjects, respectively; these values for PM₁₀ were 1.048 (1.031, 1.065) and 1.025 (1.021, 1.030). At lag 5, the increases of SBP for PM_2.5 were 0.32 (95% CI 0.22, 0.43) mmHg and 0.23 (95% CI 0.29, 0.26) mmHg, while changes of DBP were 0.27 (95% CI 0.18, 0.35) mmHg and 0.19 (95% CI 0.16, 0.21) mmHg among underweight and normal weight subjects, respectively. Stratified analyses demonstrated that these interactions were only obtained in males. Effects of short-term PM exposure on BP and prevalence of HBP are enhanced in underweight children and adolescents.

The Dynamic Relationship Between Asthma and Obesity in Schoolchildren

Asthma and obesity are among the most prevalent chronic health conditions in children. Although there has been compelling evidence of co-occurrence of asthma and obesity, it is uncertain whether asthma contributes to the development of obesity or obesity contributes to the onset of asthma or both. In this study, we used a joint transition modeling approach with cross-lagged structure to understand how asthma and obesity influence each other dynamically over time. Subjects for this study included 5,193 kindergarten and first-grade students enrolled from 13 communities in 2002-2003 in the Southern California Children's Health Study, with up to 10 years of follow-up. We found that nonobese children with diagnosed asthma at a study visit were at 37% higher odds of becoming obese by the next annual visit compared with children without asthma (odds ratio = 1.38; 95% credible interval: 1.12, 1.71). However, the presence of obesity at the current visit was not statistically significantly associated with asthma onset in the next visit (odds ratio = 1.25; 95% credible interval: 0.94, 1.62). In conclusion, childhood asthma appears to drive an increase in the onset of obesity among schoolchildren, while the onset of obesity does not necessarily imply the future onset of asthma, at least in the short term.

Obesity and childhood asthma

PURPOSE OF REVIEW

Asthma is a common chronic disease of the airways characterized by recurrent respiratory symptoms, bronchoreactivity, and airway inflammation. The high toll on quality of life has led to sustained efforts to understand the factors leading to asthma inception and poor disease control. Obesity is another increasingly common pediatric disease, which appears to increase the risk for incident asthma and worsened disease severity. Currently, our understanding of how obesity affects asthma risk and affects its phenotypic characteristics remains incomplete. The current review describes our current understanding of the epidemiology, clinical characteristics, and management considerations of obesity-related asthma in children.

RECENT FINDINGS

The epidemiologic relationship between obesity in children and incident asthma remains confusing despite numerous longitudinal cohort studies, and appears to be influenced by early life exposures, patterns of somatic growth and underlying familial risks of allergic disease. Children with comorbid obesity and asthma demonstrate diverse phenotypic characteristics which are still becoming clear.

SUMMARY

Like any child with asthma, a child with comorbid obesity requires an individualized approach adhering to current best-practice guidelines and an understanding of how obesity and asthma may interact.

Short-term effects of ambient particulate matter on blood pressure among children and adolescents:A cross-sectional study in a city of Yangtze River delta, China

Several studies have demonstrated associations between short-term exposure to particulate matter (PM) and blood pressure (BP) among various adults groups, but evidence in children and adolescents is still rare. In 2016, a cross-sectional survey was conducted among 194 104 participants aged 6-17 years in Suzhou, China. Daily concentrations of particulate matters with an aerodynamic diameter of ≤10 μg/m³ (PM₁₀) and aerodynamic diameter ≤2.5 μg/m³ (PM_2.5) on 0-6 days preceding BP examination were collected from nearby air monitoring stations. Using generalized linear mixed-effects models, short-term effects of PM on personal BP were estimated. A 10 μg/m³ increment in the 0-6 day mean of PM_2.5 was significantly associated with elevation of 0.20 mmHg [95% confidence interval (95% CI) 0.16-0.23] in systolic BP (SBP), 0.49 mmHg (95% CI 0.45-0.53) in diastolic BP (DBP), respectively. Similarly, 0.14 mmHg (95% CI 0.12-0.16) higher SBP and 0.32 mmHg (95% CI 0.30-0.34) higher DBP were found for each 10 μg/m³ increase in 0-6 day mean of PM₁₀. More apparent associations were observed in females than in males. Odds ratio (95%CI) of for PM_2.5 exposure at 0-6 d mean was 1.06 (1.03-1.08) in females, while it was 1.01 (0.99-1.03) in males. Participants with young ages, underweight and obesity were also associated with increased susceptibility to PM-induced BP effects. Short-term exposure in PM was significantly associated with elevated BP in children, indicating a need to control PM levels and protect children from PM exposure in China.

Asthma control and acute healthcare visits among young adults with asthma-A population-based study

AIMS

To study asthma control and acute healthcare visits among young adults with asthma.

BACKGROUND

Despite the access to effective treatment and nursing interventions, poor asthma control is still common among individuals with asthma. However, studies describing clinical characteristics among young adults with asthma are rare.

DESIGN

A population-based cohort study.

METHODS

In 2015, as a part of the OLIN paediatric cohort I (recruited in 1996 at age 7-8 years), N = 2,291 young adults (27-28 years) completed a postal questionnaire survey including questions on asthma and respiratory symptoms. Of these, N = 280 (12%) were identified as having current asthma and were further studied.

RESULTS

Of those with current asthma, women reported respiratory symptoms and smoking to a greater extent than men. Approximately one-fourth had uncontrolled asthma and acute healthcare visits due to asthma was reported by 15% of women and 8% of men. Uncontrolled asthma was associated with smoking, lower educational level, use of reliever treatment most days, and acute healthcare visits. Acute healthcare visits due to asthma were associated with periodic use of regular controller treatment also after adjustment for uncontrolled asthma.

CONCLUSION

The result indicate poor adherence to asthma treatment which may lead to decreased asthma control and acute healthcare visits.

IMPACT

Most young adults with asthma are diagnosed and treated in primary care, ideally in a team with a nurse. The main findings highlight the need for evidenced-based nursing interventions, contributing to a more efficient asthma management in primary care.

Association between overweight or obesity and the risk for childhood asthma and wheeze: An updated meta-analysis on 18 articles and 73 252 children

BACKGROUND

Overweight or obesity is increasingly recognized as a possible risk factor for childhood asthma.

OBJECTIVES

We aimed to meta-analyse the association between overweight or obesity and the risk for childhood asthma and wheeze and meanwhile explore potential causes of between-study heterogeneity.

METHODS

Literature search, study selection, and data extraction were performed independently and in duplicate. Data were analysed by STATA software.

