Blood Flow Restriction Training On Cardiac Function In Patients With Essential Hypertension By Improving Vascular Endothelial Function

Objective:This study aims to explore the effects of blood flow restriction combined with low intensity resistance exercise on vascular endothelial function,cardiac autonomic nervous function and cardiac function in patients with essential hypertension,and to lay a theoretical foundation for more scientific and reasonable resistance exercise in patients with hypertension in the future.Methods:45 Patients aged 50-77 years with essential hypertension were randomly divided into three groups:high intensity resistance exercise group(HE),restricted blood flow combined with low intensity resistance exercise group(LE-BFR),and low intensity resistance exercise group(LE).Subjects were required to complete the anti-resistance knee extension exercises on both sides of lower limbs for 20 times within 60s,and a total of 5 groups were required to complete the exercises.The groups rested for 60s and exercised for 3days/week for 12 weeks.Among them,the HE received 65%1RM high-intensity resistance knee extension exercise,the LE-BFR group received 130%SBP blood flow restriction with 30%1RM low-intensity resistance knee extension exercise,and the LE group received 30%1RM low-intensity resistance knee extension exercise.1RM was measured before,4weeks,8weeks,and after exercise using the Biodex isokinetic strength assessment training system.Subjects’blood pressure was measured using a Japanese OMRON electronic sphygmomanometer.VEGF,ET-1,NOS and NO were detected by ELISA.Cardiac function indexes such as ejection fraction were detected by color Doppler ultrasonography with Philips Xin Yue IE33.peripheral vascular function indexes,such as total peripheral resistance,were measured by German Total Arteriosclerosis Detector(VICORDER).Use First beat heart rate monitor equipment records the subjects from within 30 min after 15 min before the movement of R-R interphase and heart rate variability(HRV)analysis,including time domain index(heart rate(HR)and RMS of phase difference between adjacent R-R(RMSSD))and frequency domain index(low frequency band power(LF ms~2),high frequency power(HF ms~2)and LF/HF ratio).The above tests were carried out twice,one before and one after the experiment.Results:(1)After 12 weeks of exercise intervention,1RM in HE,LE-BFR and LE group increased significantly(P<0.05),and compared with LE group,1RM in HE and LE-BFR groups increased more significantly(P<0.05).(2)ET-1 was significantly decreased in HE group(P<0.01),VEGF,NOS and NO were significantly increased in LE-BFR group(P<0.05),and ET-1 was significantly decreased(P<0.01).Compared with HE and LE groups,VEGF was significantly increased in LE-BFR group(P<0.05),and ET-1 was significantly decreased in LE group(P<0.05).(3)HE set of TG,ALD and AT-Ⅱpresent a decreased significantly(P<0.05),LE-BFR group TC,TG,ALD and the AT-Ⅱshowed significantly decreased(P<0.05),TG,ALD and the AT-ⅡLE group were decreased,but cut cannot constitute a statistical significance(P<0.05).(4)SV and CO were significantly increased in HE and LE BFR groups(P<0.01),and TPR were significantly decreased(P<0.05).Compared with LE group,TPR was significantly decreased in HE and LE BFR groups(P<0.05),while SV and CO were significantly increased(P<0.05).PP in HE group and MAP in LE-BFR group were significantly decreased(P<0.05).(5)After 12 weeks of exercise,HF in HE group was significantly decreased(P<0.05),while LF/HF in HE group was significantly increased(P<0.05).In LE-BFR group,HF was significantly increased(P<0.05),and LF/HF was significantly decreased(P<0.05).Under exercise state,HR in HE,LE-BFR and LE group were significantly higher than before exercise(P<0.05),and HR in HE and LE-BFR group was significantly higher than that in LE group(P<0.05).RMSSD,HF and LF in HE and LE-BFR groups were significantly lower than before exercise(P<0.05),and LF in LE group was significantly lower than before exercise(P<0.05).LF/HF in LE-BFR group was significantly higher than that before exercise(P<0.05).In the state of recovery after exercise,HR in HE group was significantly higher than that before exercise(P<0.05),RMSSD was significantly lower than that before exercise(P<0.05),while the recovery was observed in LE BFR and LE groups(P>0.05).The levels of HF and LF in HE group were significantly lower than those before exercise(P<0.05),and the levels of HF,LF and LF/HF in LE-BFR group were recovered(P>0.05).(6)The SBP in HE group was significantly decreased(P<0.05),and the SBP in LE-BFR group was significantly decreased(P<0.01).Compared with HE and LE groups,the SBP in LE-BFR group was significantly lower than that in HE and LE groups(P<0.05).He,LE-BFR,LVEF and FS in LE group were significantly increased(P<0.05).Conclusion:1.High intensity resistance exercise(HE)can reduce the expression of ET-1,reduce the activity of RAAS,improve the endothelial function to some extent,thereby reducing the total Peripheral vascular resistance,and achieve the effect of reducing blood pressure and improving cardiac function in patients with hypertension.2.Limited blood flow resistance combined with low intensity exercise(LE-BFR)can significantly improve cardiac vascular endothelial function,increase the expression of VEGF,NOS and NO in the blood,the lower expression of ET-1 in the blood,cholesterol and triglyceride levels in the blood also dropped significantly,RAAS activity decline,total Peripheral resistance to drop,the blood pressure of hypertension patients decreased significantly,improve heart pump function.3.Low intensity resistance exercise(LE)only down-regulated the expression of ET-1 and increased the cardiac LVEF and FS,but did not significantly reduce the blood pressure of patients with hypertension,and the improvement of cardiac function was limited.4.Both HE and LE-BFR can effectively reduce blood pressure and improve cardiac function in patients with essential hypertension.However,HE makes patients’sympathetic nerves overexcited,while LE-BFR makes patients’cardiac autonomic nerve regulation tend to be parasympathetic and inhibit the sympathetic nerves overexcited.Therefore,the hypotensive effect is better than HE,and the risk of cardiovascular accidents is smaller and the safety is higher.5.In conclusion,LE-BFR is recommended for future resistance exercise in patients with essential hypertension.