Study On The Changes,accumulation And Influencing Factors Of Cardiac Biomarkers Induced By Acute Endurance Exercise

Objective:Endurance athletes often arrange in a week,repeated to complete a long time of high intensity training or competition.The changes of myocardial biomarkers after repeated endurance exercise and their related influencing factors and clinical significance remain unclear.This study aims to observe the changes of myocardial biomarkers before and after two acute endurance exercises.To explore the possible effects of Blood Volume（BV）,renal function markers and inflammatory factors on the changes of myocardial biomarkers,and to provide the basis for determining its clinical significance.Methods:Ten marathon runners(age:27.5±4.7 year,height:171.0±5.7 cm,weight:62.1±7.3 kg,VO_2max:59.8±8.0 ml/kg/min,training years:9.4±5.3 year)completed two long endurance exercises（exe1,exe2）.There was no significant difference between the two groups in the intensity of exercise（95%individual ventilation threshold,13.2±1.6 km/h）,time（90 min）,distance（19.8±2.4 km）,average Heart Rate（HR）during exercise（exe1,exe2:156.4±16.2,156.4±7.7 beat/min,P=0.99）,and the interval between two acute exercises was one week.BV was measured and venous blood was collected before,4 and 28 h after exercise,respectively,to determine biomarkers of myocardial injury:High Sensitive CardiacTroponin I（hs-cTnI）,High Sensitive CardiacTroponin T（hs-cTnT）,and biomarkers of myocardial fibrosis:Galactin-3,Suppression of Tumorigenicity 2（s ST-2）,and biomarkers of renal function:Kidney injury molecule 1（KIM-1）,Neutropil Gelatinase Aassociated Lipocalin（NGAL）,Cystatin C（Cys C）,and biomarkers of inflammation:High Sensitive C-reactive Protein（hs-CRP）and interleukin-6（IL-6）levels were detected.Results:Biomarkers of myocardial injury:（hs-cTnI,hs-cTnT）hs-cTnI:Serum hs-cTnI level was significantly increased at 4 h after acute endurance exercise exe1,and returned to quiet level at 28 h（Pre:2.87±3.32 ng/L;Post-4 h:10.60±10.08ng/L;Post-28 h:4.71±8.23 ng/L,P<0.01）;The release rate was the same after exe2（Pre:3.77±3.23 ng/L;Post-4 h:6.13±4.97 ng/L;Post-28 h:2.93±3.14 ng/L,P<0.01）;There was no difference between groups at corresponding time points between exe1 and exe2.hs-cTnT:Serum hs-cTnT level increased significantly 4 h after acute endurance exercise exe1,and returned to quiet level 28 h after acute endurance exercise（Pre:6.39±4.87 ng/L;Post-4 h:17.59±12.90 ng/L;Post-28 h:6.05±2.91 ng/L,P<0.05）;It was significantly increased at 4h after exe2（Pre:8.89±9.26 ng/L;Post-4 h:14.46±11.56 ng/L;Post-28 h:5.23±1.87ng/L,P<0.01）;There was no difference between groups at corresponding time points between exe1 and exe 2.Biomarkers of myocardial fibrosis:（Galactin-3,s ST-2）Galectin-3:Serum Galectin-3 level increased significantly 4 h after acute endurance exercise exe1,and returned to quiet level at 28 h（Pre:8.23±2.26 ng/m L;Post-4 h:9.99±2.45ng/m L;Post-28 h:8.05±2.25 ng/m L,P<0.05）;There was no significant increase after exe2.There was no difference between groups at corresponding time points between exe1 and exe2.s ST-2:Serum s ST-2 level was significantly increased at 4 h after acute endurance exercise exe1,but did not return to quiet level at 28 h（Pre:20.30±7.64 ng/m L;Post-4 h:26.55±7.66ng/m L;Post-28 h:23.45±9.08 ng/m L,P<0.01）;It was significantly increased at 4 h after exe2,and returned to quiet level at 28 h（Pre:22.76±9.25 ng/m L;Post-4 h:28.42±9.75ng/m L;Post-28 h:23.96±7.17 ng/m L,P<0.05）;There was no difference between groups at corresponding time points between exe1 and exe2.BV:There was no significant difference in BV before and after two acute endurance exercises.Kidney function biomarkers:（NGAL,KIM-1,Cys C,GFR）NGAL:Serum NGAL level was significantly decreased 28 h after acute endurance exercise exe1（Pre:89.58±38.04 ng/m L;Post-28 h:71.07±27.54 ng/m L,P<0.05）;There was no difference between groups at corresponding time points between exe1 and exe2.There was no significant difference in KIM-1,Cys C and GFR before and after two acute endurance exercises.Inflammation biomarkers:（hs-CRP,IL-6）hs-CRP:Serum hs-CRP level was significantly increased 28 h after acute endurance exercise exe1（Pre:0.64±0.24 mg/L;Post-28 h:0.99±0.52 mg/L,P<0.01）;There was no difference between groups at corresponding time points between exe1 and exe2.IL-6:Serum IL-6 level was significantly decreased 4 h after acute endurance exe2 and continued to decrease 28 h after exercise,which was significantly lower than that before exercise（Pre:14.79±10.58 ng/L;Post-4 h:1.49±1.97 ng/L;Post-28 h:0.88±0.93ng/L,P<0.01）.Exe2 quiet value of serum IL-6 level was significantly higher than exe1 quiet value（exe1 pre:1.77±1.26 ng/L;exe2 pre:14.79±10.58 ng/L,P<0.01）;4 h after exe2was significantly higher than that after exe1（exe1 post-4 h:0.51±0.29 ng/L;exe2 post-4 h:1.49±1.97 ng/L,P<0.05）.Conclusion:1)After repeated endurance exercise for a week,biomarkers of myocardial injury increased at 4 h after exercise and returned to the pre-exercise level at 28 h;The change rule was the same after the two movements.2)There were individual differences in the release of biomarkers of myocardial fibrosis after repeated endurance exercise with a one-week interval,and the level of s ST-2 during the second exercise tended to be higher than that during the first exercise.3)No association was found between BV,renal function,or inflammation with cardiac biomarkers...