RESULTS

Eighteen articles and 73 252 children were analysed. In overall analyses, there was a significant association between overweight or obesity and the risk for childhood asthma (odds ratio [OR] = 1.30; 95% confidence interval [CI], 1.23-1.39; P < 0.001) and wheeze (OR = 1.90; 95% CI, 1.38-2.63; P < 0.001), with none/marginal publication bias as revealed by the Egger test (P = 0.938/0.038), respectively. Subgroup analyses showed that children with obesity (OR = 1.40; 95% CI, 1.29-1.52) were more likely to have asthma than children with overweight (OR = 1.22; 95% CI, 1.14-1.31), and in children with overweight or obesity, girls (OR = 1.34; 95% CI, 1.16-1.56) were more likely to have asthma than boys (OR = 1.27; 95% CI, 1.15-1.40).

CONCLUSIONS

Our findings indicate that overweight or obesity is a significant risk factor for childhood asthma and wheeze and in children with overweight or obesity, the risk is more evident in girls than in boys.

Increased prevalence of exercise-induced airway symptoms - A five-year follow-up from adolescence to young adulthood

BACKGROUND

Exercise-induced airway symptoms are common in adolescents. Little is known about the development of symptoms from adolescence to early adulthood. Therefore, we studied the prevalence, incidence, and remission of exercise-induced airway symptoms (including wheeze, cough, chest and throat tightness, hoarseness, and stridor) in adolescents, over a five-year period.

METHODS

In 2011, all adolescents aged 12-13 years in Uppsala (n = 3 838) were invited to answer a questionnaire on exercise-induced airway symptoms. All responding adolescents (n = 2 309) were invited to answer the same questionnaire again after five years. In total, 1 002 adolescents responded (43.4%).

RESULTS

The prevalence of exercise-induced airway symptoms increased from 25% at baseline to 49% at follow-up (p < 0.001). More females than males reported symptoms at both time points. The incidence of airway symptoms was 42.2%, with no sex differences. More males than females reported symptom remission (20.2 vs. 10.7%, p < 0.001). Females reported a higher asthma prevalence at follow-up than at baseline (7.6 vs. 15.2%), while males did not (10.9 vs. 8.0%), leading to a sex difference in prevalence at follow-up (p < 0.001). Smoking and baseline respiratory symptoms were associated with an increased risk of reporting symptoms at follow-up.

CONCLUSIONS

A twofold increase in the prevalence of exercise-induced airway symptoms over a five-year period was found in this cohort. Females were more likely to report symptoms at both time points. Knowledge of these age-related changes in symptoms and their association to female gender is useful for future studies and healthcare providers.

Being Overweight or Obese and the Development of Asthma

OBJECTIVES

Adult obesity is linked to asthma cases and is estimated to lead to 250 000 new cases yearly. Similar incidence and attributable risk (AR) estimates have not been developed for children. We sought to describe the relationship between overweight and obesity and incident asthma in childhood and quantify AR statistics in the United States for overweight and obesity on pediatric asthma.

METHODS

The PEDSnet clinical data research network was used to conduct a retrospective cohort study (January 2009-December 2015) to compare asthma incidence among overweight and/or obese versus healthy weight 2- to 17-year-old children. Asthma incidence was defined as ≥2 encounters with a diagnosis of asthma and ≥1 asthma controller prescription. Stricter diagnostic criteria involved confirmation by spirometry. We used multivariable Poisson regression analyses to estimate incident asthma rates and risk ratios and accepted formulas for ARs.

RESULTS

Data from 507 496 children and 19 581 972 encounters were included. The mean participant observation period was 4 years. The adjusted risk for incident asthma was increased among children who were overweight (relative risk [RR]: 1.17; 95% confidence interval [CI]: 1.10-1.25) and obese (RR: 1.26; 95% CI: 1.18-1.34). The adjusted risk for spirometry-confirmed asthma was increased among children with obesity (RR: 1.29; 95% CI: 1.16-1.42). An estimated 23% to 27% of new asthma cases in children with obesity is directly attributable to obesity. In the absence of overweight and obesity, 10% of all cases of asthma would be avoided.

CONCLUSIONS

Obesity is a major preventable risk factor for pediatric asthma.

BMI at school age and incident asthma admissions in early adulthood: a prospective study of 310,211 children

Background

Excess body weight in adulthood is associated with risk for asthma admission (AA). Our aim was to investigate if this association also applies to the relation between body mass index (BMI) in childhood and AAs in early adulthood (age 20–45 years).

Methods

This was a prospective study of 310,211 schoolchildren (born 1930–1989) from the Copenhagen School Health Records Register. Height and weight were measured annually, and generated BMI z-scores were categorized as low (lower quartile), normal (interquartile) and high (upper quartile). Associations between BMI at ages 7–13 and AA were estimated by Cox regressions, and presented as hazard ratios (HRs) and 95% confidence intervals (CI). Main outcome was incident hospital AAs (extracted from the Danish National Patient Register) in early adulthood.

Results

During 4,708,607 person-years of follow-up, 1,813 incident AAs were observed. Nonlinear associations were detected between childhood BMI and AAs. The risk of AA increased for females in the highest BMI category in childhood, with the highest HR of 1.3 (95% CI 1.16–1.55) at the age of 13 years. By contrast, males in the low BMI category had a higher risk of AA in early adulthood, with the highest HR of 1.24 (95% CI 1.03–1.51) at the age of 12 years. Females with an increase in BMI between ages 7 and 13 years had an increased risk of AA compared with females with stable BMI (HR 1.28, 95% CI 1.10–1.50).

Conclusion

The association between childhood BMI and AA in early adulthood is non-linear. High BMI increases the risk of AA in females, whereas low BMI increases the risk in males.

The sex-shift in single disease and multimorbid asthma and rhinitis during puberty - a study by MeDALL

BACKGROUND

Cross-sectional studies suggested that allergy prevalence in childhood is higher in boys compared to girls, but it remains unclear whether this inequality changes after puberty. We examined the sex-specific prevalence of asthma and rhinitis as single and as multimorbid diseases before and after puberty onset in longitudinal cohort data.

METHODS

In six European population-based birth cohorts of MeDALL, we assessed the outcomes: current rhinitis, current asthma, current allergic multimorbidity (ie, concurrent asthma and rhinitis), puberty status and allergic sensitization by specific serum antibodies (immunoglobulin E) against aero-allergens. With generalized estimating equations, we analysed the effects of sex, age, puberty (yes/no) and possible confounders on the prevalence of asthma and rhinitis, and allergic multimorbidity in each cohort separately and performed individual participant data meta-analysis.

