Early-life exposure to indoor mould and associations with lung function, lung function trajectories and asthma

Indoor mould exposure has detrimental impacts on respiratory symptoms and conditions. There is comparatively little evidence investigating its association with lung function. Maximal lung function in early adulthood is a determinant of morbidity and all-cause mortality. Research has shown early life environmental exposures can affect lung function growth trajectories. Investigate associations between exposure to indoor mould and early life lung function, lung function trajectories, and doctor-diagnosed asthma. Linear, multinomial logistic, and logistic regressions were used to investigate associations with data from the Avon Longitudinal Study of Parents and Children birth cohort study. Lung function analyses were adjusted for height, age, sex, and smoking exposure. Asthma analyses were additionally adjusted for socioeconomic status (SES). Indoor mould exposure at 5 years old was associated with reduced lung function at ages 8 and 15 after adjustment for height, sex, age, and exposure to smoking. At 8, both forced expiratory volume in 1 s (FEV1) (−0.04 l 95%CI −0.08–0.00) and forced vital capacity (FVC) (−0.05 l 95%CI −0.09–0.00) were reduced by 2.4%. At 15, FEV1 reduced by 5.7% (−0.19 l 95%CI −0.32 to −0.06) and FVC by 6.0% (−0.23 l 95%CI −0.37 to −0.08). There was no evidence against the null hypothesis with FEV1 or FVC at 24, FEV1/FVC at any age, or lung function trajectories. There was a strong association with ever having an asthma diagnosis at age 8 years (OR 1.85 95%CI 1.28–2.68), and a weaker association at 24 years (OR 1.67 95%CI 0.94–2.96) after adjustment for height, sex, age, exposure to smoking, and SES. Though this study does not demonstrate an impact of indoor mould exposure on maximal lung function development, it shows strong evidence for an association with a reduced lung function in childhood and adolescence. Further research is needed to determine whether this reflects a vulnerable age, or whether recency to exposure is more important.