Polymorphism of N-acetyltransferase 2 gene and the susceptibility to alcoholic liver cirrhosis: interaction with smoking

Background: Polymorphism of N-acetyltransferase 2 gene was reported to be associated with the susceptibility of various cancers and liver diseases. However, its relationship to alcoholic liver disease is controversial and open to debate. The aim of this study was to evaluate the relationship of NAT2 genetic polymorphisms and the susceptibility to alcoholic liver cirrhosis (ALC) in Chinese, with special emphasis on the interaction of smoking.

Methods: Peripheral white blood cell DNA from 148 patients with ALC, 104 patients with long-term alcoholic drinking but without cirrhosis (ANC) and 209 healthy controls were genotyped for NAT2 using a polymerase chain reaction-restriction fragment length polymorphism method. The possible confounding factors were included for analysis.

Results: There was no statistical difference in the frequency of NAT2 genotype or NAT2 acetylator status among the 3 groups. However, among the chronic alcoholic drinkers, the rapid acetylators with smoking habits had higher percentage of ALC than those without smoking habit (18.9% vs. 9.5%, p=0.002). The adjusted odds ratio for rapid acetylator smoker to have ALC was 3.45 (95% CI=1.53 to 7.76, p=0.003).

Conclusions: The genetic factor, NAT2 polymorphism, may interact with environmental factor, smoking, to confer different susceptibilities to ALC. NAT2 rapid acetylators with smoking habit may increase the risk of ALC in Chinese.