FINDINGS

We included data from 19 013 participants from birth to age 14-20 years. Current rhinitis only affected girls less often than boys before and after puberty onset: adjusted odds ratio for females vs males 0.79 (95%-confidence interval 0.73-0.86) and 0.86 (0.79-0.94), respectively (sex-puberty interaction P = .089). Similarly, for current asthma only, females were less often affected than boys both before and after puberty onset: 0.71, 0.63-0.81 and 0.81, 0.64-1.02, respectively (sex-puberty interaction P = .327). The prevalence of allergic multimorbidity showed the strongest sex effect before puberty onset (female-male-OR 0.55, 0.46-0.64) and a considerable shift towards a sex-balanced prevalence after puberty onset (0.89, 0.74-1.04); sex-puberty interaction: P < .001.

INTERPRETATION

The male predominance in prevalence before puberty and the "sex-shift" towards females after puberty onset were strongest in multimorbid patients who had asthma and rhinitis concurrently.

Adolescent girls with asthma have worse asthma control and health-related quality of life than boys-A population based study

BACKGROUND

Population-based studies investigating health-related quality of life (HRQoL) among asthmatic adolescents are rare. Further, among subjects with asthma, HRQoL may be affected by asthma control and severity.

AIM

To investigate HRQoL in relation to asthma control and asthma severity among adolescents.

METHOD

As a part of the population-based OLIN pediatric study, 266 adolescents with current asthma (14-15 yr) were identified. N = 247 completed the DISABKIDS HRQoL asthma module, including the domains impact and worry. The Asthma Control Test (ACT) was used and a disease severity score was calculated based on symptoms and medicine use.

RESULTS

The prevalence of current asthma was 11%. Well-controlled asthma was reported by 15% of the adolescents, and 53% had partly controlled asthma. The prevalence of uncontrolled asthma was significantly higher among girls than boys (38% vs 25%), and girls also reported lower HRQoL scores. There was a fairly strong correlation between the ACT and DISABKIDS scores. Independent risk factors for low HRQoL impact (a score <67) were female sex (OR 4.66, 95%CI 1.82-9.54) and decreased ACT scores (1.38, 1.18-1.62). Risk factors for low HRQoL worry (a score <70) were female sex (3.33, 1.41-7.86), decreased ACT scores (1.35, 1.16-1.57), severe asthma (6.23, 1.46-16.50), and having current eczema (2.68, 1.00-7.24).

CONCLUSION

Only a minority of the asthmatic adolescents reported well-controlled asthma, and poor asthma control and female sex were risk factors for low HRQoL. Our results demonstrate that evaluation of asthma control is of great importance for asthma management.

Population-based study shows that teenage girls with asthma had impaired health-related quality of life

AIM

This study examined the health-related quality of life (HRQoL) of teenagers with and without asthma, including the impact of their sex, allergic conditions, smoking, living conditions and physical activity.

METHODS

The Obstructive Lung Disease in Northern Sweden (OLIN) studies recruited a cohort of schoolchildren in 2006. The parents of all children aged seven to eight years in three municipalities were invited to complete a questionnaire and 2585 (96%) participated. The cohort was followed up at the ages of 11-12 years and 14-15 years with high participation rates. At 14-15 years, the HRQoL questionnaire KIDSCREEN-10 and Asthma Control Test were added.

RESULTS

Girls with current asthma at 14-15 years had a lower mean HRQoL score than girls without asthma (46.4 versus 49.3, p < 0.001), but this was not seen among boys (53.8 versus 52.8, p = 0.373). Poor HRQoL was related to current asthma, uncontrolled asthma and teenage onset of asthma. It was also related to eczema, living in a single-parent household, maternal smoking, daily smoking and inversely related to physical activity.

CONCLUSION

Teenage girls with asthma had lower HRQoL than girls without asthma. Possible interventions to improve HRQoL among teenagers with asthma were identified as follows: increasing asthma control, preventing smoking and promoting physical activity.

Is impaired glucose metabolism the missing piece in the obesity-asthma puzzle?

Obesity is a major risk factor for several conditions including atherosclerotic disease, metabolic syndrome, and upper airway dysfunction. However, the purported link between obesity and asthma has remained more difficult to define, in part due to limitations in past epidemiologic studies and the inherent challenge in accurately defining asthma in children. It is possible that obesity leads to asthma only in the presence of a mediating variable such as an obesity-related conditions such as esophageal reflux or insulin resistance. The article by Karampatakis and colleagues in this week's edition of the journal is important because it addresses the hypothesis that altered glucose metabolism/insulin resistance associates with bronchial hyperresponsiveness (BHR), a central and objectively measured marker of asthma. They studied pre-pubertal children with and without asthma with a range of body mass indices and found for the first time in pre-pubertal asthmatic children that both insulin resistance and impaired glucose tolerance were more closely related to BHR than was obesity. Their work opens the way for directed mechanistic study of the effects of impaired glucose metabolism on airway development during childhood and airway responsiveness, and for the study of insulin sensitizing therapies in children to prevent lower airway disease. Pediatr Pulmonol. 2017;52:147-150. © 2016 Wiley Periodicals, Inc.

Early smoke exposure is associated with asthma and lung function deficits in adolescents

OBJECTIVE

Early life tobacco smoke exposure may influence asthma, lung function and lung function growth into adolescence. We aimed to determine the associations between perinatal smoke exposure and asthma and lung function up to 18 years of age.

METHODS

We prospectively recorded perinatal parental smoking and measured respiratory outcomes at 12 and 18 years in the Melbourne Atopy Cohort Study (MACS), a longitudinal birth cohort. Multiple logistic regression was used to analyse the associations between perinatal smoke exposure and asthma at 12 (n = 370) and 18 years (n = 411). Multiple linear regression was used to investigate the relationship between perinatal smoking and: lung function (12 and 18 years) and lung function growth (between 12 and 18 years).

RESULTS

At 18 years, girls exposed to parental smoking during the perinatal period had increased odds of asthma (OR: 3.45, 95%CI: 1.36, 8.77), reduced pre-bronchodilator Forced expiratory volume in one-second (FEV₁) (-272 ml/s; -438, -107); FEV₁/ forced vital capacity (FVC) (-0.038; -0.065, -0.010); mid expiratory flow (MEF_25-75) (-430 ml/s; -798, -61), and reduced post-bronchodilator FEV₁/FVC (-0.028, -0.053, -0.004). No associations were found for boys (pre-bronchodilator FEV₁ 26ml/s; -202, 255; FEV₁/FVC 0.018; -0.013, 0.049).

