METHODS: Data from the Isle of Wight birth cohort study (IOW; n = 1,456, aged 18 years) and Kuwait University Allergy cross-sectional study (KUAS; n = 1,154, aged 18-26 years) were analyzed. Acetaminophen use and history of asthma diagnosis and symptoms were self-reported by participants. Sex-stratified associations between acetaminophen use and asthma and statistical interactions were evaluated using Poisson regression with robust variance estimation to infer prevalence ratio. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were estimated.
RESULTS: Current acetaminophen use (at least once in the past month vs. never in the past 12-months) was associated with increased asthma risk in the IOW study (aPR, 1.65, 95% CI: 1.22-2.24) and KUAS (aPR, 1.61, 95% CI: 1.02-2.79). In sex-stratified analysis of the IOW study, acetaminophen use was associated with asthma among males (aPR, 2.35, 95% CI: 1.59-3.47), but not among females (aPR, 1.29, 95% CI: 0.90-1.85; interaction-term p-value = 0.027). Similar results were found in KUAS, with risk seen in males (aPR, 2.58, 95% CI: 1.03-8.38), but not in females (aPR, 1.27, 95% CI: 0.70-2.33; interaction-term p-value = 0.035).
CONCLUSIONS: Acetaminophen appears to be associated with asthma risk in a sex-specific manner with young adult males but not females showing higher risk of this association.