Asthma and all-cause mortality in children and young adults: a population-based study

Prevalence and risk factors for childhood asthma: a systematic review and meta-analysis

BACKGROUND

This study aimed to systematically review and perform a meta-analysis on epidemiological studies in order to estimate the global and regional prevalence and to identify risk factors associated with childhood asthma.

METHODS

A comprehensive search of the PubMed, Embase, and Cochrane Library electronic databases was conducted for relevant literature published from their inception to March 31, 2023. The primary endpoint was the prevalence of childhood asthma. Secondary endpoint focused on the identification of risk factors associated with childhood asthma.

RESULTS

A total of 1,547,404 children participated in the 164 studies selected for the meta-analysis. The overall prevalence of childhood asthma was 10.2% (95% CI: 9.5-11.0%), while the prevalence of childhood asthma in Asia, Europe, Latin America, North America, Oceania, Africa, or Eurasia were 10% (95%CI: 7-13%), 9% (95%CI: 7-12%), 14% (95%CI: 9-20%), 13% (95%CI: 12-14%), 23% (95%CI: 19-28%), 11% (95%CI: 7-19%), and 8% (95%CI: 2-27%), respectively. Moreover, the identified risk factors for childhood asthma included older age, male sex, obesity, parental smoking, high education of the mother, premature birth, cesarean section, no breastfeeding, family history of asthma, rhinitis, eczema, pets, high density of road traffic, meat, margarine, fast food, paracetamol use, and antibiotic use.

CONCLUSION

Childhood asthma is common, and the prevalence of asthma is highest in Oceania, with a lower prevalence in Eurasia. Moreover, the risk factors for childhood asthma were comprehensively identified, and health education should be provided to prevent modifiable factors.

Recent increase in asthma mortality in Brazil: a warning sign for the public health system

OBJECTIVE

To provide an update on asthma mortality trends in Brazil and its regions between 2014 and 2021.

METHODS

This was a retrospective descriptive observational study based on asthma mortality data from the Brazilian National Ministry of Health Mortality Database for the 2014-2021 period.

RESULTS

In the study period, there were 18,584 asthma deaths in Brazil, with an annual increase of 2.5%, corresponding to 0.03 deaths/100,000 population (95% CI, 0.01-0.04; p = 0.01). The northeastern region of the country had the highest prevalence of asthma deaths (1.50 deaths/100,000 population), and the southern region showed the greatest variation in the study period (44%). We observed a higher proportion of deaths among females and elderly patients, and when analyzing asthma deaths by place of occurrence, we observed that 28% of all deaths occurred at home.

CONCLUSIONS

Asthma mortality remains high and shows an increasing trend for the first time in the past decades. This constitutes an important public health concern, given the treatable nature of the disease.

Supraventricular tachycardia diagnosis in asthma patients is associated with adverse health outcomes

INTRODUCTION

Supraventricular tachycardia (SVT) can occur during treatment of an acute asthma exacerbation. There are, however, no data on the long-term outcomes of children who are diagnosed with both asthma and SVT. This study aims to analyze the impact of SVT in asthmatic children on mortality and/or cardiac arrest, hypothesizing asthmatic subjects with SVT have increased mortality and/or cardiac arrest compared to asthmatic subject with no-SVT.

METHODS

This was a retrospective cohort study, utilizing the TriNetX© electronic health record (EHR) database that included asthmatic subjects 2-18 years of age. The study population was divided into two groups (subjects with SVT diagnosis and no-SVT diagnosis). Data related to demographics, diagnostic, procedural, and medication codes were collected. The primary outcome was any death and/or cardiac arrest in a patient after the first asthma diagnosis date.

RESULTS

This study included 91,066 asthmatic subjects (244 [0.27%] with SVT and 90,822 [99.73%] with no-SVT). Multivariable logistic regression analysis demonstrated that after controlling for demographic and clinical features, the odds of all-cause death and/or cardiac arrest after the first reported asthma exacerbation was significantly higher in asthmatic children with SVT compared to no-SVT (odds ratio [OR]: 4.30, confidence interval [CI]: 2.50-7.39, p < .001).

CONCLUSIONS

Our large nationwide EHR study suggests that asthmatic pediatric patients with documented SVT diagnosis at any point in their EHR may be at increased risk of adverse health outcomes compared to no-SVT. Further studies are needed to determine the factors contributing to the increased risk of mortality and/or cardiac arrest in children with asthma and SVT.

