地方性砷中毒发病危险因素的病例对照研究

目的探讨地方性砷中毒（地砷病）的发病危险因素，评估p16甲基化在地砷病发病中的作用。方法采用两项1：1配对病例对照研究方法，40例病例选自病区确诊的地砷病患者，对照分别选自病区和非病区各40例健康人；采用标准化问卷进行调查，获取病例和对照组的有关暴露因素：采用甲基化特异性PCR（MS—PCR）技术，测定血样p16基因甲基化水平；并用条件logistic回归分析方法处理资料。结果病例与病区对照组分析结果表明，饮水含砷量（OR=4．2，P〈0．01）和饮水年限（OR=1．192．P〈0．05）对地砷病发病的影响有统计学意义。p16甲基化测定结果表明，病例组与非病区对照组比较，对地砷病发病的影响有非常显著的统计学意义（OR=10．0，P〈0．01）。结论饮水含砷量、饮水年限和p16基因甲基化可能都是地砷病发病的危险因素；但是，p16基因甲基化可能是地砷病发病的重要危险因素之一，这对阐明地砷病的病因和发病机制有着重要的理论意义。

A case-control studies on the risk factors of endemic arsenism

Objective To evaluate the roles of pl6 gene methylation in occurrence of endemic arsenism and the risk factors. Methods Two 1 :1 pair-matched case-control studies were conducted in 40 typical and definitely diagnosed patients with endemic arsenism, 40 controls selected from prevailing areas and another 40 controls from non-prevailing areas, respectively. According to a standardized structured questionnaire, the patients and the controls were interviewed for information on risk factors. Methylation of p16 gene in the blood specimens were analyzed for all the subjects using MS-PCR techniques. Risk factors for endemic arsenism were analyzed with conditional logistic regression model. Results The concentration of arsenic in drinking water(OR= 4.2, P < 0.01) and years drinking the water (OR = 1.192, P < 0.05) were significantly associated with the prevalence of endemic arsenism. In non-prevaling areas, hypermethylation of pl6 gene (OR = 10.0, P < 0.01) was significantly associated with the prevalence of endemic arsenism. Conclusions Factors as concentration of arsenic in the drinking water, years drinking the water, hypermethylation of p16 gene in the blood specimens, seem to be three risk factors of endemic arsenism, but the hypermethylation of p16 gene is one of the most important risk factors, which is important to elucidate the mechanism for endemic arsenism.