Exposure to dogs and cats and risk of asthma: A retrospective study

Pets and related allergens modify the association between early life DEHP exposure and respiratory outcomes in children

INTRODUCTION

Throughout the perinatal period children are exposed to complex mixtures, including indoor chemicals such as phthalates, and biological agents. However, few studies focus on interactions between early-life co-exposures to shed light on how co-exposures modify their individual effects. Therefore, our study aims to assess whether early-life exposure to pets and related biological agents, namely pet allergens and endotoxin, modifies the association between di-(2-ethylhexyl) phthalate (DEHP) and asthma and wheeze in preschoolers to gain insight into interactions.

METHODS

Using data from a Canadian birth cohort study (CHILD), we conducted two complementary analyses on respiratory outcomes. First, we combined pet ownership with DEHP measurements from house dust (N = 726). Second, we focused on a subgroup of children with exposure measurements of both DEHP and biological agents in dust (N = 261). We used multivariable logistic regression models to assess whether pets and quantified biological agent levels modify associations between DEHP and asthma at 5 years and recurrent wheeze between 2 and 5 years. Interaction terms were included in the models and stratified analyses were further conducted.

RESULTS

Associations between DEHP and asthma and wheeze were modified by pet ownership and related biological agents. For persistent/recurrent wheeze, the association with DEHP became larger among children with dogs at home and with higher dog allergens (p-interaction <0.1) and became smaller and insignificant when exposed to cats. Similarly, for asthma, the association with DEHP tended to be larger among children with dogs (also higher dog allergens) and among children without cats (also lower cat allergens) at home, respectively. Endotoxin levels modified the association between DEHP and persistent wheeze (p-interaction <0.1).

CONCLUSIONS

Early-life exposure to pets and related biological agents may modify the associations between phthalates and asthma and wheeze in children. Heterogeneity in single exposure studies could be a result of differences in co-exposures among studies.

Determinants of asthma among adults in Tigray, Northern Ethiopia: a facility-based case-control study

Background

Asthma is a public health concern affecting millions of productive age groups. Several studies were conducted on the determinants of asthma in children. However, little is known about the determinants of asthma among adults in Ethiopia. Understanding the determinants of asthma among adults can help reduce its burden. This study was aimed at identifying determinant factors for developing asthma among adults in Tigray hospitals.

Methods

A facility-based, unmatched case-control study design was conducted from January 1 to April 26, 2019. A total of 698 participants (228 cases and 470 controls) completed their guided interviews using structured and pretested questionnaires by trained data collectors. A modified standard questionnaire from the European Community Respiratory Health Survey II (ECRHS II) was used to collect the data. The case definition was patients having asthma, and the control definition was patients without asthma. Data were entered and cleaned using Epi Data Manager Version 3.1 software and imported to statistical packages for social sciences Version 25 software for analysis. To identify asthma determinants, bivariate and multivariable logistic regression models were fitted.

Results

The response rate for both cases and controls was 95.9%. The odds of developing asthma was nearly twice higher among those who resided in urban (AOR = 1.68; 95% CI [1.13-2.50]), more than twice higher among those who have income less than 1000 ETB (AOR = 2.3; 95% CI [1.17-4.56]), twice higher among those who had history of skin allergy (AOR = 2.09; 95% CI [1.14-3.86]), over four times higher among those with family history of asthma (AOR = 4.26; 95% CI [2.63-6.91]), three times higher among those having house dust or smoke exposure (AOR = 3.01; 95% CI [1.96-4.64]), over five times higher among those lifetime firewood users (AOR = 5.39; 95% CI [3.34-8.72]), door opening while cooking (AOR = 0.35; 95% CI [0.26-0.55]), nearly two times higher among those having house dampness (AOR = 1.98; 95% CI [1.069-3.68]), over seven times higher among pet owners (AOR = 7.46; 95% CI [4.04-13] and almost twice higher among those who were physically inactive (AOR = 1.75; 95% CI [1.11-2.85]).

Conclusion

Asthma has been associated with urbanization, low income, a history of allergic diseases, indoor smoke or dust, firewood use, pet ownership, and a sedentary lifestyle. The community should be informed about the known risks and implement preventive steps like opening a door while cooking to lower the risk of asthma.

The Association between Vitamin D, Interleukin-4, and Interleukin-10 Levels and CD23+ Expression with Bronchial Asthma in Stunted Children

Children with stunted growth have an increased risk of wheezing, and studies have shown that low levels of vitamin D and interleukin (IL)-10, along with increased IL-4 levels and CD23+ expression, are present in stunted and asthmatic children. To date, it is not known whether these factors are related to the incidence of asthma in stunted children. This case-control study investigated the association between vitamin D, IL-4, and IL-10 levels and CD23+ expression with bronchial asthma in stunted children. The study included 99 children aged 24-59 months, i.e., 37 stunted-sthmatic children (cases), 38 stunted children without asthma, and 24 non-stunted children with asthma. All children were tested for their 25(OH)D levels using chemiluminescent immunoassay (CLIA), IL-4 and IL-10 levels were measured through enzyme-linked immunosorbent assay (ELISA) testing, and CD23+ expression was measured through flow cytometry bead testing. The data were analyzed using chi-squared, Kruskal-Wallis, and Mann-Whitney tests. The results showed that stunted asthmatic children had a higher incidence of atopic family members than those without asthma. Additionally, stunted asthmatic children had a higher prevalence of vitamin D deficiency (48.6%) than the control group (44.7% and 20.8%). Furthermore, stunted asthmatic children had significantly lower levels of 25(OH)D [20.55 (16.18-25.55), p = 0.042] and higher levels of IL-4 [1.41 (0.95-2.40), p = 0.038], although there were no significant differences in IL-10 levels and CD23+ expression. The study concluded that low vitamin D and high IL-4 levels are associated with bronchial asthma in stunted children, while IL-10 and CD23+ do not show a significant association.