CONCLUSIONS

Perinatal smoke may affect risk of asthma, reduce lung function and lung function growth in adolescence. Girls appear to be more susceptible than boys.

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

OBJECTIVE

To evaluate the relationship of fitness and obesity on asthma risk in adolescent girls and boys.

STUDY DESIGN

A cross-sectional assessment of participants 12-19 years of age was conducted by the use of data from the 1999-2004 National Health and Nutrition Examination Survey. Participants completed cardiorespiratory fitness testing, body composition measurements, and respiratory questionnaires.

RESULTS

A total of 4828 participants were included. Overweight/obesity was associated with increased odds of history of asthma (aOR 1.63, 95% CI 1.16-2.30), current asthma (aOR 1.73, 95% CI 1.13, 2.64), and wheezing (aOR 1.40, 95% CI 1.03-1.91) in girls. Overweight/obesity also was associated with increased odds of asthma attacks (aOR 2.67, 95% CI 1.56-4.65) and wheezing related to exercise (aOR 1.60, 95% CI 1.07-2.38) in girls. High fitness was associated with lower odds of asthma-related visits to the emergency department (aOR 0.24, 95% CI 0.07-0.89), wheezing-related medical visits (aOR 0.31, 95% CI 0.13-0.75), wheezing-related missed days (aOR 0.14, 95% CI 0.06-0.33), and wheezing related to exercise (aOR 0.43, 95% CI 0.24-0.76) in boys.

CONCLUSION

Overweight/obesity is associated with increased asthma prevalence and morbidity in girls but not in boys, independent of fitness. High fitness is associated with decreased rates of asthma morbidity in boys but not in girls, independent of weight status. Obesity and fitness may each influence asthma onset and severity in different ways for girls compared with boys.

Need of education for dry powder inhaler storage and retention - a patient-reported survey

BACKGROUND

Dry powder inhalers (DPIs) are the most commonly used devices in asthma treatment in the Nordic countries. As new DPIs become available, patients are likely to be exposed to more than one type of device, with variable optimal handling. The aim was to examine real life storage and retention of multidose DPIs in patients with asthma.

METHODS

This patient-reported survey on real life storage and retention of DPIs included asthma patients using multidose DPIs. Basic patient characteristics, information on inhaler use and storage, check of expiry date, and concurrent inhaler use was examined using an on line questionnaire.

RESULTS

A total of 738 patients were included with a median age of 41 years, out of which 83 % were women. Sixty-three per cent reported storage conditions pre-defined as risk locations for their maintenance inhaler and 38 % of the responding patients had more than one maintenance inhaler in use at the same time. Two thirds of the study population checked inhaler expiry date less than monthly or not at all. Use after expiry date was frequently reported. Two thirds of the patients had not received information on DPI storage, either from their doctor and/or nurse or at the pharmacy.

CONCLUSIONS

This patient reported survey indicates that two thirds of the patients store their inhaler devices in suboptimal conditions, and only a minority had received instruction regarding inhaler handling. Non awareness of inhalers' expiry dates and use of more than one maintenance inhaler simultaneously was common. As inhaler mishandling may impact device functionality, improved communication and patient education is needed.

Obesity, Asthma, and Exercise in Child and Adolescent Health

Obesity increases the risk of asthma throughout life but the underlying mechanisms linking these all too common threats to child health are poorly understood. Acute bouts of exercise, aerobic fitness, and levels of physical activity clearly play a role in the pathogenesis and/or management of both childhood obesity and asthma. Moreover, both obesity and physical inactivity are associated with asthma symptomatology and response to therapy (a particularly challenging feature of obesity-related asthma). In this article, we review current understandings of the link between physical activity, aerobic fitness and the asthma-obesity link in children and adolescents (e.g., the impact of chronic low-grade inflammation, lung mechanics, and direct effects of metabolic health on the lung). Gaps in our knowledge regarding the physiological mechanisms linking asthma, obesity and exercise are often compounded by imprecise estimations of adiposity and challenges of assessing aerobic fitness in children. Addressing these gaps could lead to practical interventions and clinical approaches that could mitigate the profound health care crisis of the increasing comorbidity of asthma, physical inactivity, and obesity in children.

Racial disparity in the association between body mass index and self-reported asthma in children: a population-based study

OBJECTIVE

To examine the racial disparity in the association between obesity and asthma in US children and adolescents.

METHODS

This study was based on a nationally representative, random-digit-dial sample of US households with children less than 18 years of age from the National Survey of Children's Health in 2011/2012 and 2007. The study sample included 88,668 children ages 10-17 with data on body mass index (BMI), parental reporting of asthma diagnosis, and potential confounders. Multiple logistic regression analysis was performed to estimate the crude and adjusted odds ratios stratified by child race/ethnicity.

RESULTS

The prevalence of overweight was 15.2% and obesity was 14.1%. Self-reported asthma diagnosis was 16.7% in our study sample. Obese children were 51% more likely to have asthma compared to normal weight children after controlling for child's sex, child age, socioeconomic status, environmental tobacco smoke (ETS), and neighborhood conditions. Our study also shows that the strength of this association varied by race/ethnicity after stratification. Being male, being non-Hispanic Black or Multi-racial, below the Federal Poverty Level, ETS and having detracting neighborhood elements were also significantly associated with higher odds of having a self-reported asthma diagnosis.

CONCLUSION

We observed a racial difference in the association between BMI and asthma in US children. Our findings have significant public health implications and may help public health practitioners to target children and adolescents at higher risk of prevention and intervention efforts.

Childhood body mass index and wheezing disorders: a systematic review and meta-analysis

BACKGROUND

It has been claimed that overweight/obesity, childhood asthma and wheezing disorders are associated, although the results of observational studies have remained inconsistent. We conducted a systematic review and meta-analysis to investigate this.

METHODS

An online search of published papers linking childhood asthma and wheezing with overweight/obesity up to May 2014 using EMBASE and MEDLINE medical research databases was carried out. Summary odds ratios (OR) were estimated using random-effects models. Subgroup meta-analyses were performed to assess the robustness of risk associations and between-study heterogeneity.

