Abstract:
Background:
An increase in body mass index (BMI) z-score and an unhealthy diet rich in sugar are known
to be positively associated with asthma incidence. The link between scabies and asthma has
never been investigated before.
Aim:
I explored the relationship between BMI z-score, diet, and the incidence of asthma. The link
between scabies and asthma was also investigated.
Design:
I conducted a study of 6,854 children participating in the “Growing Up in New Zealand”
cohort. Exposures were BMI z-score at two, 54 months, eight years, and dietary intake
information collected using a food frequency questionnaire administered when the children
were two years and 54 months old. Scabies diagnosis was derived from either hospital
diagnosis or prescription for permethrin. Outcomes were diagnosis of “current” and “severe”
asthma according to the International Study of Asthma and Allergies in Childhood (ISAAC)
parental questionnaire when children were eight years old. Food frequency questionnaire
information was summarised into two principal components. Potential confounding factors,
including gender, ethnicity, socioeconomic status, house dampness and mound, maternal
smoking and breastfeeding, were included in the analysis.
Results:
The prevalence of current and severe asthma was respectively 10.9% (745/6,854) and 3.0%
(4,665/6,854), with 28.9% (1982/6,854) of missing data. The diagnosis of these conditions was
more likely in boys, Māori children, and children living in the most deprived areas. Current
asthma was also more likely in Pacific children. There is also a strong association between
mothers who reported smoking cigarettes and both conditions.
