Cross-sectional associations of dietary habits with asthma and wheeze in childhood: confounding for avoidance behaviors

Associations between household airborne culturable fungi and allergies and airway illnesses in childhood in Shanghai, China

Associations of household airborne fungi with allergies in childhood were inconsistent in the epidemiologic studies. During 2013-2014, we conducted a case-control study (phase two), which was nested in a cross-sectional study (phase one) during 2011-2012 in Shanghai, China. We inspected indoor air quality of 454 residences for 5-10 years old children. We defined cases as those children who were reported illnesses in the questionnaire of phase one or phase two and defined controls as those children who were not reported illnesses in both phases. A total of 436 living rooms and 445 bedrooms had valid data of household airborne fungi, and their mean concentrations were 301 cfu/m³ and 310 cfu/m³, respectively. In the multiple logistic regression analyses with adjusting for potential confounders, most associations of 16 studied illnesses with airborne fungi concentration were not statistically significant. Taking children in the 1st quartile that was stratified according to airborne fungi concentration in the living room as reference, only children in the 3rd quartile were significantly associated with a higher odd of lifetime-ever ear infections (adjusted OR, 95% CI 3.05, 1.29-7.21), and children in the 4th quartile were significantly associated with a higher odd of lifetime-ever wheeze (2.72, 1.28-5.75); but children in the 3rd quartile (0.33, 0.17-0.68) and in the 4th quartile (0.47, 0.23-0.97) were significantly associated with a lower odd of rhinitis in the past 12 months prior to the home inspection. Our results indicate that exposures to indoor airborne fungi in low concentrations seemingly have no significant impacts on the risks of most allergic and airway illnesses in childhood. Since families with sick participants might pay more attention to improve indoor air quality, effects of "avoidance behavior" on associations between indoor pollutants and childhood health should be considered in the data analysis and design of the nested case-control study.

The Frequency of Fast Food Consumption in Relation to Wheeze and Asthma Among Adolescents in Gauteng and North West Provinces, South Africa

The prevalence of asthma and allergic diseases have been on the rise, especially in developing countries due to life-style changes. The study aimed to investigate the association between the frequency of fast food consumption with wheeze and asthma among adolescents. A previously validated self-completed questionnaire from the International Study of Asthma and Allergies in Childhood was used to collect information on demographics, socioeconomic status, house characteristics, adolescent respiratory health and diet. The prevalence of wheeze was 38.2% and of asthma was 16.37% among the adolescents. The results from the adjusted regression analyses indicated that eating fast foods three or more times per week was a statistically significant risk factor for wheeze (OR = 1.60; 95% CI: 1.26–2.03) and asthma (OR = 1.37; 95% CI: 1.04–1.91). The study found an association between eating fast foods three or more times per week and wheeze and asthma among adolescents in South Africa. Unhealthy diet plays a crucial role in respiratory health among adolescents; healthy eating habits are encouraged to reduce the burden of respiratory symptoms and diseases.

Household environment, lifestyle behaviors, and dietary habits in relation to childhood atopic eczema in Shanghai, China

PURPOSES

We aim to investigate associations of the child's individual characteristics, building characteristics, home environmental exposures, family lifestyle behaviors, and dietary habits on childhood eczema during lifetime-ever and in the last year before the survey.

METHODS

During April 2011-April 2012, we conducted a cross-sectional study and collected 13,335 parents-reported questionnaires of 4-6-year-old children from 72 kindergartens in Shanghai, China. Logistic regression model was used to investigate associations.

RESULTS

After adjusted for sex, age, family history of atopy, and questionnaire reporter, the factors which were strongly associated (increased odds >30% and p value <0.05) with lifetime-ever eczema included mother employed during pregnancy (adjusted OR 1.33), residence renovated during pregnancy (1.49) and in the child's first year of life (1.31), using laminate (1.58) and solid (1.42) wood as material of floor covering (compared to using cement), residence located in urban district (1.38), and dampness-related exposures in the early residence (mold spots/stains: 1.41; mold odor: 1.41) and in the current residence (water damage: 1.33; damp stains: 1.34; mold spots: 1.32; and windows pane condensation: 1.31). Parental smoking, pet-keeping, and incense-burning had no significant associations with childhood eczema. Similar associations were found for eczema in the last year before the survey. Families with sick children likely changed lifestyle behaviors and dietary habits.

CONCLUSIONS

Childhood eczema could be influenced by many household environmental and non-environmental factors. Exposures during early lifetime likely have greater impact on childhood eczema than current exposures. Associations of lifestyle behaviors and dietary habits with childhood eczema could be modified by family avoidance behaviors.