RESULTS

A total of 38 studies comprising 1,411,335 participants were included in our meta-analysis. The summary ORs of underweight (<5th percentile), overweight (>85th to <95th percentile) and obesity (≥ 95 th percentile) were 0.85 (95% CI: 0.75 to 0.97; p = 0.02), 1.23 (95% CI: 1.17 to 1.29; p < 0.001) and 1.46 (95% CI: 1.36 to 1.57, p < 0.001), respectively. Heterogeneity was significant and substantial in all three weight categories, and not accounted for by pre-defined study characteristics.

CONCLUSION

Our results suggest that underweight is associated with a reduced risk of childhood asthma, and overweight and obesity are associated with an increased risk of childhood asthma. Although our findings assert that overweight/obesity and childhood asthma are associated, the causal pathway and temporal aspects of this relationship remain unanswered and deserve further epidemiological investigation.

Body mass index and the incidence of asthma in children

PURPOSE OF REVIEW

When evaluating the causal link between obesity and the development of asthma in children, prospective cohort studies are essential. The results of the most recently published birth cohort studies from Sweden, Germany, Brazil, Belarus, and California, USA, as well as from a joint analysis of eight European birth cohorts of the Global Allergy and Asthma European Network are evaluated. Moreover, the results of two meta-analyses are presented.

RECENT FINDINGS

Most recent prospective cohort studies found a dose-response association between overweight or obesity and asthma. The evidence of effect modification by sex, ethnicity, and age was inconsistent. Both meta-analyses also showed that overweight children were at an increased risk of incident asthma compared with nonoverweight children and that the relationship was further elevated for obesity.

SUMMARY

Prospective cohort studies and two recently published meta-analyses found an association between overweight (and especially obesity) and asthma in the appropriate temporal sequence and in a dose-response manner. Children with a pronounced weight gain slope in early life were particularly at risk for asthma within the first 6 years of life. The gain in BMI over time during infancy may be an even more important predictor for asthma in childhood than excess weight at any specific age.

Oral contraceptives modify the effect of GATA3 polymorphisms on the risk of asthma at the age of 18 years via DNA methylation

BACKGROUND

The prevalence of asthma in girls increases after puberty. Previous studies have detected associations between sex hormones and asthma, as well as between sex hormones and T helper 2 (Th2) asthma-typical immune responses. Therefore, we hypothesized that exogenous or endogenous sex hormone exposure (represented by oral contraceptive pill (OCP) use and early menarche, respectively) are associated with DNA methylation (DNA-M) of the Th2 transcription factor gene, GATA3, in turn affecting the risk of asthma in girls, possibly in interaction with genetic variants. Blood samples were collected from 245 female participants aged 18 years randomly selected for methylation analysis from the Isle of Wight birth cohort, UK. Information on use of OCPs, age at menarche, and concurrent asthma were assessed by questionnaire. Genome-wide DNA-M was determined using the Illumina Infinium HumanMethylation450 beadchip. In a first stage, we tested the interaction between sex hormone exposure and genetic variants on DNA-M of specific cytosine-phosphate-guanine (CpG) sites. In a second stage, we determined whether these CpG sites interact with genetic variants in GATA3 to explain the risk of asthma.

RESULTS

Interactions between OCP use and seven single nucleotide polymorphisms (SNPs) of GATA3 were analyzed for 14 CpG sites (stage 1). The interaction between OCP use and SNP rs1269486 was found to be associated with the methylation level of cg17124583 (P = 0.002, false discovery rate (FDR) adjusted P = 0.04). DNA-M of this same CpG site was also influenced by the interaction between age at menarche and rs1269486 (P = 0.0017). In stage 2, we found that cg17124583 modified the association of SNP rs422628 with asthma risk at the age of 18 years (P = 0.006, FDR adjusted P = 0.04). Subjects with genotype AG showed an increase in average risk ratio (RR) from 0.31 (95% CI: 0.10 to 0.8) to 11.65 (95% CI: 1.71 to 79.5) when methylation level increased from 0.02 to 0.12, relative to genotype AA.

CONCLUSION

A two-stage model consisting of genetic variants in the GATA3 gene, OCP use, age at menarche, and DNA-M may explain how sex hormones in women can increase the asthma prevalence after puberty.

Does gender affect asthma control in adult asthmatics?

Several studies have shown gender differences in prevalence of asthma but there is little information about asthma control. In this study, we aimed to evaluate the effect of gender on asthma control in adult asthmatics. Medical records of 242 patients older than 18 years of age who regularly visited the allergy unit were evaluated. Standardized asthma questionnaires like the asthma control test (ACT) were performed. ACT scores, clinical characteristics, and demographic data such as smoking status, education, duration and severity of asthma, atopic status, family history of asthma, analgesic hypersensitivity, number of emergency visits, and hospitalization in the previous year were compared based on gender. In this study, 77.3% of the patients were female. Mean age, body mass index, and duration of asthma were 39.0 ± 0.7, 27.3 ± 0.3, and 6.6 ± 0.4 years, respectively. Of the total, 14.9% of the patients were smokers. Also, 55.8% of them were graduated from middle school, 22.7% from high school, and 14% from university. Atopy rate was 57%. Analgesic hypersensitivity was found in 18.6% of them. There was 30.2% family history of asthma. The asthma severity was mild in 45.5%, moderate in 40.9%, and severe in 13.6% of the patients. One-third of the patients were admitted to emergency room; 1/10th were hospitalized due to asthma in the previous year. ACT scores indicated complete control in 67.8%, partial control in 17.8%, and uncontrolled asthma in 14.5%. Comparing the results of males with females having asthma, there was no statistically significant difference between the two gender according to ACT scores and clinical characteristics. Finally, the results conclude that there was no effect of gender on asthma control assessed with standardized questionnaire in adult asthmatics.

Epidemiologic methods of assessing asthma and wheezing episodes in longitudinal studies: measures of change and stability

Background

In settings in which diseases wax and wane, there is a need to measure disease dynamics in longitudinal studies. Traditional measures of disease occurrence (eg, cumulative incidence) do not address change or stability or are limited to stable cohorts (eg, incidence) and may thus lead to erroneous conclusions. To illustrate how different measures can be used to detect disease dynamics, we investigated sex differences in the occurrence of asthma and wheezing, using a population-based study cohort that covered the first 18 years of life.

Methods

In the Isle of Wight birth cohort (n = 1456), prevalence, incidence, cumulative incidence, positive and negative transitions, and remission were determined at ages 1 or 2, 4, 10, and 18 years. Latent transition analysis was used to simultaneously identify classes of asthma and wheezing (related phenotypes) and characterize transition probabilities over time. Trajectory analysis was used to characterize the natural history of asthma and wheezing.