Small Airways Obstruction and Mortality: Findings From the UK Biobank

BACKGROUND

Small airways obstruction (SAO) is common in general populations. It has been associated with respiratory symptoms, cardiometabolic diseases, and progression to COPD over time. Whether SAO predicts mortality is largely unknown.

RESEARCH QUESTION

Is spirometry-defined SAO associated with increased mortality?

METHODS

Data were analyzed from 252,877 adult participants, aged 40 to 69 years at baseline, in the UK Biobank who had provided good-quality spirometry measurements. SAO was defined as the ratio of the forced expiratory volume in 3 s to the forced expiratory volume in 6 s less than the lower limit of normal. SAO was considered to be isolated if present when the FEV1/forced expiratory volume in 6 s ratio was normal (ie, greater than the lower limit of normal). A multivariable Cox regression model was used to assess the association of SAO, and isolated SAO, with all-cause and disease-specific mortality. Sex differences were investigated in these associations, and the primary analysis was repeated, excluding those who ever smoked. All models were adjusted for potential confounders such as sex, BMI, smoking status, smoking pack-years, assessment center, Townsend deprivation index, and ethnicity.

RESULTS

A total of 59,744 participants with SAO were identified, of whom 24,004 had isolated SAO. A total of 5,009 deaths were reported over a median of 12.8 years of follow-up. Participants with SAO had increased all-cause (hazard ratio [HR], 1.31; 95% CI, 1.26-1.36), cardiovascular (HR, 1.39; 95% CI, 1.29-1.51), respiratory (HR, 2.20; 95% CI, 1.92-2.51), and neoplasm (HR, 1.23; 95% CI, 1.17-1.29) mortality risk. These associations were not modified by sex. However, in those who never smoked, only respiratory and cardiovascular mortality risk was associated with SAO. Isolated SAO was also associated with an increased mortality risk (HR, 1.14; 95% CI, 1.07-1.20).

INTERPRETATION

Individuals with SAO have an increased risk of all-cause and disease-specific mortality. Further studies are needed to determine whether SAO causes mortality or is a marker of underlying disease.

Association between blood heavy metal element and all-cause mortality in asthmatic adults: a cohort study

Asthma start, development, and exacerbation have all been linked in numerous studies to exposure to a variety of metal elements. However, there is still a dearth of epidemiological data linking heavy metal exposure to death in asthmatics. The investigation included 2432 eligible adults with asthma. The study examined the possible correlation between blood heavy metal levels and all-cause mortality. This was done by utilizing Cox proportional hazards models, restricted cubic spline (RCS), threshold effect models, and CoxBoost models. Subgroup analyses were conducted to investigate the associations between blood metal levels and all-cause mortality among distinct asthmatic populations. An inverse association was found between blood selenium and all-cause mortality in asthmatics, while blood manganese showed a positive association with all-cause mortality. However, there were no significant connections found between blood lead, cadmium, mercury, and all-cause mortality via multivariate Cox proportional hazard models. In model 3, after accounting for all factors, all-cause mortality dropped by 10% for every additional 10 units of blood selenium (μg/L) and increased by 6% for every additional unit of blood manganese (μg/L). The RCS and threshold effect model found a U-shaped correlation between blood selenium, blood manganese, and all-cause mortality. The lowest all-cause mortality among asthmatics was observed when blood selenium and manganese were 188.66 μg/L and 8.47 μg/L, respectively. Our investigation found a U-shaped correlation between blood selenium levels, blood manganese levels, and all-cause mortality in asthmatic populations. Optimizing dietary selenium intake and effectively managing manganese exposure could potentially improve the prognosis of asthma.

Dietary antioxidant and inflammatory potential in asthmatic patients and its association with all-cause mortality

BACKGROUND

The occurrence and progression of asthma can be influenced by the components in food. Our study aims to determine whether dietary antioxidant and inflammatory potential are associated with the risk of mortality in asthma patients.

METHODS

Participants from the 2001-2018 National Health and Nutrition Examination Survey (NHANES) aged 20 years and older with a diagnosis of asthma were included. Mortality status was obtained according to death certificate records from the National Death Index. The antioxidant and inflammatory potential of the diet was assessed using two widely used and dependable indices, Composite Dietary Antioxidant Index (CDAI) and Dietary Inflammatory Index (DII). Restricted cubic spline (RCS) regression was used to analyze the non-linear relationship between the two indexes and mortality. Multivariable Cox proportional risk models were used to estimate hazard ratio and 95% confidence intervals for mortality. Finally, the relationship between CDAI and DII was analyzed.

