High incidence of respiratory disease in Australian infants despite low rate of maternal cigarette smoking

Effects of prenatal alcohol exposure on infant lung function, wheeze, and respiratory infections in Australian children

BACKGROUND

Prenatal alcohol exposure (PAE) is a known risk factor for a range of adverse outcomes, such as facial dysmorphism, adverse birth outcomes, and neurodevelopmental changes. Preclinical research shows that PAE also inhibits lung development, lowers surfactant protein expression, has detrimental effects on alveolar macrophages, and decreases both T and B cell numbers. However, clinical evidence of respiratory impacts from PAE is limited. This study explored whether lung function, wheeze, and incidence of respiratory infections differ in children with PAE compared with unexposed children.

METHODS

Data from the Barwon Infant Study (n = 1074) were examined. PAE data were extracted from maternal questionnaires at trimesters 1 and 2 (combined), and trimester 3, and included as "total standard drinks" during each trimester and total pregnancy intake, a binary yes/no for PAE, and binge drinking (>5 standard drinks in one session). Respiratory outcomes were parent-reported wheeze, lung function (measured by multiple breath washout), and parent report and medical record indicators of health service attendances for respiratory conditions. Linear and logistic regressions were performed to quantify relationships between PAE and respiratory outcomes, controlling for socioeconomic status, birthweight, sex, gestational age, and maternal smoking.

RESULTS

Binge drinking was associated with increased health service attendance for respiratory condition(s) in the first 12 months of life (OR = 5.0, 95% CI (1.7, 20.7), p = 0.008). We did not find a relationship between binary PAE and binge drinking with lung function at 4 weeks of age or wheeze at 12 months. The number of standard drinks consumed in trimester two was associated with a lower lung clearance index (β = -0.011 turnovers, 95% CI (-0.0200, -0.0013), p = 0.03), and a small increase in functional residual capacity (β = 0.34 mL, 95% CI (0.02, 0.66), p = 0.04).

CONCLUSIONS

We found an association between binge drinking and health service utilization for respiratory conditions in infancy, but no evidence that low-level PAE was associated with adverse respiratory outcomes.

Early life infection and proinflammatory, atherogenic metabolomic and lipidomic profiles in infancy: a population-based cohort study

Background:

The risk of adult onset cardiovascular and metabolic (cardiometabolic) disease accrues from early life. Infection is ubiquitous in infancy and induces inflammation, a key cardiometabolic risk factor, but the relationship between infection, inflammation, and metabolic profiles in early childhood remains unexplored. We investigated relationships between infection and plasma metabolomic and lipidomic profiles at age 6 and 12 months, and mediation of these associations by inflammation.

Methods:

Matched infection, metabolomics, and lipidomics data were generated from 555 infants in a pre-birth longitudinal cohort. Infection data from birth to 12 months were parent-reported (total infections at age 1, 3, 6, 9, and 12 months), inflammation markers (high-sensitivity C-reactive protein [hsCRP]; glycoprotein acetyls [GlycA]) were quantified at 12 months. Metabolic profiles were 12-month plasma nuclear magnetic resonance metabolomics (228 metabolites) and liquid chromatography/mass spectrometry lipidomics (776 lipids). Associations were evaluated with multivariable linear regression models. In secondary analyses, corresponding inflammation and metabolic data from birth (serum) and 6-month (plasma) time points were used.

Results:

At 12 months, more frequent infant infections were associated with adverse metabolomic (elevated inflammation markers, triglycerides and phenylalanine, and lower high-density lipoprotein [HDL] cholesterol and apolipoprotein A1) and lipidomic profiles (elevated phosphatidylethanolamines and lower trihexosylceramides, dehydrocholesteryl esters, and plasmalogens). Similar, more marked, profiles were observed with higher GlycA, but not hsCRP. GlycA mediated a substantial proportion of the relationship between infection and metabolome/lipidome, with hsCRP generally mediating a lower proportion. Analogous relationships were observed between infection and 6-month inflammation, HDL cholesterol, and apolipoprotein A1.

Conclusions:

Infants with a greater infection burden in the first year of life had proinflammatory and proatherogenic plasma metabolomic/lipidomic profiles at 12 months of age that in adults are indicative of heightened risk of cardiovascular disease, obesity, and type 2 diabetes. These findings suggest potentially modifiable pathways linking early life infection and inflammation with subsequent cardiometabolic risk.