Results

Regarding time-specific changes, positive and negative transition probabilities were more informative than other measures of associations because they revealed a sex switchover in asthma prevalence (P < 0.05). Transition probabilities were able to identify the origin of a sex-specific dynamic; in particular, prior wheezing transitioned to asthma at age 18 years among girls but not among boys. In comparison with latent transition analysis, trajectory analysis did not directly identify a switchover in prevalence among boys and girls.

Conclusions

In longitudinal analyses, transition analyses that impose minimal restrictions on data are needed in order to produce appropriate information on disease dynamics.

Childhood body mass index and subsequent physician-diagnosed asthma: a systematic review and meta-analysis of prospective cohort studies

Background

Childhood asthma and obesity prevalence have increased in recent years suggesting a potential association. However, the direction of any association is poorly understood and the potential causal-relationship is unknown.

Methods

We examined the association between overweight/obesity, defined by body mass index (BMI) <18 years of age, and subsequent physician-diagnosed incident asthma at least one year after BMI assessment. We sought to explore potential effect modification by sex. PubMed and Embase were searched using keywords and restricted to subjects aged 0–18 years. There were no date or language restrictions. From each study we extracted: authors, publication date, location, overweight/obesity definitions, asthma definitions, number of participants, recruitment duration, description of cohort, follow-up time, adjusted effect estimates (with 95% CI) and estimates of subgroup analysis.

Results

Six prospective cohort studies which focused on children <18 years of age met criteria for inclusion. The combined risk ratio (RR) of overweight was associated with asthma (RR = 1.35; 95% CI = 1.15, 1.58). In boys, the combined RR of overweight on asthma was significant (RR = 1.41; 95% CI = 1.05, 1.88). For girls, when BMI was defined by Z-score, the combined RR of overweight on asthma was also significant (RR = 1.19; 95% CI = 1.06, 1.34). The combined risk ratio (RR) of obesity was associated with asthma in both boys and girls (RR = 1.50; 95% CI = 1.22, 1.83), in boys only (RR = 1.40; 95% CI = 1.01, 1.93) and in girls only (RR = 1.53; 95% CI = 1.09, 2.14).

Conclusions

Overweight and, especially, obese children are at increased risk of subsequent physician diagnosed asthma in comparison to normal weight children. Except for sex, no studies reported any other potential effect modifiers. The observed sex effects were inconsistent.

Asthma Heredity, Cord Blood IgE and Asthma-Related Symptoms and Medication in Adulthood: A Long-Term Follow-Up in a Swedish Birth Cohort

Cord blood IgE has previously been studied as a possible predictor of asthma and allergic diseases. Results from different studies have been contradictory, and most have focused on high-risk infants and early infancy. Few studies have followed their study population into adulthood. This study assessed whether cord blood IgE levels and a family history of asthma were associated with, and could predict, asthma medication and allergy-related respiratory symptoms in adults. A follow-up was carried out in a Swedish birth cohort comprising 1,701 consecutively born children. In all, 1,661 individuals could be linked to the Swedish Prescribed Drug Register and the Medical Birth Register, and 1,227 responded to a postal questionnaire. Cord blood IgE and family history of asthma were correlated with reported respiratory symptoms and dispensed asthma medication at 32-34 years. Elevated cord blood IgE was associated with a two- to threefold increased risk of pollen-induced respiratory symptoms and dispensed anti-inflammatory asthma medication. Similarly, a family history of asthma was associated with an increased risk of pollen-induced respiratory symptoms and anti-inflammatory medication. However, only 8% of the individuals with elevated cord blood IgE or a family history of asthma in infancy could be linked to current dispensation of anti-inflammatory asthma medication at follow-up. In all, 49 out of 60 individuals with dispensed anti-inflammatory asthma medication at 32-34 years of age had not been reported having asthma at previous check-ups of the cohort during childhood. Among those, only 5% with elevated cord blood IgE and 6% with a family history of asthma in infancy could be linked to current dispensation of anti-inflammatory asthma medication as adults. Elevated cord blood IgE and a positive family history of asthma were associated with reported respiratory symptoms and dispensed asthma medication in adulthood, but their predictive power was poor in this long-time follow-up.

Gender, airborne chemical monitoring, and physical work environment are related to indoor air symptoms among nonindustrial workers in the Klang Valley, Malaysia

Objectives:

The purpose of this study was to analyze the relationship of airborne chemicals and the physical work environment risk element on the indoor air symptoms of nonindustrial workers.

Design:

A cross-sectional study consisting of 200 office workers. A random selection of 200 buildings was analyzed for exposure and indoor air symptoms based on a pilot study in the Klang Valley, Malaysia.

Methods:

A set of modified published questionnaires by the Department of Occupational Safety and Health (DOSH), Malaysia and a previous study (MM040NA questionnaire) pertaining to indoor air symptoms was used in the evaluation process of the indoor air symptoms. Statistical analyses involving logistic regression and linear regression were used to determine the relationship between exposure and indoor air symptoms for use in the development of an indoor risk matrix.

Results:

The results indicate that some indoor air pollutants (carbon monoxide, formaldehyde, total volatile organic compound, and dust) are related to indoor air symptoms of men and women. Temperature and relative humidity showed a positive association with complaints related to the perceived indoor environmental condition (drafts and inconsistency of temperature). Men predominantly reported general symptoms when stratification of gender involved exposure to formaldehyde. Women reported high levels of complaints related to mucosal and general symptoms from exposure to the dust level indoors.

Conclusion:

Exposure to pollutants (total volatile organic compounds, carbon monoxide, and formaldehyde) and physical stressors (air temperature and relative humidity) influence reported symptoms of office workers. These parameters should be focused upon and graded as one of the important elements in the grading procedure when qualitatively evaluating the indoor environment.

Gender difference of childhood overweight and obesity in predicting the risk of incident asthma: a systematic review and meta-analysis

The aims of our meta-analysis were (i) to quantify the predictability of childhood overweight and obesity on the risk of incident asthma; and (ii) to evaluate the gender difference on this relationship. The selection criteria included prospective cohort paediatric studies which use age- and sex-specific body mass index (BMI) as a measure of childhood overweight and the primary outcome of incident asthma. A total of 1,027 studies were initially identified through online database searches, and finally 6 studies met the inclusion criteria. The combined result of reported relative risk from the 6 included studies revealed that overweight children conferred increased risks of incident asthma as compared with non-overweight children (relative risk, 1.19; 95% confidence interval [CI], 1.03-1.37). The relationship was further elevated for obesity vs. non-obesity (relative risk, 2.02; 95% CI, 1.16-3.50). A dose-responsiveness of elevated BMI on asthma incidence was observed (P for trend, 0.004). Obese boys had a significantly larger effect than obese girls (relative risk, boys: 2.47; 95% CI, 1.57-3.87; girls: 1.25; 95% CI, 0.51-3.03), with significant dose-dependent effect. Proposed mechanisms of gender difference could be through pulmonary mechanics, sleep disordered breathing and leptin. Further research might be needed to better understand the exact mechanism of gender difference on the obesity-asthma relationship.

