Association Between Intrarenal Arterial Resistance And Diastolic Dysfunction In Type2Diabetes

Objective:In comparison to the well established changes in compliance that occur atthe large vessel level in diabetes, much less is known about the changes in thestiffnessof the cardiovascular system at the end-organ level.We examined the associationbetween resistance of the intrarenal arteries of the kidney and left ventricular diastolicdysfunction (LVDD).Method:We studied80unselected clinic patients,which were diagnosed type2diabetes during July2012and October2013.The control group had40normalcases.The ultrasonic instrument was Philips IU22.All the patients lay on the side orlay on the back.Under the color Doppler ultrasound,the two sides kidney blood flowwere observed.We choose the blood flow of interlobar renal arteries,including peaksystolic velocity(Vs),peak diastolic velocity (Vd),and the resistance index（RI）.Theseparameters can estimate intrarenal vascular resistance.The resistance index(RI)=(peaksystolic velocity-minimum diastolic velocity)/peak systolic velocity.At least threesamples were taken and the mean was calculated as value.A transthoracicechocardiogram(TTE):Two-dimensional echo and Doppler recordings were obtainedthe interventricular septum thickness (IVS),LV posterior wall thickness(LVPW),leftatrial diameter(LAD)were measured,Transmitral recordings were used for measurements of peak E velocity in cm/s(peak early transmitral filling velocityduringearly diastole),peak A velocity in cm/s(peak transmitral atrial.filling velocityduring late diastole),IRT in ms(Isovolumic Relaxation Time).Tissue Doppler imagingevaluation of the medial mitral annular velocity was performed during passive filling(E’cm/s) in each patient.Then calculate the results of E/A ratio,E/E’ratio.The routinebiochemistry results were checked when the patients entered the hospital.Two couplesof parameters were analyzed.Result:1.Intrarenal arterial resistance:Renal RI values of diabetes was significantlyhigher in subjects with(0.66±0.05)when compared with those who had a normal(0.54±0.08,P<0.05),Vd(9.79±5.17)values of diabetes was reduced when compared withthose normal ubjects(14.99±8.19,P<0.05).2.Ultrasonic cardiogram values:E’、E/E’ratio,LVPW values of normal and diabetes had statistical discrepancy(E’:11.4±1.5,9.7±1.6,P<0.05;E/E’:9.6±2.3,10.3±3.0,P<0.05;LVPW:8±1,10±1,P<0.05).Asvalues of systolic functionEF%、FS%values of normal and diabetes had no statisticaldiscrepancy.3.Correlation analysis between renal arterial(RI)and cardiac parameter:RI correlated with markers of diastolic dysfunction including the E/E’ ratio(r=0.31，P<0.001)、 the E/A ratio(r=-0.36,P<0.05)and LAD(r=0.36,P<0.05).The strongestcorrelation is between E/E’ ratio and the resistance index.4.Correlation analysisbetween E/E’ ratio and biochemical criterion:E/E’ ratio was correlated with age，diabetic duration,systolic blood pressure,Creatinine,UAER and eGFR.In multipleregression analysis,diabetic duration(b=0.322,P<0.001) and UAER(b=0.431,P<0.001)an independent risk factor for with E/E’ ratio.Conclusion:Early type2diabetes not only have an increased renal arterialresistance,but also appear diastolic dysfunction.Further more,with the increasingintrarenal vascular resistance,diastolic function gradually reduced.