海拔3417m世居及移居者无氧代谢阈与左心功能关系的探讨

Relationship between Anaerobic Threshold and Cardiac Function in Native Tibetans and Han Migrators at 3417m Altitude.

在海拔３４１７ｍ对１８名健康世居藏族和１６名移居汉族用Ｊｅａｇｅｒ气体代谢自动分析系统和心阻抗图测定了无氧阈（ＡＴ）和最大摄氧量（Ｖ·Ｏ２ｍａｘ）时的ＳＶ、ＣＯ、ＰＥＰ／ＬＶＥＴ和ＳａＯ２。结果显示：在海拔３４１７ｍ测得ＡＴ值明显低于海平面；世居藏族ＡＴ出现较晚，并且ＡＴ时的功率、Ｖ·Ｏ２、ＭＶ、ＨＲ、ＣＯ、ＳＶ均高于移居汉族，而ＰＥＰ／ＬＶＥＴ比值小于移居组（Ｐ＜０．０１）；两组的ＳＶ峰值出现时间不同，世居组在ＡＴ或ＡＴ以后出现的占７２％，而移居组仅占３１％（Ｐ＜０．０５）；在最大负荷运动时，世居组的ＳａＯ２为８２．７４％，较运动前下降了８．９％，而移居组的ＳａＯ２为７６．５％，较运动前下降了１３．７％。研究结果提示，心泵功能是影响ＡＴ的重要因素之一。世居组ＡＴ出现的较晚，与其心肺储备功能强和组织细胞利用氧的能力较高有关，这是世居藏族对高原低氧环境长期适应的结果。

Cardiac and pulmonary functions were examined at an altitude of 3417m in 18 healthy male native Tibetans and 16 Han immigration male residents(matched for age,height and weight).The results showed that:(1)There was a significant decrease in anaerobic threshold (AT) at the altitude of 3417m as compared with that at sea level;(2)At AT the Tibetants had greater O 2 uptake,exercise workload,minute Volume(MV),heart rate(HR),cardiac output(CO) and stroke volume(SV) as compared with the Hans,but P/L(pre-ejection-period/lift ventricular ejection time) was shorter than the Hans;(3)Peak of SV appeared at AT or behind AT was 72% in the Tibetans but only 31% in the Hans(P<0.05);(4)At maximal workload SaO 2 was 82.47% in the Tibetans and 76.5% in the Hans (P<0.01).These results suggested that cardiac function was one of the important factors affecting AT.The increase of cardiac-pulmonary reserve function in the Tibetans might reflect the genetic adaptation of the Tibetans to hypoxic environment.