Obesity and the occurrence of bronchitis in adolescents

OBJECTIVE

Previous studies have shown that an elevated BMI was associated with higher risks of bronchitis among children. The magnitude of how increase in BMI influencing the risk of incident bronchitis remained unexplored. The objective of this study is to assess the association between BMI and the incidence of bronchitis in the Taiwan Children Health Study.

DESIGN

A school-based prospective cohort study.

METHODS

We conducted a population-based prospective cohort study among seventh-grade school children in 14 Taiwanese communities. A total of 3,634 adolescents completed follow-up questionnaire in 2009. Associations between BMI and incident bronchitis were analyzed by multiple Poisson regression models, taking overdispersion into account.

RESULTS

Among eligible cohort participants without bronchitis at study entry, the proportion of overweight and obesity were 32.1% and 17.9%. Overweight was 40.7% and obesity was 27.7% among those with incident bronchitis. The BMI percentile categories showed significant increasing trends for bronchitis in total eligible children and in girls (P for trend <0.001). Overweight and obesity were both associated with increased risks of incident bronchitis. This association was significant in girls only while stratified by gender.

CONCLUSIONS

Our data showed that the BMI percentile and weight status were associated with higher risks of incident bronchitis in adolescents, especially in girls.

Traffic density in area of residence is associated with health-related quality of life in women, the community-based Hordaland Health Study

Vehicle traffic is increasing worldwide, and this is a major concern because traffic-related air pollution and noise may influence health. The aim of this study was to evaluate whether health-related quality of life (HRQoL) is associated with vehicle traffic density in area of residence. A total of 16,410 individuals, 40 to 45 years old, were asked to participate in this study (response rate: 55% for men, 66% for women). Using the 12-Item Short Form Health Survey (SF-12) questionnaire, both physical and mental HRQoL were investigated. Multiple linear regression analyses showed that women living in areas with high traffic density had significantly poorer physical HRQoL than women living in areas with moderate or low vehicle traffic density. There were no similar findings among men. Mental HRQoL was not associated with vehicle traffic density in the area of residence, neither for women nor for men. There is an association between high vehicle traffic density in residential area and reduced HRQoL in women.

Is obesity a risk factor for wheezing among adolescents? A prospective study in southern Brazil

PURPOSE

To investigate the effect of obesity at the start of adolescence on the prevalence, incidence and maintenance of chest wheezing among individuals aged 11-15 years in a birth cohort in a developing country.

METHODS

The seventh follow-up of the 1993 Pelotas birth cohort occurred in 2004 (individuals aged 10-11 years). Between January and August 2008, the eighth follow-up of the cohort was conducted. All the individuals of the original cohort who were alive (who were then adolescents aged between 14 and 15 years) were targets for the study. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to define wheezing. In addition to the body mass index (BMI), used to define obesity by the World Health Organization (WHO) criteria, we assessed skinfold thickness.

RESULTS

From the original cohort, 4,349 individuals were located (85.7% follow-up rate). The prevalence of chest wheezing at 11 and 15 years were 13.5% (95% CI: 12.5%-14.5%) and 12.1% (95% CI: 11.1%-13.1%), respectively. The prevalence of wheezing at both times was 4.5% (95% CI: 3.9%-5.1%) and the incidence of wheezing was 7.5% (95% CI: 6.7%-8.3%). Independent of the effect of various confounding variables, the prevalence of wheezing at 15 years was 50% greater among obese individuals than among eutrophic individuals at 11 years (RR 1.53; 95% CI: 1.14-2.05). The greater the skinfold tertile at 11 years, the higher the prevalence of wheezing at 15 years was (p = .011). Weight status and skinfolds did not present any association with incident wheezing. After controlling for confounding factors, the risk of persistent wheezing among obese individuals at 11 years was 1.82 (95% CI: 1.30-2.54).

CONCLUSIONS

Since obesity at the start of adolescence is associated with asthma symptom persistence, prevention and treatment of obesity may reduce avoidable healthcare costs and disease burden.

Association of asthma symptoms with cigarette smoking and alcohol consumption in Korean adolescents

The association of asthma symptoms with cigarette smoking and alcohol consumption in Korean adolescents was investigated in this study using the data of Korean Youth Risk Behavior Survey. Associated risk factors for experiencing asthma symptoms were explored in 3432 adolescents. In the symptomatic group, 21.7% were current smokers, compared to 10.9% in the asymptomatic group. Current smokers in the symptomatic group also smoked more cigarettes than those in the asymptomatic group. In the symptomatic group, 27.4% were current drinkers, compared to 17.9% in the asymptomatic group. Current drinkers in the symptomatic group were more likely to drink alcohol and to have experienced severe intoxication than those in the asymptomatic group. Participants who had been diagnosed within one year (odds ratio = 5.19, 95% confidence interval = 4.17-6.44) and those who had smoked over 20 days during the past 30 days (odds ratio = 1.77, 95% confidence interval = 1.26-2.49) were more likely to experience asthma symptoms. Healthcare providers should identify the risk behaviors of adolescents with asthma and counsel them and their parents simultaneously.

Sex and atopy influences on the natural history of rhinitis

PURPOSE OF REVIEW

Rhinitis is a common condition associated with significant under-recognized morbidity and impaired quality of life. The natural history of rhinitis is poorly characterized. Better understanding of its natural history and associated risk factors would improve the ability to effectively manage rhinitis in clinical practice. This review focuses on the current research findings on the natural history of rhinitis and how that is influenced by atopy and sex.

RECENT FINDINGS

Recent work from the Isle of Wight Birth Cohort Study has demonstrated that the prevalence of atopic rhinitis increases steadily in the first 18 years of life in both sexes. However, nonatopic rhinitis behaves differently during adolescence. Its prevalence decreases in boys but continues to increase in girls resulting in a female predominance after puberty. Numerous recent studies have proposed potential roles for sex-related and adipose-related hormonal changes in influencing the course of allergic disease. Further research is needed to establish mechanisms that could underlie such findings.

