高原移居人群返回低海拔后氧自由基改变对心功能的影响

目的:了解高原暴露人群返回低海拔后氧自由基改变对心功能的影响。方法:923名官兵高原作业110 d后返回低海拔第1天、第15天采样,化学法测定血清超氧化物岐化酶(SOD)和丙二醛(MDA)水平,计算SOD/MDA比值。彩色多普勒超声诊断仪测定Tei指数、左心室射血分数(LVEF)和左心室短轴缩短率(LVFS)。结果:高原短期暴露后返回低海拔初期血中SOD和SOD/MDA比值显著低于对照组,MDA水平显著高于对照组,随时间延长前者呈降低趋势,后者呈增高趋势,第15天时与第1天比较仍有显著差异(P<0.05)。返回低海拔第1天Tei指数显著高于对照组,LVEF、LVFS显著低于对照组(P<0.01);返回第15天Tei指数显著低于第1天水平,LVEF显著高于第1天水平(P<0.01)。结论:高原移居人群返回低海拔后存在着氧化损伤,氧化损伤对心功能有一定影响。

Effect of changed oxygen free radical on cardiac function of plateau migrants after returning to the low altitude

Objective：To investigate the effect of changed oxygen free radical on cardiac function of plateau migrants after returning to the low altitude. Methods： Serum superoxide dismutase （SOD） and malondialdehyde （MDA） of 923 soldiers who have stayed in the area of high altitude for 110 days were determined by chemical method 1 day and 15 days after returning to the low altitude respectively, and SOD/MDA ratio was calculated. Tei index, left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （LVFS） were measured by color Doppler ultrasonography. Results： Serum SOD and SOD/MDA ratio of those who have exposed shortly in the area of high altitude were significantly reduced while MDA were significantly increased in the early stage after returning to the low altitude compared with those of the control group. Serum SOD and SOD/MDA ratio showed a decreasing trend while MDA showed a rising trend later, and there was still significant difference between them at the 1st day and 15th day after returning to the low altitude （P 〈 0.05 ）. Tel index was significantly higher than that of the control group while LVEF and LVFS were significantly lower than that of the control group at the 1 st day after returning to the low altitude （P 〈 0. 01 ）. Tel index was significantly reduced while LVEF was significantly increased at the 15th day compared with that of the 1st day after returning to the low altitude （P 〈0.01）. Conclusion： Oxidative injury exists in plateau migrants after returning to the low altitude which has some effects on cardiac function.