RESULTS

A total of 4698 NHANES participants represented 23.2 million non-institutionalized residents of the US were enrolled in our study. Patients with higher CDAI or lower DII exhibited longer survival times. RCS regression showed a linear relationship of CDAI or DII with mortality. In the Cox regression, both crude and adjusted models demonstrated that higher CDAI or lower DII was linked to a reduced risk of all-cause mortality. Similar associations were found in subgroup analysis. Finally, a negative relationship was found between CDAI and DII.

CONCLUSION

Reducing pro-inflammatory or increasing antioxidant diets could reduce all-cause mortality among adult asthma patients.

Caregiver burden among parents of school-age children with asthma: a cross-sectional study

Objective

To investigate the caregiver burden of parents of school-age children with asthma and analyze the factors influencing their caregiver burden.

Methods

A convenience sampling method was used to select 366 parents of school-age children with asthma who visited the outpatient departments of three tertiary hospitals in Sichuan Province, China, from January 2021 to July 2021. A general information questionnaire and the Caregiver Burden Inventory (CBI) were used to assess the current caregiver burden and analyze the influencing factors.

Results

The caregiver burden score of parents of school-age children with asthma was 27 (17, 39), with 40.43% of parents experiencing moderate to high levels of burden. Detailed results of univariate analysis showed that there were significant differences in caregiver burden scores based on parents' gender, highest education level, number of children, occupation, family history of asthma, monthly family income, annual medical expenses for the child, child's gender, whether the child had undergone lung function tests, number of emergency visits due to asthma exacerbation in the past 3 months, and whether the child had missed school due to asthma exacerbation in the past 3 months (p < 0.1). Detailed results of multivariate analysis showed that parents' gender, occupation, family history of asthma, monthly family income, annual medical expenses for the child, number of emergency visits due to asthma exacerbation in the past 3 months, and whether the child had missed school due to asthma exacerbation in the past 3 months were independent risk factors for caregiver burden in parents of school-age children with asthma (p < 0.05).

Conclusion

Parents of school-age children with asthma experience a certain level of caregiver burden, with over one-third of parents experiencing moderate to high levels of burden. Being a mother, being a worker, having no family history of asthma, having low monthly family income, having high annual medical expenses for the child, having frequent emergency visits due to asthma exacerbation in the past 3 months, and having missed school due to asthma exacerbation in the past 3 months are independent risk factors for caregiver burden in parents of school-age children with asthma, healthcare providers should develop feasible coping strategies, such as paying attention to caregivers' psychological condition to reduce the burden of caring for parents of school-age children with asthma. The entire society should also make efforts in improving social support and strengthening healthcare coverage in order to achieve the aforementioned goals.

Level of Education Modifies Asthma Mortality in Norway and Sweden. The Nordic EpiLung Study

Background and Aim

The relationship between socioeconomic status (SES), asthma and mortality is complex and multifaceted, and it is not established if educational level modifies the association between asthma and mortality. The aim was to study the association between asthma and mortality in Sweden and Norway and to what extent educational level modifies this association.

Participants and Methods

Within the Nordic EpiLung Study, >56,000 individuals aged 30-69 years participated in population-based surveys on asthma and associated risk factors in Sweden and Norway during 2005-2007. Data on educational level and 10-year all-cause mortality were linked by national authorities. The fraction of mortality risk attributable to asthma was calculated, and Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for mortality related to asthma, stratified by educational level.

Results

In total, 5.5% of all deaths was attributed to asthma. When adjusted for potential confounders, the HR for mortality related to asthma was 1.71 (95% CI 1.52-1.93). Those with primary level of education had higher hazard of all-cause death related to asthma than those with tertiary level (HR 1.80, 95% CI 1.48-2.18, vs HR 1.39, 95% CI 0.99-1.95).

Conclusion

Asthma was associated with an overall 71% increased all-cause mortality and 5.5% of deaths can be attributed to asthma. Educational levels modified the risk of mortality associated with asthma, with the highest risk among those with primary education.

Serum autophagy protein 5 is positively related to T helper 2/T helper 1 ratio, inflammation, and exacerbation in adult asthma patients

BACKGROUND

Autophagy protein 5 (ATG5) regulates airway epithelial cell autophagy, immune response, and inflammation, which is involved in asthma progression. This study aimed to evaluate ATG5 levels and its clinical roles in adult asthma patients.

