The association of BMI and sedentary time with respiratory symptoms and asthma in 5th grade schoolchildren in Kaohsiung, Taiwan

The association of objectively measured sedentary time with asthma in US youth: A glimpse into the connection between obesity and asthma

BACKGROUND

Evidence suggests that asthma and obesity may share a common pathway, possibly through an increase in inflammation. Sedentary time is thought to promote both inflammation and obesity and previous studies have found a relationship between self-reported sedentary and asthma. However, the relationship between objectively measured sedentary time and asthma is not well described. We hypothesized that the association between asthma and sedentary time would not be present when physical activity was measured objectively, nor would objectively-measured sedentary time play an important role in the relationship between asthma and obesity.

OBJECTIVE

To determine if there is an association between asthma and objectively measured sedentary time in a large, nationally representative sample of the United States youth.

METHODS

Using the National Health and Nutrition Examination Survey 2003-2006, we assessed the relationship between asthma and sedentary time using objectively measured and self-reported measures of sedentary time, in 6-19 years-old subjects with available accelerometry data. We used multivariate logistic regression analysis to determine associations between the risk of asthma and sedentary time controlling for accelerometer wear time, gender, age, race/ethnicity, body mass index percentile, and moderate-to-vigorous physical activity (MVPA).

RESULTS

In this cohort, youth with asthma self-reported more time in sedentary behavior, specifically computer time, than those without asthma (p = 0.01). However, when sedentary time was measured objectively by accelerometry, sedentary time did not differ between youth with and without asthma (421 min [standard deviation 4.2] versus. 414 min [standard deviation 7.8] [p = 0.38]). Controlling for measures of activity, such as MVPA, or time spent in long versus short bouts of sedentary time did not modify our results.

CONCLUSIONS

Differences in sedentary time by self-report between those with and without asthma were not born out by examining sedentary time using objective measures. Further work is necessary to examine the complex interaction among inactivity, obesity, and asthma over time, specifically focusing on whether the type of sedentary activity (e.g., computer vs. television time) is important.

Risk factors of chronic cough in China: a systematic review and meta-analysis

OBJECTIVES

Risk factors of chronic cough in China have not been systematically analyzed and we hypothesized that risk factors of chronic cough might have distinct characteristics in China. Hence, we performed this meta-analysis focusing on the potential risk factors of chronic cough in China.

METHODS

We searched 7 databases for studies published before May 8, 2021. This systematic review was performed in accordance with the PRISMA checklist.

RESULTS

A total of 33 eligible articles were identified and included in this systematic review, and 28 studies were included in the meta-analysis. Our results showed that allergy (OR: 3.72; 95% CI: 1.85-7.47), nasal/sinusitis diseases (OR: 3.56; 95% CI: 2.02-6.29), family history of allergy (OR = 1.74; 95% CI: 1.59-1.90), family history of chronic respiratory diseases (OR = 1.67; 95% CI: 1.47-1.91), exposure to pollutants (OR = 1.60; 95% CI: 1.26-2.04), passive smoking (OR = 1.44; 95% CI: 1.32-1.57), and exposure to pets (OR = 1.37; 95% CI: 1.18-1.58) were risk factors for chronic cough in China.

CONCLUSIONS

Our study indicated some potential risk factors of chronic cough in China, which provides useful epidemiological information for managing chronic cough in China and is worthy as a reference for future global investigations.

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

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.

Associations between central obesity and asthma in children and adolescents: a case-control study

INTRODUCTION

Evidence supports a significant yet weak association between high-body weight and asthma in children. However, most studies investigating the obesity-asthma link use Body Mass Index (BMI) to evaluate body fatness. The relationship between body fat distribution and asthma remains largely unknown, especially in children. This pediatric case-control investigation examined associations between central obesity/high-body weight and asthma diagnosis.

METHODS

Five-hundred and fourteen children (217 physician diagnosed asthma cases and 297 healthy controls) of 5-11 years were recruited. Height, weight and waist circumference were measured. Asthma symptoms, past medical history, personal lifestyle, socioeconomic status, diet and physical activity history were also collected.

RESULTS

A higher proportion of children with asthma were centrally obese [(≥90th waist percentile) 15.2 vs. 9.4%, p<0.0001; (≥90th waist-to-height ratio percentile) 39.6 vs. 24.2%, p<0.0001)]. Regression analyses revealed that centrally obese children were more likely to have asthma (high-waist circumference (OR = 1.99, 95% CI: 1.07-3.68) and high-waist circumference to height ratio (OR = 2.24, 95% CI: 1.47-3.40), following adjustment for various confounders. Overweight/obese participants (BMI defined) were more likely to be asthmatic [odds ratio (OR) = 1.52, 95% confidence interval (CI): 1.03-2.70)] when compared to controls.

CONCLUSIONS

Presence of central obesity and high-body weight (at least overweight) as assessed by waist circumference, waist-to-height ratio, and BMI are associated with asthma diagnosis. More studies are needed, especially in children and adolescents, to confirm these findings and better understand how body fat distribution impacts the obesity-asthma relationship.

