褪黑素与血压昼夜节律的相关性研究

目的通过比较血压昼夜节律异常和正常者的白昼和黑夜的尿中褪黑素的代谢产物6．羟基硫酸褪黑素（6-SMT）的变化，以研究褪黑素与血压昼夜节律的关系。方法对入选者进行24h动态血压监测，测定昼夜血压。用ELISA法测定患者白昼和黑夜尿6-SMT含量，并计算黑夜／白昼尿6-SMT比值。结果各组患者的黑夜尿6-SMT量高于白昼（P〈0．01）。非杓型高血压组的黑夜尿6-SMT量和黑夜／白昼尿6-SMT比值低于杓型高血压组和对照组（P〈0．01）。在各组内，各黑夜／白昼尿6-SMT比值与其组夜间血压下降率均存在正相关（P〈0．05）。结论褪黑素在人体存在昼低夜高的生理节律，血压节律呈现杓型分布的杓型高血压组和对照组，其褪黑素在黑夜分泌较多。而在非杓型高血压组褪黑素黑夜分泌明显减少，与血压昼夜节律异常存在密切关系。褪黑素的黑夜分泌量与夜间血压下降程度相关，其节律性分泌与血压昼夜节律密切相关。

The Relation Effect of Melatonin to the Circadian Rhythm of Blood Pressure

Objective In our study we compared urine 6-SMT(6-sulfatoxymelatonin,product of metabolism of melatonin in urine)in the daytime and nighttime in people whose circadin rhythm of blood pressure was normal or not,to study the relation of circadin rhythm of blood pressure and melatonin.Methods The 24-hour blood pressure was monitored with an automatic ambulatory BP monitor.We determined urine 6-SMT levels in patients by ELISA and calculated ratio of nighttime/daytime urine 6-SMT levels.Statistic analysis was done with SPSS11.5 software.Results Urine 6-SMT levels in the nighttime were all higher than ones in the daytime in non-dipping,dipping and control groups respectively(P<0.01).nighttime urine 6-SMT levels and Ratio of nighttime/daytime urine 6-SMT levels were lower in non-dipping groups than dipping and control groups respectively(P<0.01).There were positive relation in non-dipping groups,dipping and control groups respectively between ratio of nighttime/daytime urine 6-SMT levelsand decreasing ratio of blood pressure in the nighttime(P<0.05).Conclusion The secretion of melatonin has circadian rhythm which is lower in the daytime and higher in the nighttime.The secretion of melatonin is significantly higher in dippers(in dipping group and control group)and the secretion of melatonin is significantly lower in non-dippers.The impairment of the secretion of melatonin in the nighttime is in relation to disorder of circadian rhythm of blood pressure.Circadian rhythm of melatonin is in relation to the development of circadian rhythm of blood pressure,but the mechanism needs more study.