METHODS

Totally, 200 adult asthma patients and 100 healthy controls (HCs) were enrolled in this case-control study. Subsequently, serum ATG5 was measured by enzyme-linked immunosorbent assay.

RESULTS

ATG5 was increased in asthma patients compared with HCs [median (interquartile range): 44.2 (31.7-77.8) vs. 23.2 (16.7-39.2) ng/mL] (P < 0.001). In asthma patients, ATG5 was positively related to male gender (P = 0.022), a family history of asthma (P = 0.035), eosinophil count (P < 0.001), and immune globulin E (P < 0.001), while it was negatively correlated with forced expiratory volume in 1 s (FEV1)/forced vital capacity (P < 0.001) and FEV1 (Predicted) (P < 0.001). Meanwhile, ATG5 was inversely associated with T helper (Th) 1 cells (P = 0.008), while it was positively linked with Th2 cells (P < 0.001), Th2/Th1 ratio (P < 0.001), interleukin (IL)-4 (P = 0.002), and IL-4/interferon-γ ratio (P = 0.015). Additionally, ATG5 was positively correlated with tumor necrosis factor-α (P < 0.001), IL-1β (P = 0.001), IL-6 (P = 0.003), and IL-17 (P = 0.029). Notably, ATG5 was elevated in asthma patients at exacerbation compared to those at remission [median (interquartile range): 53.6 (37.6-90.0) vs. 35.6 (28.2-51.5) ng/mL] (P < 0.001). It was also noteworthy that ATG5 was positively linked with exacerbation severity in asthma patients (P = 0.005).

CONCLUSION

Serum ATG5 is related to increased Th2/Th1 ratio, inflammation, exacerbation risk and severity in adult asthma patients, which serves as a candidate marker for the management of asthma. However, further validation is still needed.

The effect of pulmonary rehabilitation on childhood asthma: a systematic review and meta-analysis

INTRODUCTION

Pulmonary rehabilitation (PR) is a comprehensive nursing intervention for lung function improvement in patients with respiratory diseases. This systematic review focused on further exploration of the unclear impacts of PR on childhood asthma.

EVIDENCE ACQUISITION

Web of Science, Cochrane Library, Embase, PubMed, and other databases were searched until May 2021. Randomized controlled trials (RCTs) comparing the effects of PR (including exercise training and education) and routine care on childhood asthma were included. Study selection, data extraction, and bias risk assessment were performed independently by two investigators.

EVIDENCE SYNTHESIS

Fourteen RCTs involving 1401 patients were included. Relative to the control group, the total scores of the asthma quality of life questionnaire were evidently improved in the experimental group, including motor domain scores (MD=0.88, 95% CI: 0.67-1.09), symptom domain scores (MD=1.23, 95% CI: 0.61-1.85), and affective domain scores (MD=1.38, 95% CI: 0.63-2.14). Besides, 6-min walk distance (MD=2.01, 95% CI: 0.86-3.15) and asthma control test (MD=0.31, 95% CI: 0.02-0.60) were prominently improved. However, the maximum oxygen uptake (MD=0.81, 95% CI: -0.2 to 1.82) was not markedly improved. The forced expiratory volume in 1 s (MD=0.42, 95% CI: -0.29 to 1.13), and forced vital capacity (MD=0.07, 95% CI: -0.14 to 0.28) were not remarkably improved. There was an evident improvement in the peak expiratory flow (MD=1.22, 95% CI: 0.15-2.30).

CONCLUSIONS

PR improves some lung functions, exercise tolerance and the quality of life of children with asthma, and it might work as a supplementary therapy for the treatment of childhood asthma. Moreover, more RCTs of high quality and in large sample size are needed for further confirmation.

