Plasma Endothelin-1 (ET-1) is a useful marker for early renal dysfunction in a general population

内皮素-1(ET-1)是一种来源于内皮的强效血管收缩因子。几项在人类身上进行的少量研究表明，高血压患者的血浆ET-1水平较高，但在其他研究中并非如此。此外，在少数受试者中已显示尿毒症患者ET-1升高。然而，目前还没有关于ET-1水平是否与肾功能障碍有关的流行病学调查。1999年，共有1,492名受试者接受了健康检查。获得了1,450例空腹ET-1的数据。采用放射免疫法测定血浆ET-1水平。我们还测量了体重指数、收缩压和舒张压、血红蛋白、胆固醇、尿素氮、肌酐和尿酸。肌酐清除量按Cockcroft-Gault肾功能评估公式计算：[(140岁)×体重(Kg)]/[72×血肌酐](女性×0.85)。采用问卷调查法进行吸烟习惯评价。ET-1男性为4.93±1.73pg/ml，女性为4.84±1.54pg/ml。肾小球滤过率(GFR)男性为69.9±20.7ml/min，女性为65.3±18.6ml/min。ET-1与肾小球滤过率呈强负相关(P&lt；0.001)。在控制了与ET-1关系最密切的年龄后，这种关联仍然显著。为了进一步研究血浆ET-1水平与GFR之间的关系，我们进行了协方差分析。平均ET-1按GFR的五分位数分层，根据年龄、性别和吸烟进行调整，这与ET-1显著相关。ET-1与GFR呈直线负相关趋势(p=0.03)。我们的数据表明，在流行病学研究中，升高的ET-1是肾功能障碍的有用标记物。

Endothelin-1 (ET-1) is a potent vasoconstrictor derived from the endothelium. Several studies with a small number in humans showed high plasma ET-1 levels in hypertension but did not so in other studies. Furthermore, it has been shown in a small number of subjects that ET-1 is elevated in uremic patients. However, there have been no epidemiological surveys as to whether ET-1 level is related to renal dysfunction. A total of 1,492 subjects received a health examination in 1999. The data for fasting ET-1 of 1,450 were obtained. A specific radioimmunoassay was used to measure ET-1 levels. We also measured BMI, systolic and diastolic blood pressure (BP), hemoglobin A_<1c>, cholesterol, BUN, creatinine, and uric acid. Creatinine clearance was calculated by the Cockcroft-Gault formula for assessing kidney function : [(140-age)×weight(kg)]/[72×serum creatinine](×0.85 for women). Smoking habit was evaluated by questionnaire. Mean ET-1 was 4.93±1.73pg/ml in men and 4.84±1.54pg/ml in women. Mean glomerular filtration rate (GFR) was 69.9±20.7ml/min in men and 65.3±18.6ml/min in women. ET-1 showed a strong inverse association (p<0.001) with GFR. After controlling for age, which is the strongest relation to ET-1, the association remained significant. In order to further examine the association between plasma ET-1 levels and GFR, we performed analysis of covariance. The mean ET-1 stratified by quintiles of GFR adjusted for age, sex and smoking, which is significantly associated with ET-1. There was a linear and significant inversely trend (p=0.03) between ET-1 and GFR. Our data suggest that elevated ET-1 is a useful marker for renal dysfunction in an epidemiological study.