Association between prenatal or postpartum exposure to tobacco smoking and allergic rhinitis in the offspring: An updated meta-analysis of nine cohort studies

A review of common influencing factors and possible mechanisms associated with allergic diseases complicating tic disorders in children

Over the past few decades, the incidence of childhood allergic diseases has increased globally, and their impact on the affected child extends beyond the allergy itself. There is evidence of an association between childhood allergic diseases and the development of neurological disorders. Several studies have shown a correlation between allergic diseases and tic disorders (TD), and allergic diseases may be an important risk factor for TD. Possible factors influencing the development of these disorders include neurotransmitter imbalance, maternal anxiety or depression, gut microbial disorders, sleep disturbances, maternal allergic status, exposure to tobacco, and environmental factors. Moreover, gut microbial disturbances, altered immunological profiles, and DNA methylation in patients with allergic diseases may be potential mechanisms contributing to the development of TD. An in-depth investigation of the relationship between allergic diseases and TD in children will be important for preventing and treating TD.

Childhood atopic disorders in relation to placental changes-A systematic review and meta-analysis

Fetal programming may arise from prenatal exposure and increase the risk of diseases later in life, potentially mediated by the placenta. The objective of this systematic review was to summarize and critically evaluate publications describing associations between human placental changes and risk of atopic disorders during childhood. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The inclusion criteria were original research articles or case reports written in English describing a human placental change in relation to disease occurring in offspring during childhood. The MEDLINE and EMBASE databases were searched for eligible studies. Risk of bias (RoB) was assessed using the ROBINS-I tool. The results were pooled both in a narrative way and by a meta-analysis. Nineteen studies were included (n = 12,997 participants). All studies had an overall serious RoB, and publication bias could not be completely ruled out. However, five studies showed that histological chorioamnionitis in preterm-born children was associated with asthma-related problems (pooled odds ratio = 3.25 (95% confidence interval = 2.22-4.75)). In term-born children, a large placenta (≥750 g) increased the risk of being prescribed anti-asthma medications during the first year of life. Placental histone acetylation, DNA methylation, and gene expression differences were found to be associated with different atopic disorders in term-born children. There is some evidence supporting the idea that the placenta can mediate an increased risk of atopic disorders in children. However, further studies are needed to validate the findings, properly control for confounders, and examine potential mechanisms.

Maternal smoking around birth and its influence on offspring allergic diseases: A mendelian randomization study

Objective

The influence of maternal smoking around birth (MSAB) on offspring allergic diseases, specifically childhood asthma (CA), allergic rhinitis (AR), allergic conjunctivitis (AC), and atopic dermatitis (AD) remains incompletely understood. We performed a rigorous mendelian randomization (MR) study to obtain the unconfounded association between MSAB and allergic diseases in offspring with and without adjustment for the effect of breastfeeding.

Methods

Utilizing publicly available information of MSAB, breastfeeding, CA, AR, AC, and AD from large-scale genome-wide association studies (GWAS), we performed a two-sample mendelian randomization (TSMR) analysis to assess the respective causal relationship of MSAB and breastfeeding to allergic diseases in offspring. To get a reliable conclusion, MR Egger regression, weighted median, and inverse variance weighted (IVW) were employed to estimate the causality, with IVW as the primary analysis. Multivariate MR (MVMR) analysis was used to assess the effect of MSAB on allergic diseases after adjusting for breastfeeding's impact. Sensitivity analysis was conducted using the Cochran Q test, MR-Egger, and leave-one-out approaches to ensure the reliability and stability of results.

Results

The TSMR analysis demonstrated MSAB increased the risks of CA (PIVW = 0.013, OR: 1.018, 95%CI: 1.004 to 1.033) and AD (PIVW = 0.006, OR: 8.293, 95%CI: 1.815 to 37.884) in offspring. Conversely, breastfeeding decreased the risk of CA (PIVW <0.001, OR: 0.946, 95%CI: 0.918 to 0.974). MSAB still increased the risks of CA (P = 0.0497, OR: 1.013, 95%CI: 1.000017 to 1.026) and AD (P = 0.003, OR: 13.800, 95%CI: 2.490 to 269.246) after adjusting for breastfeeding. We observed no strong indication of a negative causality between MSAB and AC and AR.

Conclusion

Our findings provided robust evidence of the adverse effects of MSAB on offspring. We emphasized the urgency of smoking cessation around birth and the importance of breastfeeding even in smoking mothers.

Environmental Risk Factors, Protective Factors, and Biomarkers for Allergic Rhinitis: A Systematic Umbrella Review of the Evidence

Many potential environmental risk factors, protective factors, and biomarkers of AR have been published, but so far, the strength and consistency of their evidence are unclear. We conducted a comprehensive review of environmental risk, protective factors, and biomarkers for AR to establish the evidence hierarchy. We systematically searched Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to December 31, 2022. We calculated summary effect estimate (odds ratio (OR), relative risk (RR), hazard ratio (HR), and standardized mean difference (SMD)), 95% confidence interval, random effects p value, I2 statistic, 95% prediction interval, small study effects, and excess significance biases, and stratification of the level of evidence. Methodological quality was assessed by AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). We retrieved 4478 articles, of which 43 met the inclusion criteria. The 43 eligible articles identified 31 potential environmental risk factors (10,806,206 total population, two study not reported), 11 potential environmental protective factors (823,883 total population), and 34 potential biomarkers (158,716 total population) for meta-analyses. The credibility of evidence was convincing (class I) for tic disorders (OR = 2.89, 95% CI 2.11-3.95); and highly suggestive (class II) for early-life antibiotic use (OR = 3.73, 95% CI 3.06-4.55), exposure to indoor dampness (OR = 1.49, 95% CI 1.27-1.75), acetaminophen exposure (OR = 1.54, 95% CI 1.41-1.69), childhood acid suppressant use (OR = 1.40, 95% CI 1.23-1.59), exposure to indoor mold (OR = 1.66, 95% CI 1.26-2.18), coronavirus disease 2019 (OR = 0.11, 95% CI 0.06-0.22), and prolonged breastfeeding (OR = 0.72, 95% CI 0.65-0.79). This study is registered in PROSPERO (CRD42022384320).