Prenatal opioid exposure and risk of asthma in childhood: a population-based study from Denmark, Norway, and Sweden

Background: Opioids may modulate the immune function through opioid receptors on immune cells. Long-term consequences of prenatal opioid exposure on the immune system, such as childhood asthma, are unknown. Objectives: To investigate whether prenatal opioid exposure is associated with the risk of childhood asthma. Methods: Cohort study using linked nationwide registers in Denmark (1996-2015), Norway (2005-2015), and Sweden (2006-2013). Children born by mothers who were chronic opioid analgesics users before pregnancy (n = 14,764) or who were receiving opioid maintenance therapy (OMT) before or during pregnancy (n = 1,595) were identified based on information from each of the medical birth registers and prescription registers. Long-term opioid analgesics exposed children were compared to short-term exposed or unexposed, whereas OMT exposed children were compared to OMT unexposed. Asthma among children ≥1 years of age was defined as two or more filled prescriptions of antiasthmatic medication within 365 days, or a diagnosis of asthma. Hazard ratios (HRs) were calculated using Cox proportional hazards regression with attained age as the time scale. Inverse probability of treatment weights based on propensity scores were applied to adjust for measured confounders. Individual level data from Norway and Sweden were pooled, whereas individual level data from Denmark were analyzed separately. For the opioid analgesics comparisons, adjusted HRs (aHR) from the combined Norwegian/Swedish data and the Danish data were pooled in a fixed-effects meta-analysis. Results: For the opioid analgesics cohort, no increased risk of asthma was observed in long-term exposed children neither compared with unexposed [aHR = 0.99 (95% CI 0.87-1.12)], nor compared with short-term exposed [aHR = 0.97 (0.86-1.10)]. No increased risk of asthma was observed in OMT exposed compared with OMT unexposed children [Norway/Sweden: aHR = 1.07 (0.60-1.92), Denmark: aHR = 1.25 (0.87-1.81)]. Results from sensitivity analyses, where potential misclassification of the outcome and misclassification of OMT exposure were assessed, as well as starting follow-up at 6 years of age, showed that the estimates of association were generally robust. Conclusion: We found no association between prenatal exposure to opioids and risk of childhood asthma. Results were consistent across two different opioid exposure groups with different confounder distributions.

[A Study of the Prevalence of Asthma in the General Population in Spain]

Introduction

Asthma is a disease with high prevalence, which affects all age groups and generates high health and social care costs. Studies carried out in a number of populations show great variability in its prevalence, even in geographically close populations, with data suggesting a relevant influence of socio-economic factors. At present, we do not have reliable data on the prevalence of this disease in the adult population of Spain. The objectives of this study are to estimate the prevalence of asthma in the Spanish population for those aged 18-79, to describe the variability between autonomous communities, to estimate the prevalence of under and overdiagnosis, to analyse the prevalence of uncontrolled asthma and steroid-dependent asthma, to evaluate the health care cost, to identify the most frequent phenotypes and to establish a starting point to evaluate the temporal trend with subsequent studies.

Methods

A cross-sectional, two-stage study will be carried out, including patients from 50 catchment areas. The study will be carried out in 3 phases: 1) screening and confirmation in the clinical history, in which patients with a previously correctly established diagnosis of asthma will be identified; 2) diagnosis of asthma to evaluate patients without a confirmed or excluded diagnosis; 3) characterization of asthma, where the characteristics of the asthmatic patients will be analysed, identifying the most frequent phenotypes.

Discussion

It seems necessary and feasible to carry out an epidemiological study of asthma in Spain to identify the prevalence of asthma, to optimize healthcare planning, to characterize the most frequent phenotypes of the disease, and to evaluate inaccurate diagnoses.

Benchmarking omics-based prediction of asthma development in children

BACKGROUND

Asthma is a heterogeneous disease with high morbidity. Advancement in high-throughput multi-omics approaches has enabled the collection of molecular assessments at different layers, providing a complementary perspective of complex diseases. Numerous computational methods have been developed for the omics-based patient classification or disease outcome prediction. Yet, a systematic benchmarking of those methods using various combinations of omics data for the prediction of asthma development is still lacking.

OBJECTIVE

We aimed to investigate the computational methods in disease status prediction using multi-omics data.

METHOD

We systematically benchmarked 18 computational methods using all the 63 combinations of six omics data (GWAS, miRNA, mRNA, microbiome, metabolome, DNA methylation) collected in The Vitamin D Antenatal Asthma Reduction Trial (VDAART) cohort. We evaluated each method using standard performance metrics for each of the 63 omics combinations.

RESULTS

Our results indicate that overall Logistic Regression, Multi-Layer Perceptron, and MOGONET display superior performance, and the combination of transcriptional, genomic and microbiome data achieves the best prediction. Moreover, we find that including the clinical data can further improve the prediction performance for some but not all the omics combinations.

CONCLUSIONS

Specific omics combinations can reach the optimal prediction of asthma development in children. And certain computational methods showed superior performance than other methods.