Funding:

The establishment work and infrastructure for the BIS was provided by the Murdoch Children’s Research Institute (MCRI), Deakin University, and Barwon Health. Subsequent funding was secured from National Health and Medical Research Council of Australia (NHMRC), The Shepherd Foundation, The Jack Brockhoff Foundation, the Scobie & Claire McKinnon Trust, the Shane O’Brien Memorial Asthma Foundation, the Our Women’s Our Children’s Fund Raising Committee Barwon Health, the Rotary Club of Geelong, the Minderoo Foundation, the Ilhan Food Allergy Foundation, GMHBA, Vanguard Investments Australia Ltd, and the Percy Baxter Charitable Trust, Perpetual Trustees. In-kind support was provided by the Cotton On Foundation and CreativeForce. The study sponsors were not involved in the collection, analysis, and interpretation of data; writing of the report; or the decision to submit the report for publication. Research at MCRI is supported by the Victorian Government’s Operational Infrastructure Support Program. This work was also supported by NHMRC Senior Research Fellowships to ALP (1008396); DB (1064629); and RS (1045161) , NHMRC Investigator Grants to ALP (1110200) and DB (1175744), NHMRC-A*STAR project grant (1149047). TM is supported by an MCRI ECR Fellowship. SB is supported by the Dutch Research Council (452173113).

Are wheezing, asthma and eczema in children associated with mother's health during pregnancy? Evidence from an Australian birth cohort

BACKGROUND

This study investigated the prevalence of wheezing, asthma, and eczema among Australian children using longitudinal data from birth to 15 years of age. This study also examined the association between maternal health status during pregnancy and their offspring's respiratory and allergic morbidities using sex-segregated data.

METHODS

This study used data from the Longitudinal Study of Australian Children (LSAC) where approximately 5000 children of a birth cohort across Australia were surveyed in 2004. These children were followed biennially in eight waves up to their age of 15 years until 2018. The status of the children's wheezing, asthma, and eczema were reported by the mothers upon doctors' diagnosis (for asthma) or self-assessment (for wheezing or eczema). Binomial logistic regression models were used to analyse associations between maternal health during pregnancy and their children's health outcomes.

RESULTS

Asthma prevalence among 0-1-year aged children was 11.7%, increased to 15.4% when the children were 10-11 years old, and then decreased to 13.6% when they were 14-15 years old. Wheezing and eczema were most prevalent when the children were 2-3 years old (26.0 and 17.8% respectively) and were least prevalent when the children were 14-15 years old (7.3 and 9.5% respectively). Maternal asthma, smoking during pregnancy, and pre-pregnancy obesity were significantly associated with an increased risk of wheezing and asthma in Australian children. Childhood eczema was associated only with maternal asthma. These associations were stronger among male children up to age 10-11 and during adolescence (12-15 years of age), female children were more prone to wheezing, asthma, and eczema.

CONCLUSION

This is a comprehensive longitudinal study of Australian children (0-15 years of age) to assess the prevalence (with sex-specific differences) of wheezing, asthma and eczema as well as the association between these respiratory and allergic morbidities and maternal health during pregnancy. The study findings suggest that careful medical and obstetric monitoring, improved specific age-sex wise risk factor prevention for children and health promotion for pregnant women would help protect child health.

Prevalence and associated factors of wheeze in early infancy

BACKGROUND

The aim of this study was to assess the prevalence of wheeze in early childhood and to characterize associated factors for wheeze that could identify potentially feasible interventions for the future prevention of wheeze.

METHODS

We performed a cross-sectional analysis of the data from the International Study of Asthma and Allergies in Childhood (ISAAC)-modified self-administered questionnaire of parents of 4-month-old infants at well-child visits (mandatory health check-ups) in Nagoya City, Japan, between April 2016 and March 2017 (development dataset) and between April 2017 and March 2018 (validation dataset). We used a multivariable, multilevel analysis to identify significant (P < 0.05), associated factors (Bonferroni correction was applied as necessary) after adjustment for local outbreaks of virus-transmitted diseases, access to medical facilities, and socioeconomic status.

