The Effect Of Aerobic Exercise On Cardiovascular And Autonomic Nervous System In Chinese And Caucasian

With the changing of people's lifestyle and diet, the incidence of CVD (Cardiovascular disease) is increasing year by year. Now, CVD mortality accounts for1/3of the global mortality, far more than the number of deaths caused by other diseases, is the most important cause of death. With the increasing of the incidence and mortality of CVD, the consumption of medical resources and expenditure were increased in global. At present CVD has become the most threatening to human health major public health problem in global. The morbidity and mortality of CVD were difference among difference races because the different on Physical fitness, lifestyle and diet. The popular opinion is that the highest incidence rate of CVD is African American's. But the results of comparative study of white American (Caucasian) and the Chinese were not coincident. Now, widely recognized that hypertension, aortic systolic and diastolic dysfunction, cardiac contractility and diastolic dysfunction and autonomic nervous system balance decrease are independent risk factors lead to CVD.Objective:To compare the effect of aerobic exercise on cardiovascular and autonomic nervous system in Chinese and Caucasian by analyzing the data from hemodynamic parameters, arterial systolic and diastolic function, cardiac contractility and diastolic dysfunction, heart rate variability and baroreceptor sensitivity.Methods:62(Chinese,32; Caucasian,30; half is male) subjects aged14-40yrs, who volunteered to participate in this study by recruiting and there were no hypertension, obesity and other cardiovascular and metabolic disease, no history of smoking. The first, V02max, HRmax, R value were gotten using metabolic cart (Quark b2; Cosmed, Italy) and treadmill (Free Motion; Fitness Blowout, USA) under the guidance of Bruce protocol. The second test was begun48hours to1week after the first test. The baseline data were gotten before aerobic exercise in the second test and then took the same measurements at30minutes and60minutes post aerobic exercise. Hemodynamic and arterial systolic and diastolic function were measured using Sphygmocor (Atcor Medical, Australia) and ProSound (Aloka, Japan); cardiac contractility and diastolic function were measured using ProSound (Aloka, Japan); baroreceptor sensitivity was measured using Finometer (FMS, Netherlands) and heart rate variability was measured using Biopac (BioPac systems Inc, US). The exercise is45minutes70%heart rate reserve aerobic exercise. Independent-samples t-test was used to compare the baseline data between Chinese and Caucasian.2×3repeats measures (2races×3 times) AVOVA was used to analyze the difference at30minutes and60minutes post a bout of acute aerobic exercise in Chinese and Caucasian.Results:(1)Hemodynamic parameters:There was different influence on hemodynamic parameters after a bout of45minutes70%heart rate reserve aerobic exercise in Chinese and Caucasian. The decrease of brachial SBP was difference in Chinese (from109±11mmHg to108±10mmHg to106±9mmHg) and Caucasian (from121±9mmHg to117±11mmHg to114±11mmHg)(p<0.05). The brachial DBP (form65±6mmHg to65±5mmHg to64±5mmHg) and MAP (from82±6mmHg to83±6mmHg to81±6mmHg) were decrease in Caucasian. But, the brachial DBP (from60±5mmHg to61±5mmHg to62±5mmHg) and MAP (form75±6mmHg to77±6mmHg to77±5mmHg) were increase in Chinese. The carotid SBP was decrease in Caucasian(from112±12mmHg to114±16mmHg to108±16mmHg)and there was no change in Chinese(from101±14mmHg to104±15mmHg to101±14mmHg)at60minutes post exercise.(2)Vascular: Compare to baseline, there was different (p<0.05) change on carotid Ep between Chinese (from63.3±16.0to70.2±21.6to68.4±18.6) and Caucasian (from61.1±14.5to74.9±21.1to63.8±19.3) at30minutes and60minutes post exercise; The change of carotid P was difference (p<0.05) in Chinese (from5.9±1.3to6.5±1.7to6.5±1.6) and Caucasian (from5.2±1.2to6.4±1.4to5.6±1.3); The change on carotid AC also was difference (p<0.05) between Chinese (from1.2±0.3to l.l±0.4to1.2±0.3) and Caucasian (from1.3±0.4to1.0±0.3to1.3±0.4); there was different (p<0.05) change on femoral AC in Chinese (from1.4±0.5to1.4±0.6to1.3±0.6) and Caucasian (from1.3±0.5to1.2±0.4to1.4±0.6)(3)Cardiac: A bout of aerobic exercise reduced SV by decreasing LVIDd (from47.6±5.9mm to47.6±5.4mm to46.8±5.2mm) and EDV (from108±32ml to107±29ml to104±29ml) and increasing LVIDs (from29.6±4.0mm to30.8±4.5mm to30.0±4.0mm) and EDV (from35±12ml to39±14ml to36±1lml) in Caucasian, the change of SV was caused by decreasing LVIDd (from50.2±5.5mm to48.0±4.7mm to49.3±4.7mm) and EDV (from121±31ml to110±27ml to116±27ml) in Chinese. Compare to baseline, the change of decrease on Em is higher in Caucasian (from19.9±4.5cm/s to17.8±3.6cm/s to18.6±3.9cm/s) than Chinese (from18.0±3.2cm/s to18.1±3.0cm/s to17.8±3.3cm/s)at60minutes post exercise; the change of increase on Am is higher in Chinese(from8.5±2.3cm/s to9.6±2.3cm/s to9.8±2.4cm/s)than Caucasian(from8.2±2.1cm/s to8.0±2.1cm/s to8.6±3.0cm/s); the change of reduce on eV is higher in Chinese(from86.4±13.04cm/s to 77.6±11.84cm/s to76.7±12.14cm/s) than Caucasian (from84.1±16.24cm/s to78.1±12.74cm/s to79.5±13.04cm/s); the change of aV is higher in Chinese (from45.8±11.04cm/s to53.9±9.4cm/s to58.9±9.94cm/s) than Caucasian (from41.7±10.34cm/s to45.8±13.44cm/s to46.3±11.14cm/s).