Particulate matter pollution and asthma mortality in China: A nationwide time-stratified case-crossover study from 2015 to 2020

BACKGROUND

A national and comprehensive evaluation is lacking on the relationship between short-term exposure to submicron particulate matter (PM₁) pollution and asthma mortality.

METHODS

Data was obtained from 29,553 asthma deaths from the China National Mortality Surveillance System from 2015 to 2020. We used a bilinear interpolation approach to estimate each participant's daily ambient particulate matter pollution and meteorological variables exposure based on their geocoded residential address and a 10 km × 10 km grid from China High Air Pollutants and the fifth generation of European ReAnalysis-Land reanalysis data set. The associations were estimated using a time-stratified case-crossover design and conditional logistic regressions.

RESULTS

Our results revealed significant associations between short-term exposure to various particulate matter and asthma mortality. The 5-day moving average of particulate matter exposure produced the most pronounced effect. Compared to fine particulate matter (PM_2.5) and inhalable particulate matter (PM₁₀), significantly stronger effects on asthma mortality related to PM₁ pollution were noted. The ERs% for asthma mortality associated with each interquartile range (IQR) increase of exposures to PM₁ (IQR: 19.2 μg/m³) was 5.59% (95% CI: 2.11-9.19), which is 14% and 22% higher than that for PM_2.5 (IQR: 32.0 μg/m³, 4.82% (95% CI: 1.84-7.90)) and PM₁₀ (IQR: 52.2 μg/m³, 4.37% (95% CI: 1.16-7.69)), respectively. The estimates remained consistent in various sensitivity analyses.

CONCLUSIONS

Our study provided national evidence that acute exposures to various ambient particulate matter pollution can increase mortality due to asthma in China, highlighting stronger associations with ambient PM₁ than PM_2.5 and PM₁₀. China needs to adjust the current ambient air quality standards urgently and pay greater attention to the adverse health effects of PM₁.

Health Effects of the Asthma Care Program under the Universal Coverage Scheme in Children and Young Adults in Thailand

This study aimed to evaluate the effect of the asthma care program available under the Universal Coverage Scheme (UCS) in Thailand on hospital admissions per 100,000 population, its regional and seasonal variation, readmission within 28 days, and the asthma-specific fatality rate of patients aged 0–29 years in 2009–2016 compared with those in 2007–2008. A retrospective study was conducted using data sources from the UCS register and in-patient databases from the National Health Security Office (NHSO), Thailand. Hospital admissions per 100,000 population was the highest among those aged 0–4 years, but the trends decreased from 470.8 to 288.1 per 100,000 population in 2010–2014. The hospital admission rates were high in Southern Thailand and common in rainy seasons. The readmission rates within 28 days slightly decreased in all age groups in 2016 compared to those in 2007. The case fatality rate of patients aged 20–29 years decreased from 0.40% in 2007 to 0.34% in 2016. The readmission rate within 28 days and case fatality rate were the highest in patients aged 20–29 years. In conclusion, the asthma hospital admission, readmission, and case fatality rates declined over time along with the investment in the asthma care program under the UCS in Thailand. The highest hospital admission rates in patients aged 0–4 years and the readmission and case fatality rates in patients aged 20–29 years should be given more attention. Recordings of individual service utilization data in asthma patients, including quality of care provided, should be monitored to improve the asthma care system.

Association Between Asthma and All-Cause Mortality and Cardiovascular Disease Morbidity and Mortality: A Meta-Analysis of Cohort Studies

Background

Asthma and cardiovascular disease (CVD) share many risk factors. Previous meta-analyses indicated that asthma is associated with an increased risk of CVD and all-cause mortality, but these studies were limited by unstandardized search strategies and the number of articles included.

Objective

We sought to systematically synthesize evidence investigating the impact of asthma on all-cause mortality and CVD morbidity and mortality.

Methods

We searched in PubMed and EMBASE for observational cohort studies (inception dates to November 10, 2021) that had both asthma groups and control groups. We also manually searched the reference lists of correlative articles to include other eligible studies. Data for associations between asthma and all-cause mortality and CVD morbidity and mortality were needed.

Results

We summarized the findings from 30 cohort studies comprising 4,157,823 participants. Asthma patients had increased CVD morbidity [relative risk (RR) = 1.28, 95% confidence interval (CI) = 1.16–1.40] and increased CVD mortality (RR = 1.25, 95% CI = 1.14–1.38). Asthma patients also had increased risk of all-cause mortality (RR = 1.38, 95% CI = 1.07–1.77). In subgroup analyses, female asthma patients had a higher risk of CVD morbidity and all-cause mortality than male asthma patients, and late-onset asthma patients had a higher risk of CVD morbidity than early-onset asthma patients.

