高海拔低氧并重体力劳动对军人心功能的影响及返回低海拔后的恢复变化

Effects of high altitude hypoxia combined with heavy physical workload on cardiac function of militarypersonnel and recover effects when returning to normal altitude

目的观察高海拔低氧并重体力劳动对军人心功能影响及返回低海拔后恢复变化情况。方法根据快速进入高海拔（3700m）地区并从事重体力劳动的96例男性军人的症状，将其分为重度急性高原反应（acute high altitude reaction, AHAR）组、中度AHAR组、轻度AHAR组和无AHAR组；在50d后其下撤前及返回低海拔（1500m）后12h、15d测定血清肌酸激酶同功酶-MB（creatine kinase isoenzyme-MB, CK-MB）、乳酸脱氢酶同功酶-1（lactic dehydrogenase isoenzyme-1，LDH-1）、心肌运动指数（又称Tei指数）、左心室射血分数（left ventricular ejection fraction, LVEF）和左心室短轴缩短率（left ventricular fractional shortening, LVFS），并与低海拔（1500m）地区的50名健康军人（对照组）比较。结果96例中发生AHAR者71例（74．0％），其中轻度25例（占35．2％）、中度22例（占31．0％）、重度24例（占33．8％）。重度AHAR组血清CK-MB、LDH-1水平、Tei指数显著高于轻中度AHAR组和无AHAR组（P〈o．01），LVEF、LVFS显著低于轻中度AHAR组和无AHAR组（P〈o．01），轻中度AHAR组与无AHAR组之间各项指标差异亦有统计学意义（P〈0．01）。海拔3700m50d，血清CK-MB、LDH-1与Tei指数呈显著正相关（r=0．625、0．598，P〈0．01），与LVEF、LVFS显著负相关（r=-0．716、-0．658、-0．639、-0．727，P〈0．01）。海拔3700m50d，官兵血清CK—MB、LDH-1水平、Tei指数显著高于自身海拔1500m12h、1500m15d时及对照组，LVEF、LVFS显著低于自身海拔1500m12h、1500m15d时及对照组（t=7．146-28．613，P〈O．01）；海拔1500m12h与自身1500m15d及对照组之间比较，各项指标差异亦有统计学意义（t=8．677-17．852，P〈0．01），但海拔1500rn15d与对照组之间比较，各项指标差异均无统计学意义（t=0．612-1．558，P〉0．05）。结论高海拔低氧并重体力劳动对部队官兵的心功能有明显损害，随着AHAR程度的加重而加重；返回低海拔后12h有显著改善，15d恢复到正常水平。

Objective To assess the effects of hypoxia combined with heavy physical workload on cardiac function of the military personnel who stationed at high altitude and to conclude the recovery effects as the personnel returning to normal altitude. Methods Ninety-six male military personnel, who rushed to plateau （3700 m） and undertaken heavy physical work for 50 days, were divided into severe, moderate, mild and no acute high altitude reaction （AHAR） group by their AHAR symptoms. Serum creatine kinase isoenzyme-MB （CK-MB） and lactic dehydrogenase isoenzyme-1 （LDH-1）, myocardial performance index （Tei index）, left ventricular ejection fraction （LVEF）, andleft ventricular fractional shortening （LVFS） were respectively measured before they returned to, 12 h and 15 d after they stationed at normal altitude （1500 m）. Another 50 healthy volunteers who stationed at 1500 m were chosen as control group. Results The incidence of AHAR was 74.0% （71/96）, including 32. 5% （2-5/71） mild, 31. 0% （22/71） moderate and 33. 8%（24/71） severe cases. Level of serum CK-MB, LDH-1 and Tei index of severe group were significantly higher than those of moderate, mild and no AHAR group （P〈0. 01）, while LVEF, LVFS were significantlylower （P〈0. 01）. For stationed at 3700 m for 50 d, personnel＇s CK-MB and LDH-1 level was positively correlated with Tei index （r= 0. 625, 0. 598, P〈0. 01）, and negatively correlated with LVEFandLVFS（r=0.716, -0.658, -0.639, -0.727, P〈0.01）. The CK-MBand LDH-1 level and Tei index that gathered for 50-d stay were significantly higher than those of theirs stationed at 1500 m for 12 h and 15 d respectively, as well as higher than those of control group, but LVEF and LVFS were significantly lower in same comparison （t = 7. 146-28. 613, P〈0. 01）.The selfcomparisons between 12 h and 15 d stationings respectively in AHAR and control group showed significant differences 0=8. 677-17. 852, P〈0.01）. For staying 15 d at 1500 m, parameters showed no significant difference with control groupts （t= 0. 612-1. 558, P〉0.05）. Conclusions Hypoxia with heavy physical workload could obviously cause military personnells cardiac function impairment and the harm is aggravated with the severity of AHAR. The cardiac function would obviously improve as returning to normal altitude for 12 h, and 15-d recovery would enable cardiac function normalized.