南方食管癌高低发区人群尿总N-亚硝基化合物与N-亚硝基氨基酸关系研究

Association between the excretion levels of urinary TNOC and NAAs in the inhabitants of high and low risk area for esophageal cancer in southern China

为了解尿总亚硝基化合物指标在南方食管癌亚硝胺病因研究中的作用 ,探讨该指标与传统亚硝基氨基酸指标的关系。在南方食管高发区南澳县和低发区陆丰县各随机选择 1 2 0名 35～ 64岁健康男性 ,收集1 2小时尿液测定总N 亚硝基化合物 (TNOC)水平和 4种N 亚硝基氨基酸 (NAAs)含量。结果表明 ,尿中总N 亚硝基化合物含量与南方食管癌死亡率呈正相关关系 (rs=0 2 5 ,P <0 0 5)。食管癌高发区人群尿中总N 亚硝基化合物仅有 7 5 %来自 4种N 亚硝基氨基酸。低发区人群尿总N 亚硝基化合物中 4种N 亚硝基氨基酸占了 57%。南方食管癌高发区人群尿样中亚硝胺成份较低发区复杂。尿总亚硝基化合物指标是评价人体亚硝胺接触水平的良好指标 ,可用于食管癌亚硝胺病因研究。当尿中亚硝胺种类较少时 ,总亚硝基化合物指标与亚硝基氨基酸指标才有相关性。

To assess the role of urinary total N nitroso compounds(TNOC) index in study etiology of N nitroso compounds(NOC) of esophageal cancer in southern China and to study the association between TNOC index and traditional indexes of N nitrosamino acids(NAAs). The samples of 12 hr overnight urine were collected from 120 male adults in high risk area (Nanao county) and low risk area(Lufeng county) for esophageal cancer. The 240 male healthy subjects(35-64 years old) were selected by a 3 stage random cluster sample procedure. Levels of TNOC and 4 categories of NAAs were measured in samples. The results showed that Urinary TNOC contents were positively correlated with esophageal cancer mortality in the south( r s=0 25, P< 0 05). Only 7 5% content of urinary TNOC came from the 4 categories of NAAs in the high risk area when 57% content of urinary TNOC came from the NAAs in the low risk area. The urinary NOC components in the high risk area were more complex than the components in the low risk area. Urinary TNOC is a better index that is applied to assess the exposure dose of TNOC in humans and study etiology of NOC of esophageal cancer. When the categories of NOC in urine are less, TNOC index is correlated with NAAs indexes. The results imply that TNOC are implicated in the etiology of esophageal cancer in southern China.