African biogeographical ancestry, atopic and non-atopic asthma and atopy: A study in Latin American children

BACKGROUND

Genetic variants underlying African ancestry have been suggested be implicated in the ethnic-racial inequalities reported for asthma and allergies.

OBJECTIVES

To investigate the association between individual African ancestry and asthma symptoms, atopic and non-atopic asthma, and atopy in children.

METHODS

A cross-sectional study encompassing 1190 individuals was conducted. African biogeographic ancestry was estimated using 370 539 genome-wide SNPs. Serum levels of specific IgE were measured, and skin prick test (SPT) performed for the most common local aeroallergens. Information on asthma symptoms was obtained by applying the International Study of Allergy and Asthma in Childhood questionnaire. The associations between the proportion of individual African ancestry and the outcomes investigated were analyzed through multivariate models adjusted for socio-environmental variables, infections markers, and psychosocial factors.

RESULTS

Each 20% increase in the proportion of African ancestry was negatively associated with SPT reactivity (OR: 0.79, 95%CI: 0.66-0.96) and positively associated with asthma symptoms in non-atopic individuals (OR: 1.40, 95%CI: 1.03-1.89). We estimated that socioeconomic status and number of infections mediated 28.4% of the effect of African ancestry on SPT reactivity, while 20.2% of the effect on non-atopic asthma was explained by socioeconomic status and behavioral problems in children.

CONCLUSIONS

The negative association observed between African ancestry and atopy is most probably explained by unobserved environmental or social factors that covariate with ancestry. For non-atopic asthma, in turn, putative genetic variants of risk underlying African ancestry may play some role.

Screening for common mental disorders using the SRQ-20 in Brazil: what are the alternative strategies for analysis?

Objective:

To analyze the prevalence of common mental disorders (CMD) assessed with the Self Reporting Questionnaire (SRQ-20), using the established cutoff point, and comparing it with the results of a joint correspondence factor analysis (CFA) and cluster analysis and of a latent class analysis (LCA).

Methods:

A cross-sectional study was carried out in an urban sample of 1,095 women aged 19 to 55 years. Joint CFA-cluster analysis and LCA were used.

Results:

We found a high prevalence of CMD, regardless of classification method (37.6% when using the cutoff point; 44.4% and 52% for LCA and joint CFA-cluster, respectively). The alternative analysis strategies describe the cases more efficiently when compared to the traditional cutoff method, especially regarding more severe symptoms. Both alternative strategies also provide a description of the SRQ-20 dimensions in their particularities, which may be useful for the planning and implementation of specific actions in a given population.

Conclusion:

The SRQ-20 cutoff point seems to underestimate the magnitude of CMD among women. The alternative methods of analysis presented herein highlight the different possibilities of using this important instrument of screening for mental health.

Prevalence of behavior problems and associated factors in preschool children from the city of Salvador, state of Bahia, Brazil

Objective:

To identify the prevalence of internalizing and externalizing behavior problems among preschoolers from the city of Salvador, state of Bahia, Brazil, and their associations with maternal mental health and family characteristics.

Methods:

This was a cross-sectional study of 349 children aged 49 to 72 months, randomly selected from 20,000 households representing the range of socioeconomic and environmental conditions in Salvador. In 1999, we assessed sociodemographic variables and family environment characteristics. In 2001, we used the Child Behavior Checklist to measure and describe the frequencies of behavior problems. We conducted bivariate and multivariate analysis to estimate associations between family and maternal factors and prevalence of behavior problems.

Results:

The overall prevalence of behavior problems was 23.5%. The prevalence of internalizing problems was 9.7%, and that of externalizing problems, 25.2%. Behavior problems were associated with several maternal mental health variables, namely: presence of at least one psychiatric diagnosis (odds radio [OR] 3.01, 95%CI 1.75-5.18), anxiety disorder (OR 2.06, 95%CI 1.20-3.46), affective disorder (OR 2.10, 95%CI 1.21-3.65), and mental health disorders due to use of psychoactive substances (OR 2.31, 95%CI 1.18-4.55).

Conclusion:

The observed prevalence of child behavior problems fell within the range reported in previous studies. Maternal mental health is an important risk factor for behavior problems in preschool-aged children.