Preliminary Study On The Intradialytic Blood Pressure Changes And Influencing Factors In Maintenance Hemodialysis Patients

ObjectiveTo understand the blood pressure variability(BPV) and the influencing factors through ambulatory blood pressure monitoring during dialysis in maintenance hemodialysis(MHD) patients. To analyse the water load and its correlation with BPV by bioelectrical impedance in MHD patients. To observe the level of plasma asymmetric dimethylarginine (ADMA) and study the correlation between ADMA and the different blood pressure change in MHD patients.MethordWe enrolled81MHD patients into the study. Using dynamic blood pressure monitor to monitoring the blood pressure around the dialysis. BPV was estimated with the coefficient of variation(CV) and standard deviation(SD). Patients are divided into two groups according to the average of SBP-CV:high SBPV group and low SBPV group. The possible effect factors such as age, dialysis duration, ultrafiltration volume, ultrafiltration/body weight, therapy of antihypertensive, electrolyte, nutrition state, metabolic bone disease indexes, inflammatory state and serum lipid state were analyzed and compared between the two groups. And multivariate stepwise regression analysis was made between the SBPV(CV and SD)and the above observation parameters.The total water content and distribution was detected by the bioelectrical impedance in81MHD patients. Seventeen normal individuals are as a control group. The SBPV is compared between the dry weight successed patients and not. Total body water(TBW), extracellular fluid (ECW), intracellular fluid (ICW) and E/I are compared between the pre-and post HD in the men and women patients respectively. And then the post-HD ECW, E/I between the patients with properly dry body weight and the healthy controls were compared in the same gender.The31MHD patients with properly dry body weight were divided into intradialytic hypertention, hypotention and stable BP groups. The possible effect factors such as therapy of antihypertensive, metabolic bone disease indexes, electrolyte, nutrition state, inflammatory state, serum lipid state and pulse pressure difference were compared between the groups. The plasma ADMA was detected by ELISA (Enzyme linked immunosorbent assay) method in pre-and post-HD and studyed the correlation between ADMA and the blood pressure change in MHD patientsResults1. The average SBP-CV in intradialysis was8.12±3.16%in81MHD patients. The average DBP-CV was8.29±3.20%. The SBP-CV was normally distributed (P=0.329). The patients were divided into two groups according to the mean value of the SBP-CV:SBP-CV>8.12%group(35patients) and SBP-CV<8.12%group(46patients). Serum creatinine, potassium, Hs-CRP and ALP were higher in high SBPV group than that in low SBPV group (P=0.034,0.005,0.001and0.049respectively). SBP-SD and Hs-CRP were positively related(r=0.499). SBP-CV and Hs-CRP, dialysis vintage were positively related(r=0.464and0.211) by the multivariate stepwise regression analysis.2. The total body water volume and the distribution were detected in81patients.11patients were removed because of unqualified materials. Dry weight successed rate was82.9%(58/70). The SBPV had no siginificant difference between the dry weight successed patients and not(P>0.05). TBW, ECW, and E/I of post-HD were significantly decreased compared to pre-HD(P<0.001) in the female and male patients respectively, but the ICW have no obvious difference(P>0.05). There were no significant difference between the ECW, E/I of the post-HD in the properly dry weight patients and the normal control group (P>0.05, female and male respectively). The decrease value of ECW was positively related with a dehydration volume (r=0.756).3. The plasma ADMA were markedly elevated in the beginning and fell significantly in the end of the HD sessions in MHD patients (3.37±1.48umol/L vs1.71±0.80umol/L). Both before and after HD, the plasma ADMA levels were higher significantly in intradialytic hypotensive patients (4.38±1.56umol/L,2.25±0.83umol/L) than in hypertensive and stable BP patients(2.70±1.18umol/L,1.32±0.60umol/L;2.78±0.88umol/L and1.43±0.56umol/L; P=0.006and0.006). The pulse pressure difference was significantly higher in intradialytic hypertensive patients than that in hypotensive and stable BP patients (62.41±11.57mmHg,47.98±13.30mmHg and44.56±8.30mmHg, P=0.004). ALP, TC, LDL-C and Hs-CRP were higher in hypertensive and hypotensive patients than in stable BP patients (all P<0.05), but there was no significant difference between the hypertensive and hypotensive groups. Multivariate stepwise regression analysis was made between pre-HD ADMA and SBP-CV, we found that them were positively related (r=0.396).Conclusions1. Intradialytic SBPV is positive associated with the inflammatory state and dialysis vintage in the MHD patients.2. Distribution of body fluid of MHD patients is obviously abnormal, mainly the predialysis ECW%is increasing, dialysis dehydration is mainly from ECW. The ICW had no obvious change. The decreased value of ECW was positively related with dehydration volume. There is no correlation between SBPV and dehydration, There is no correlation between SBPV and dry weight is properly or not.3. SBPV is positive associated with plasma ADMA in pre-HD. ADMA are markedly elevated in MHD patients and with a significant fall in the end of the HD sessions. The plasma ADMA level is higher in intradialytic hypotensive patients than that in the hypertensive and stable BP patients.