A Comparative Study Of Vascular Endothedolial Function Between Trained And Untrained Subjects At Rest And Exercise State

Objective:The diameter and expansion of the brachial artery in the quiet state and the exercise state of the trained and the untrained were compared,and the effect of long-term exercise exercise on the arterial endothelial function in the quiet state and the exercise state was analyzed.Methods:The undergraduate students from Zhejiang Normal University were selected as the research objects.According to the sports conditions,34 aerobic training-based trainers(all national second-level middle and endurance runners,17 males and 17females)and 40 non-trainers(Non-physical undergraduate students,20 males and 20females),divided into four groups:trained males(TM),trained females(TF),untrained males(UM)and trained female(UF).The subjects completed a 30min 60%VO₂max intensity run on the treadmill.Subjects were tested at rest,30min,60minutes after exercise,and the next morning.Blood pressure(systolic blood pressure,diastolic blood pressure,pulse pressure and mean arterial pressure),heart rate,brachial artery diameter(maximum diameter,resting diameter,delta diameter)and blood flow-mediated dilatation(Flow mediated dilatation,FMD)indicators.The independent sample t-test was used to compare the differences of the indicators between the trainees and the non-trainers in the quiet state and the exercise state.Single-factor repeated measures analysis of variance and post-hoc test were used to analyze and compare the indicators at different time points of the subjects.G*power3.1 was used to calculate the sum sample size and effect size.Results:1)In the quiet state,the diameter of blood vessels in the trained men was larger than that in the untrained men(resting diameter:3.98±0.36mm vs 3.7±0.32mm,P<0.05;maximum diameter:4.33±0.39mm vs 4.02±0.35mm,P<0.05);the diameter of blood vessels in the trained women was larger than that in the untrained women(resting diameter:3.39±0.16mm vs 3.21±0.15mm,P<0.01;maximum Diameter:3.66±0.18mm vs 3.47±0.17mm,P<0.01),but there was no significant difference in brachial artery FMD between trained and untrained(male:8.76±1.66%vs 8.03±1.02%,P=0.108;female:8.09±1.13%vs 8.11±1.27%,P=0.96).From the comparison of trained and untrained people after a workout,there was no difference in the brachial artery diameter between males with the trained and untrained at 30 minutes after exercise,while the resting and maximum brachial artery diameters of trained females were larger than those without training.For both males and females,the resting diameter and maximum diameter of the brachial artery of the trainers were larger than those without training 60min after exercise and the next morning(P<0.05).However,after considering the effect of the difference in diameter before exercise on the diameter after exercise,there was no difference on the resting diameter and the maximum diameter between the trained and untrained at 30min,60min after exercise and the next morning for both males and females(P>0.05).No difference in FMD between trained and untrained people before exercise,30min,60min after exercise,and the next morning.In addition,compared with before exercise,the resting diameter and maximum diameter of the brachial artery increased in trainers and non-trainers 30 minutes after exercise(P<0.01).Males recovered in the morning and females recovered 60 minutes after exercise.FMD decreased significantly after exercise(P<0.05),and then gradually recovered.2)Before exercise,there was no difference in systolic blood pressure(SBP),diastolic blood pressure(DBP),pulse pressure(PP),mean arterial pressure(MAP)between the two groups.There was no difference in blood pressure between the two groups at 30 min and 60min after exercise.In the next morning,SBP and map of TM were lower than that of UM(P<0.05).After exercise,blood pressure decreased,but um recovered faster than TM.UF and TF recovered at 1 hour after exercise.3)Before exercise,the heart rate of the trained was lower than the untrained(P<0.05).30min,60min,and the next morning after exercise,the heart rate of males with training was lower than that of those without training,while the heart rate of female trainers was lower than that of those without training at 60min after exercise,and the heart rates of those with and without training the next morning after exercise All have been restored.After considering the influence of the difference in the basic value,it was found that the heart rate of men with training was still lower than that of those without training at 30min,60min and the next morning after exercise(P<0.01),and there was no difference in the heart rate of women with training and without training..Conclusion:1)Long-term aerobic exercise can increase the resting diameter and maximum diameter of arteries in healthy young people,but FMD has no significant change,suggesting that long-term aerobic exercise can improve the aerobic endothelial function,but FMD should be combined with the changes of resting diameter to evaluate vascular health.2)Acute moderate intensity continuous aerobic therapy for 30 minutes can increase the brachial artery diameter in healthy young people.The effect can last at least 60 minutes in males and 30 minutes in females.