SUMMARY

Rhinitis becomes increasingly common through childhood, with prevalence during adolescence being mediated by differential effects of sex and atopy. Mechanisms to explain these findings await elucidation.

Conventional epidemiology underestimates the incidence of asthma and wheeze-a longitudinal population-based study among teenagers

Background

Because of shifts in the gender ratio and incidence and remission rates of asthma during the teen ages, the methodology of incidence studies among teenagers is important, i.e. if the time intervals between surveys are too long, the incident cases might not be properly identified. The aim was to study the impact of study design on the incidence rates of asthma and wheeze during the teen ages.

Methods

In a study about asthma and allergic diseases within the OLIN studies (Obstructive Lung Disease in northern Sweden), a cohort of school children (n = 3,430) was followed annually by questionnaire from age 8 yrs. In the endpoint survey (age 18 yrs) 2,582 (75% of original responders) participated. Incident cases from age 12-18 yrs were identified by two methods: annual questionnaire reports (AR) and baseline-endpoint surveys only (BE).

Results

The cumulative incidence of asthma and wheeze was significantly higher based on AR compared to BE. Compared to the incidence rates based on all the annual surveys, the calculated average annual rates based on BE were in general lower both among the boys and among the girls. There were no differences between boys and girls in incidence rates of asthma or wheeze during the early teen years. However, from the age of 15 years, the annual incidence rates were significantly or borderline significantly higher among girls than boys. At onset, the additional cases of current asthma identified by AR had significantly less severe asthma than those identified in BE (p < 0.02).

Conclusion

the size of the incidence of asthma and wheeze during the teen ages was influenced by study design. By using the conventional prospective study design with longer follow-up time, the incidence was underestimated.

Characterisation of asthma that develops during adolescence; findings from the Isle of Wight Birth Cohort

BACKGROUND

Understanding of adolescent-onset asthma remains limited. We sought to characterise this state and identify associated factors within a longitudinal birth cohort study.

METHODS

The Isle of Wight Whole Population Birth Cohort was recruited in 1989 (N=1456) and characterised at 1, 2, 4, 10 and 18-years. "Adolescent-onset asthma" was defined as asthma at age 18 without prior history of asthma, "persistent-adolescent asthma" as asthma at both 10 and 18 and "never-asthma" as those without asthma at any assessment.

RESULTS

Adolescent-onset asthma accounted for 28.3% of asthma at 18-years and was of similar severity to persistent-adolescent asthma. Adolescent-onset asthmatics showed elevated bronchial hyper-responsiveness (BHR) and atopy at 10 and 18 years. BHR in this group at 10 was intermediate to that of never-asthmatics and persistent-adolescent asthma. By 18 their BHR, bronchodilator reversibility and sputum eosinophilia was greater than never-asthmatics and comparable to persistent-adolescent asthma. At 10, males who later developed adolescent-onset asthma had reduced FEV(1) and FEF(25-75), while females had normal lung function but then developed impaired FEV(1) and FEF(25-75) in parallel with adolescent asthma. Factors independently associated with adolescent-onset asthma included atopy at 10 (OR=2.35; 95% CI=1.08-5.09), BHR at 10 (3.42; 1.55-7.59), rhinitis at 10 (2.35; 1.11-5.01) and paracetamol use at 18-years (1.10; 1.01-1.19).

CONCLUSIONS

Adolescent-onset asthma is associated with significant morbidity. Predisposing factors are atopy, rhinitis and BHR at age 10 while adolescent paracetamol use is also associated with this state. Awareness of potentially modifiable influences may offer avenues for mitigating this disease state.

The influence of gender and atopy on the natural history of rhinitis in the first 18 years of life

BACKGROUND

Longitudinal studies of the natural history of childhood and adolescent rhinitis are lacking.

OBJECTIVES

To investigate the natural history of rhinitis up to 18 years of age, and how that is influenced by gender and atopy.

METHODS

The Isle of Wight birth cohort was recruited in 1989 (n=1456). Questionnaire data on nasal symptoms (rhinitis) were collected at 1, 2, 4, 10 and 18 years of age. To define atopy, skin prick tests were conducted at 4, 10 and 18 years. The 12-month period prevalence plus positive and negative transitions (defined as change in disease status in two consecutive study assessments) were stratified by gender and atopic status.

RESULTS

Overall rhinitis prevalence increased from 5.4% at 4 years to 35.8% at 18 years (P<0.001), without gender difference. Atopic rhinitis prevalence increased steadily from 3.4% at 4 years to 27.3% at 18 years (P<0.001), was commoner in boys at 18 years (P=0.02) and associated with greater positive transition in boys from 10 to 18 years (P=0.01). Prevalence of non-atopic rhinitis also increased from 4 to 18 years (P=0.003) and was greater in girls at 18 years (P<0.001) reflecting higher female positive transition from 10 to 18 years (P<0.001). Non-atopic rhinitis negative transition (remission) was highest in early life and reduced in later childhood/adolescence.

CONCLUSION

Atopic rhinitis becomes increasingly common as children grow into adolescents, with stronger associations to male gender. Non-atopic rhinitis shows a female predominance at 18 years as girls 'grow into' it more during adolescence. Our findings suggest differential gender effects on the increasing prevalence of both atopic and non-atopic rhinitis in adolescence.

CLINICAL RELEVANCE

A better understanding of how gender and atopic status influence rhinitis during adolescence emerges from this study. Application of such knowledge could help to improve clinical recognition, judge prognosis and ultimately improve management of this common condition.

Childhood body mass index and risk of asthma in adolescence: a systematic review

Asthma and obesity, both of which are considered global health issues, affect approximately 300 million individuals worldwide. The observation that asthma and obesity tend to increase in parallel may indicate a potential link between these two conditions. The aim of this systematic review of the literature was to investigate the relationship between childhood nutritional status and incidence or persistence of asthma during adolescence. The principal eligibility criteria for selection of articles were including longitudinal analysis, and which measured of exposure during childhood or adolescence and outcome during adolescence. The systematic search initially returned 1563 unique articles. After inspection of titles and reading the abstracts of these articles, we chose 27 for full reading. Of these, 10 were selected to be included in the present review. Of the 10 selected studies, eight showed positive associations between overweight/obesity and asthma. Of these, two were independent of sex, three were found only among men and another three only among women. The present study shows strong evidence that, although the role of sex is not clear, obesity precedes, and is associated with, the persistence and intensity of symptoms of asthma.