Investigation of the Association between Adult Wheeze and Household Beta(1→3)-glucan Exposures in First Nations Communities in Canada

Abstract

TPS 752: Respiratory effects and allergies, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Background: In Canada, damp housing conditions in First Nations communities continues to be a major concern for respiratory health. In this context, no studies have reported the role of household beta glucans. We examined the association between β(1→3)-glucans in household dust and reports of wheeze. Methods: As part of the First Nations Longitudinal Respiratory Health Study initiated in 2012, participating adults who completed a respiratory and environmental questionnaire volunteered to partake in a home environmental assessment that included collection of settled dust for β(1→3)-glucan analysis. Information was obtained about housing conditions including water leaks/floods and subsequent damage in the past 12 months, mold or mildew odor and visible signs of mold. Dust samples were collected from floors of common living areas following the International Study of Asthma and Allergy in Children (ISAAC) protocol. Prior to laboratory analysis, dust was sieved and stored at -20°C. Analysis for β(1→3)-glucan was performed using Glucatell assay according to manufacturer’s specifications. Wheeze was defined as any wheeze without colds or wheezing most days or nights. Logistic regression with generalized estimating equations were used to examine associations between wheeze and β(1→3)-glucan (log transformed) adjusting for current smoking, damp housing, mildew odor, pets, age and sex. Results: Of the 874 participants, there were 317 adults living in 144 homes who participated in the home assessments. Of these, 293 adults had valid household β(1→3)-glucan results. The prevalence of wheeze was 47.0%. The mean (standard deviation) levels of soluble β(1→3)-glucan were 33.1(22.76) pg/mL. While reports of damp housing were associated with increased wheeze (p< 0.05), higher β(1→3)-glucan levels in the home were associated with lower wheeze (p < 0.05). Conclusion: The inverse association between household beta glucans levels and wheeze found in this study adds to the controversy regarding the varying role of β(1→3)-glucans for human respiratory health.