The Changes Of The Cardiovascular System Under Military Stress And The Protection Of Military Stress Injury

Background and Objective:Stress as an important cause of incentive death of a variety of major human diseases have already been identified. The mechanism of the injury on the body and the prevention measures has attracted wide attention. The soldiers as a special group, they face more complex stress factors and withstand more severe stress.Military stress is one of the reactions of soldiers when they faced stress in the war. It has become one of the main non-combat attrition. China's military stress research has clearly failed to that of some foreign armies. The reports about the mechanism that military stress can hurt cardiovascular function were rare. This research focuses on the mechanisms how the military stress lead to cardiovascular system injury by using some data collected from the scene of military operations. Then we do some tests in the laboratory to study the mechanism of military stress which lead to cardiovascular system injury and to research the protection measures.The first part Military stress on cardiovascular function of relevant soldiersMethods:two hundred soldiers participating in war-game were involved in test group, ninety-seven soldiers from logistics department in war-game were involved in control group, aged 18～49 years,165±4.5cm in height, weighted 60±5.0kg. Military Stress levels and myocardium serum markers were measured; Psychological stress were analyzed by the symptom checklist-90 (SCL-90), Fatigue Assessment Instrument Questionnaire(FAI) and Pittsburgh sleep quality index (PSQI); 24-hour Holter monitoring electrocardiogram were recorded to observe cardiac function.Results:For the test group, the serum concentrations of H-FABP, CRP,β-EP (P<0.01,P<0.01,P<0.01) and levels of psychological stress after war-game were significantly higher than those in control group; High strength military training resulted in significant elevation of the rate of cardiac arrhythmia.Conclusions:The findings in present study indicate that high military stress may induce great physical and psychological stress and force the soldiers to be accumulated fatigue; High strength military stress resulted in cardiac arrhythmia and myocardial injury (the major types of cardiac arrhythmia are sinus arrhythmia, atrioventricular block, atrial premature beats, premature ventricular beats, abnormal ST segment and T wave).The second part Effect of peroxisome proliferator-activated receptorγon the myocardial injury caused by stress in miceMethods:Fifty mice were randomly assigned to control group, exhausted-swimming group, white noise group, exhausted-swimming plus white noise group, pioglitazone intervention group,10 mice in each group. The changes in myocardium structure were observed using HE staining. The serum levels of troponinⅠ(TnⅠ), corticosterone (CORT), superoxide dismutase (SOD) were determined by ELISA. The expression of PPARγmRNA and protein was detected by real-time fluorescence quantitative PCR and Western blot respectively.Results HE staining showed normal myocardial structure in all groups. The serum levels of CORT(μg/L) and TnⅠ(μg/L)were raised after different stress attack (CORT:106.75±33.96,96.43±20.63,173.17±22.28; TnⅠ:0.113±0.032, 0.077±0.034,0.133±0.041; P<0.01), while the level of SOD (u/ml) was reduced (103.36±10.43,124.93±8.47,97.16±17.30; P<0.01).The expressions of PPARγ mRNA and protein were depressed in exhausted-swimming group, white noise group, and exhausted-swimming plus white noise group. In the pioglitazone group, the serum levels of TnI, CORT, and SOD and the expressions of PPARy mRNA and protein were resumed.Conclusions Stress may result in the myocardial injury in mice. The expression of PPARy in myocardial tissue was reduced under stress. Pioglitazone intervention can prevent myocardium against the injury caused by stress.