Physical activity and asthma: a systematic review and meta-analysis

INTRODUCTION

This review aims to give an overview of available published evidence concerning the association between physical activity and asthma in children, adolescents and adults.

METHODS

We included all original articles in which both physical activity and asthma were assessed in case-control, cross-sectional or longitudinal (cohort) studies. Excluded were studies concerning physical fitness, studies in athletes, therapeutic or rehabilitation intervention studies such as physical training or exercise in asthma patients. Methodological quality of the included articles was assessed according to the Newcastle-Ottawa Scale (NOS).

RESULTS

A literature search was performed until June 2011 and resulted in 6,951 publications derived from PubMed and 1,978 publications from EMBASE. In total, 39 studies met the inclusion criteria: 5 longitudinal studies (total number of subjects n = 85,117) with physical activity at baseline as exposure, and asthma incidence as outcome. Thirty-four cross-sectional studies (n = 661,222) were included. Pooling of the longitudinal studies showed that subjects with higher physical activity levels had lower incidence of asthma (odds ratio 0.88 (95% CI: 0.77-1.01)). When restricting pooling to the 4 prospective studies with moderate to good study quality (defined as NOS≥5) the pooled odds ratio only changed slightly (0.87 (95% CI: 0.77-0.99)). In the cross-sectional studies, due to large clinical variability and heterogeneity, further statistical analysis was not possible.

CONCLUSIONS

The available evidence indicates that physical activity is a possible protective factor against asthma development. The heterogeneity suggests that possible relevant effects remain hidden in critical age periods, sex differences, or extremes of levels of physical activity (e.g. sedentary). Future longitudinal studies should address these issues.

Systematic review of sedentary behaviour and health indicators in school-aged children and youth

Accumulating evidence suggests that, independent of physical activity levels, sedentary behaviours are associated with increased risk of cardio-metabolic disease, all-cause mortality, and a variety of physiological and psychological problems. Therefore, the purpose of this systematic review is to determine the relationship between sedentary behaviour and health indicators in school-aged children and youth aged 5-17 years. Online databases (MEDLINE, EMBASE and PsycINFO), personal libraries and government documents were searched for relevant studies examining time spent engaging in sedentary behaviours and six specific health indicators (body composition, fitness, metabolic syndrome and cardiovascular disease, self-esteem, pro-social behaviour and academic achievement). 232 studies including 983,840 participants met inclusion criteria and were included in the review. Television (TV) watching was the most common measure of sedentary behaviour and body composition was the most common outcome measure. Qualitative analysis of all studies revealed a dose-response relation between increased sedentary behaviour and unfavourable health outcomes. Watching TV for more than 2 hours per day was associated with unfavourable body composition, decreased fitness, lowered scores for self-esteem and pro-social behaviour and decreased academic achievement. Meta-analysis was completed for randomized controlled studies that aimed to reduce sedentary time and reported change in body mass index (BMI) as their primary outcome. In this regard, a meta-analysis revealed an overall significant effect of -0.81 (95% CI of -1.44 to -0.17, p = 0.01) indicating an overall decrease in mean BMI associated with the interventions. There is a large body of evidence from all study designs which suggests that decreasing any type of sedentary time is associated with lower health risk in youth aged 5-17 years. In particular, the evidence suggests that daily TV viewing in excess of 2 hours is associated with reduced physical and psychosocial health, and that lowering sedentary time leads to reductions in BMI.

A medical nutrition therapy primer for childhood asthma: current and emerging perspectives

Asthma is the most common chronic disease in children. Prevalence has increased in the past 2 decades and has reached a plateau of approximately 9% of children in the United States, affecting about 6.7 million children. The increased prevalence of childhood asthma has paralleled the increased prevalence in childhood obesity. Changes in diet have also been implicated in the increased prevalence of asthma, among other risk factors. The main symptoms of asthma (ie, wheezing, coughing, and chest tightness) require medical evaluation and monitoring. The cornerstone of asthma management is medication therapy, frequently consisting of inhaled bronchodilators and corticosteroids and, when needed, therapy of corticosteroids by mouth. As part of the multidisciplinary management of this chronic disease, nutrition assessment and follow-up in childhood asthma is necessary to identify and address relevant nutrition-related problems. These problems can involve food-medication interactions, obesity, gastroesophageal reflux disease, food allergies, and other issues; therefore, individualized medical nutrition therapy is warranted. Finally, counseling to achieve a healthy balanced diet is recommended for overall health and weight management. A recent but small number of descriptive investigations agree that adherence to a Mediterranean dietary pattern can be associated with a decreased risk of current asthma symptoms in children. Although this evidence is promising, food interventions are required to substantiate an evidence-based foundation for medical nutrition therapy in childhood asthma. At this time, there is no known health risk if a Mediterranean diet is adopted.