Conclusion

Asthma patients have increased risk of all-cause mortality and CVD morbidity and mortality. This information reminds clinicians to be aware of the risk of CVD and all-cause mortality in asthma patients.

Systematic Review Registration

http://www.crd.york.ac.uk/PROSPERO/, PROSPERO, identifier: CRD 42021290082.

Burden of childhood and adolescence asthma in Nigeria: Disability adjusted life years

BACKGROUND

A better representation of the burden of childhood asthma should rely on both morbidity and mortality and not only mortality. This will reduce the dearth of information on burden of childhood asthma, and enhance evidence-based decision-making. In this study, burden of childhood asthma was estimated, using disability-adjusted-life-years (DALYs), factoring in the disability weights for asthma, age at mortality and life expectancy.

METHODS

The study was conducted at the University of Nigeria Teaching Hospital, Enugu. An Interviewer Administered Questionnaire was used to collect information from parents of children with asthma who presented to respiratory clinics regarding level of their asthma control (controlled, partially controlled and poorly controlled asthma), their age distributions, and gender. The prevalence of asthma, prevalence of associated disability, and case-fatality were obtained from previous publications. The DALYs were estimated by adding together the years lost to disability (YLDs) and years lost to life (YLLs) to asthma (DALYs = YLD + YLL). DALYs were dis-aggregated by age group and by whether their asthma were controlled, partially controlled and poorly controlled.

RESULTS

A total of 66 children with asthma were studied. The proportion of the subjects with controlled, partially controlled and poorly controlled asthma were 26 (39.4%), 31 (47%), and 9 (13.6%) respectively. The subjects that had some form of asthma-related disability were 16 (24.3%). Childhood asthma caused 23.6-34.24 YLLs per 1000 population, 0.01-1.28 YLDs per 1000 population and 24.23-34.41 DALY per 1000 population. There was minimal difference in DALYs across the three clinical categories, but this was consistently higher among older children 12-17 years. The estimated national DALYs was 407820.2, reflecting about of 1.6% of the global all age (children and adults) DALYs of 24.8 million.

CONCLUSION

The DALYs due to childhood asthma were high and did not vary much across the clinical categories, but increased with age. This imperatively necessitates the de-emphasis on just clinical responses as an indicator of the efficiency of childhood asthma control interventions but rather a holistic approach should be adopted considering the limitations the child suffers as a component of both life and environmental modification in a deliberate attempt to prevent attacks. The ability of the child to function optimally while on treatment should be considered in the treatment impact review.

Constituents of fine particulate matter and asthma in six low- and middle-income countries

BACKGROUND

Evidence concerning the effects of different chemical components of PM_2.5 on asthma is limited, and the methodology to compare the relative importance of different PM_2.5 components is lacking.

OBJECTIVES

To examine the associations between PM_2.5 components and asthma, and investigate which constituent of PM_2.5 possessed the most harmful effect on asthma.

METHODS

A total of 45,690 subjects were surveyed in six countries from 2007 to 2010. We geo-coded the residential community address of the participants, and used satellite remote sensing and chemical transport modeling to estimate their annual average concentrations. Mixed-effects generalized additive models were utilized to examine the associations between PM_2.5 constituents and prevalence of asthma. We further used counterfactual analyses to determine the potential number of asthma cases.

RESULTS

We identified 6,178 asthma cases among the participants, producing a prevalence of 13.5%. The odds ratio (OR) for asthma associated with per standard deviation (SD) increment was 1.12 for PM_2.5 mass, 1.12 for organic carbon (OC), 1.18 for black carbon (BC), 1.19 for sulfate, 1.28 for ammonium, and 1.21 for nitrate after controlling for potential confounders. Our counterfactual analyses suggested that ammonium was responsible for a substantial decline in asthma cases (1382, corresponding to 22.37% of overall cases) if the concentration was reduced to the 5th percentile of the current level.

CONCLUSIONS

Our study suggests that some chemical components (including BC, OC, sulfate, ammonium, and nitrate) of PM_2.5 might be hazardous constituents contributing to the prevalence of asthma, among them, ammonium might be responsible for substantial proportion of asthma cases if reduced to a certain level.