Betel nut chewing as a risk factor for hepatitis C infection in Taiwan--a community-based study.

To the Editor: We completed a comprehensive health survey and structural questionnaires among the adults living in the eastern area of Taichung City, Taiwan, including the anti–hepatitis C (anti-HCV) antibody status and the components of metabolic syndrome, from 2004 to 2005. A total of 1045 adults were enrolled in this study. The anti-HCV seropositive (anti-HCV+) prevalence was 6.6% (69/1045). Results were expressed as mean (standard deviation). A P value <.05 was considered statistically significant. Multivariate logistic regression analyses were conducted to explore the factors that were independently associated with anti-HCV. The strength of association was presented as odds ratio (OR) with 95% confidence intervals (CIs) and P values. Table 1 shows the basic characteristics of all subjects. The anti-HCV+ subjects had higher alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and were more elderly than the anti-HCV– subjects. In addition, levels of triglycerides were significantly lower in the anti-HCV+ subjects compared with the anti-HCV– subjects (P<.01). There were no significant differences between anti-HCV+ and anti-HCV– subjects in terms of gender, body mass index (BMI), high-density lipoprotein cholesterol (HDL-C) levels, systolic and diastolic blood pressures and fasting plasma glucose. Multivariate logistic regression analyses were conducted to clarify the independent factors associated with anti-HCV. Variables included age, sex, smoking, drinking, betel nut chewing, exercise, milk drinking, and the presence of hypertension, diabetes mellitus and hyperlipidemia. Betel nut chewing was significantly associated with anti-HCV+ as was milk drinking (Table 2 crude odds ratio). After being adjusted for appropriated covariates, betel nut chewing was still significantly associated with anti-HCV+ (Table 2adjusted odds ratio). Chronic HCV infections are the major etiologies of hepatocellular carcinoma (HCC) in Taiwan.1 The prevalence of anti-HCV (6.6%) in our study was higher than that in community controls.2 The variation in crude HCV seroprevalence ranged from 0.4% to 10.5%, and HCV infection takes two to four decades to lead to HCC.3 The habit of betel nut chewing is prevalent among men in Taiwan. It is especially prevalent among blue-collar workers, less educated men, cigarette smokers and alcohol drinkers.4 The population of betel nut chewers has increased gradually. Recently, the habit of betel nut chewing was found to be a risk factor for HCC, and an increased HCC risk is associated with seropositivity of anti-HCV in Taiwan.5 This information indirectly supports our finding that betel nut chewing is an independent risk factor for anti-HCV. Chronic hepatitis C and betel nut chewing are still a major public health concern in Taiwan. Although the precise mechanism for the association between betel nut chewing and anti-HCV remains to be determined, this study suggests that abstention from betel nut chewing is important for the prevention of chronic hepatitis C.

Table 1

Basic characteristics of anti-HCV seropositive and seronegative subjects.

Table 2

Multivariate logistic regression analyses of variables associated with anti-HCV.