RESULTS

Among the 20 362 questionnaires given to families of infants living in Nagoya City (development dataset), 19 104 questionnaires (93.8%) were analyzed after data cleaning. In all, 1,446 (7.6%) infants experienced wheeze at least once within 4 months of age, 991 (5.2%) visited the clinic/hospital with wheeze, and 244 (1.3%) underwent hospitalization at that time. In the multilevel, multivariable model for hospitalization with wheeze, significant associated factors were male sex (adjusted odds ratio 1.8; 95% confidence interval 1.4-2.3), maternal current smoking (3.3; 2.0-5.5), and having at least one sibling (3.0; 2.2-4.1). These factors were also associated with wheeze and clinic/hospital visit with wheeze, and the results were confirmed in the validation dataset.

CONCLUSIONS

Our study highlights that smoking cessation among mothers and improved hand hygiene at home are two interventions that could potentially decrease wheeze in early infancy.

Burden of infection in Australian infants

AIM

To determine the incidence, risk factors and health service utilisation for infection in the first 12 months of life in a population-derived Australian pre-birth cohort.

METHODS

The Barwon Infant Study is a population-derived pre-birth cohort with antenatal recruitment (n = 1074) based in Geelong, Victoria, Australia. Infection data were collected by parent report, and general practitioner and hospital records at 1, 3, 6, 9 and 12 months of age. We calculated the incidence of infection, attendance at a health service with infection and used multiple negative binomial regression to investigate the effects of a range of exposures on incidence of infection.

RESULTS

In the first 12 months of life, infections of the upper and lower respiratory tract (henceforth 'respiratory infections'), conjunctivitis and gastroenteritis occurred at a rate of 0.35, 0.04 and 0.04 episodes per child-month, respectively. A total of 482 (72.4%) infants attended a general practitioner with an infection and 69 (10.4%) infants attended the emergency department. Maternal antibiotic exposure in pregnancy and having older siblings were associated with respiratory infection. Childcare attendance by 12 months of age was associated with respiratory infections and gastroenteritis. Breastfeeding, even if less than 4 weeks in total, was associated with reduced respiratory infection.

CONCLUSION

Infection, especially of the respiratory tract, is a common cause of morbidity in Australian infants. Several potentially modifiable risk factors were identified, particularly for respiratory infections. Most infections were managed by general practitioners and 1 in 10 infants attended an emergency department with infection in the first year of life.

Association between active tobacco use during pregnancy and infant respiratory health: a systematic review and meta-analysis

OBJECTIVE

To evaluate what is known about active tobacco use during pregnancy and the association with infant respiratory health.

DESIGN

Systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

DATA SOURCES

MEDLINE, EMBASE, Cochrane, CINAHL, and Maternity and Infant Care were searched thoroughly until June 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included case-control and cohort studies estimating the association between active tobacco use during pregnancy and infant respiratory health (wheezing and apnoea) and lung function parameters in the first 12 months of life.

DATA EXTRACTION AND SYNTHESIS

Extraction and risk of bias assessment were conducted by two independent reviewers. The odds ratio, relative risk and mean differences were pooled with a 95% CI using the generic inverse variance method. Heterogeneity was assessed and expressed by percentage using I2.

RESULTS

We identified 4423 abstracts, and 21 publications met the eligibility criteria. Pooled OR showed an increase in wheezing episodes in infants born to mothers who were active tobacco users during pregnancy (OR 1.50, 95% CI 1.27 to 1.77, p<0.01). Mixed results were found on lung function parameters, and a meta-analysis including two studies with comparable methodology showed a trend towards reduced maximum flow rate at functional residual capacity of -34.59 mL/s (95% CI -72.81 to 3.63, p=0.08) in 1-month-old infants born to women who smoked during pregnancy. A higher risk of apnoea was described for infants born to mothers who used smokeless tobacco during pregnancy, while the results in infants born to women who actively smoked tobacco during pregnancy were non-conclusive.

CONCLUSION

Infants born to mothers who actively smoked during pregnancy are at higher odds of having wheeze and may have lower lung function. Smokeless tobacco use in pregnancy may increase the risk of apnoea in infancy.

PROSPERO REGISTRATION NUMBER

CRD42018083936.