Study On The Vascular Endothelial Diastolic Function In Tibetan Patients With Hypertension At High Altitude And Its Correlation With Oxidative Stress

Objective:This paper is aimed at comparing the differences between subjects in different altitudes(3800 meters in high altitude places of Yushu Prefecture,2300 meters in places of Xining)and with or without hypertension in terms of the levels of FMD,serum GSSG(oxidized glutathione),SOD(superoxide dismutase)and NO,as well as figuring out the correlation between these four indicators.Methods:The clinical data of 35 Tibetan subjects with hypertension and 32 control cases in high altitude places of Yushu Prefecture were collected,as well as the data of 32 Tibetan subjects with hypertension and 35 control cases in places of Xining.Their serum GSSG,SOD,and NO levels were measured by ELISA,and the brachial artery endothelial flow-mediated function(FMD)was measured by Endothelial function tester.Appropriate statistical methods were used to analyze the data.Results:Comparison with same altitudes:The levels of GSSG,SOD,NO and FMD in Tibetan healthy controls in high altitude places of Yushu or in places of Xining were all significantly higher than those with hypertension in the same region.(P<0.05).Comparison with different altitudes:The levels of GSSG,SOD,NO,and FMD in healthy controls in Xining were all significantly higher than those healthy controls in high altitude places of Yushu(P<0.05);and the levels of GSSG,SOD,NO,and FMD in subjects with hypertension in Xining were all significantly higher than those with hypertension in high altitude places of Yushu(P<0.05).There was a positive correlation between the FMD and GSSG,SOD,and NO levels in subjects with hypertension at the same altitude.Conclusion:1.The anti-oxidation capacity of healthy Tibetans and hypertensive Tibetans at the region with a high altitude is lower than that of healthy Tibetans and hypertensive Tibetans in the Xining region.2.As the altitude rises,the anti-oxidation capacity of healthy Tibetans and hypertensive Tibetans both decline.3.With the decrease in anti-oxidation capacity,oxidative stress increases,resulting in unbalanced anti-oxidation/oxidation capacity and decreased vascular endothelial diastolic function.