Aldehyde dehydrogenase 2-a potential genetic risk factor for lung function among southern Chinese: Evidence from the Guangzhou Biobank Cohort Study

Purpose: In Asia, moderate alcohol users have better lung function. Never users have more inactive aldehyde dehydrogenase 2 (ALDH2) alleles (A) potentially generating confounding because inactive alleles may increase acetaldehyde exposure and reduce lung function. Methods: We examined the association of ALDH2 genotypes with percentage predicted lung function (forced expiratory volume in 1second; forced vital capacity) for age, sex, and height among 5641 older Chinese using multivariable linear regression. Results: ALDH2 genotypes were associated with alcohol use and height but not other attributes. Inactive alleles were inversely associated with lung function (percentage predicted forced expiratory volume in 1second-1.52%, 95% confidence interval [CI],-2.52% to-0.51% for one inactive allele and-2.05%, 95% CI,-3.85% to-0.26% for two inactive alleles compared with two active alleles; and for percentage predicted forced vital capacity-1.25%, 95% CI-2.15% to-0.35% and-1.65%, 95% CI,-3.25% to-0.04%). The association of moderate use with lung function was attenuated after adjusting for ALDH2, in addition to other potential confounders. Conclusions: Previous findings in Chinese may be confounded by ALDH2. High frequency of inactive ALDH2 alleles in East Asia may exacerbate the effect of environmental acetaldehyde exposure on lung function and potentially on chronic obstructive pulmonary disease.