神经肽Y在倾斜试验诱发血管迷走性晕厥中的作用及其意义

为研究神经肽Ｙ（ＮＰＹ）在倾斜试验诱发血管迷走性晕厥机制中的作用，采用放射免疫分析法测定１３例倾斜试验阳性（阳性组）、１１例倾斜试验阴性（阴性组）的不明原因晕厥患者和８例倾斜试验阴性的健康对照者倾斜试验时肘静脉血浆ＮＰＹ浓度。结果：倾斜前阳性组ＮＰＹ浓度（经自然对数转换）明显低于对照组（４．６７±０．５３ｌｎ－ｐｇ／ｍｌｖｓ５．１７±０．３８ｌｎ－ｐｇ／ｍｌ，Ｐ＜０．０５）。倾斜时对照组和阴性组ＮＰＹ浓度较倾斜前无明显变化，阳性组倾斜５ｍｉｎ时ＮＰＹ浓度较倾斜前显著降低（４．０１±０．９１ｌｎ－ｐｇ／ｍｌｖｓ４．６７±０．５３ｌｎ－ｐｇ／ｍｌ，Ｐ＜０．０１），随后则呈上升趋势并达到倾斜前水平。倾斜５ｍｉｎＮＰＹ浓度较倾斜前下降达３０ｐｇ／ｍｌ以上对倾斜试验结果的阳性预测值为７７％、敏感性为８３％、特异性为８２％。结论：ＮＰＹ在倾斜试验诱发血管迷走性晕厥中起重要作用。检测不明原因晕厥患者倾斜试验早期ＮＰＹ血浓度变化可较好预测倾斜试验结果。

Role of Neuropeptide Y in Genesis of Vasovagal Syncope Induced by Tilt and Its Clinical Diagnostic Value

To study the role of neuropeptide Y(NPY) in the genesis of vasovagal syncope (VS) induced by tilt test and its clinical diagnostic value,the plasma NPY concentrations were determined by radioimmunoassy in 13 unexplained syncope patients with positive tilt response (positive group),11 unexplained syncope patients with negative tilt response (negative group) and 8 healthy control subjects with negative tilt response before and during tilting.Results: Comparied with healthy control subjects,NPY levels were lower in positive group (4.67±0.53 ln pg/ml vs 5.17±0.38 ln pg/ml, P <0.05).Tilting caused an early (5 minutes) decrease in NPY levels in positive group (4.01±0.91 ln pg/ml vs 4.67±0.53 ln pg/ml, P <0.05) and followed by a trend to increase during late tilting,but no significant change in negative group and control subjects.A early decrease of NPY concentrations more than 30 pg/ml predicted 77% positive tilt response with 83% sensitivity and 82% specificity.Conclusions: NPY and autonomic nervous system play an important role in the genisis of vasovagal syncope induced by tilting.Analysis of the change of plasma NPY levels during early tilting can predict the results of tilting test.