(4) Autonomic nervous system: LF/HF was increased after a bout of acute aerobic exercise, the change of increase was higher in Chinese (from192±194to517±528to296±257) than Caucasian (from192±115to292±226to233±168); The change of nHF was lower in Chinese (from0.43±0.2nu to0.26±0.16nu to0.32±0.16nu) than Caucasian (from0.38±0.14nu to0.32±0.15nu to0.36±0.16nu); The relative increase in nLF is higher in Chinese (from0.55±0.2nu to0.72±0.18nu to0.65±0.17nu) that in Caucasian (from0.6nu±0.15to0.65±0.17nu to0.62±0.17nu);The change of pNN50was difference between Chinese (from23±18.1%to2.3±4.2%tO12.3±17.8%) and Chinese (from31.8±24.6%to15.4±20.7%to21.3±21.7%). The BRS decreased and increased in Chinese (from12.8±6.1ms/mmHg to10.7±15.61ms/mmHg to10.8±5.91ms/mmHg) but increased in Caucasian (M.14.2±91ms/mmHg to14.7±11.61ms/mmHg to15.8±9.91ms/mmHg);The value of BRS (up-up) decreased and then increased in Chinese (from18.7±10.3ms/mmHg to11.3±8.2ms/mmHg to15.7±11.1ms/mmHg) but increased and then decreased in Caucasian (from20.2±14.7ms/mmHg to23±20ms/mmHg to19.5±13.3ms/mmHg)Conclusions:(1)The effect of aerobic exercise on hemodynamic: a bout of acute aerobic exercise can reduce the SBP of the brachial artery of the Chinese and Caucasian, but the change of SBP reduces was high in white Americans compare to Chinese; A bout of acute aerobic exercise can increase brachial DBP and MAP in Chinese, but decreased brachial DBP and MAP in Caucasian; Carotid SBP can been decreased in Caucasian caused by acute exercise and there was no change in Chinese. These results suggest that it is better in lowing blood pressure and cardiac load following a bout of acute aerobic exercise in Caucasian than Chinese.(2)The effect of aerobic exercises on artery: the value of carotid AC, Ep,β can been increased in Caucasian after a bout of acute aerobic exercise, but decreased in carotid AC and increased in carotid Ep and p in Chinese and the impact was greater in Caucasian than Chinese. The exercise can reduced femoral AC in Chinese and increased in Caucasian. These results suggest that the improvement of arterial function may be due to improve arterial compliance and elasticity in Caucasian following a bout of acute aerobic exercise. But the arterial compliance and elasticity were reduced in Chinese after a bout of acute aerobic exercise.(3) The effect of aerobic exercises on cardiac:a bout of aerobic exercise reduced SV by decreasing LVIDd and EDV, increasing LVIDs and EDV in Caucasian, the reduction of SV was caused by decreasing LVIDd and EDV in Chinese. Mainly, the left ventricular contraction is not complete in Chinese, and diastolic incomplete in Caucasian; the absolute increase in CO was higher in Chinese than Caucasian which caused by increase of heart rate after exercise; Exercise could cause a decrease in left ventricular diastolic function, but the Chinese to.recover earlier than Caucasian; could reduce left ventricular active relaxation ability, and the reduction was greater in Caucasian than Chinese; Could reduce the blood flow form left atrium to left ventricular during early diastolic, the reduction was lower in Chinese than Caucasian; could improve left ventricular compliance, the degree of improvement of left ventricular compliance of the Chinese more than Caucasian; Could reduce the left ventricular rapid filling, The change of decrease is greater in Chinese than Caucasian; could cause increasing of left atrium contraction in a compensatory which is greater in Chinese than Caucasian. These results suggest that cardiac diastolic function was reduced following a bout of acute aerobic exercise, the changes in cardiac stress was greater in Chinese than Caucasian.(4) The effect of aerobic exercises on ANS:aerobic exercise could enhance the regulatory function of the ANS which is greater in Chinese than Caucasian. The enhancement of the regulatory function of the autonomic nervous system was caused by enhancing sympathetic nervous system excitability and reducing parasympathetic nervous system excitability. The change of enhancement of sympathetic nervous system and reduction of parasympathetic nervous system excitability were greater in Chinese than Caucasian. These results suggest that ANS function was increased following a bout of acute aerobic exercise, the changes ANS stress was greater in Chinese than Caucasian.