Abstract: Objective To explore the differences of intradialytic blood pressure variability(BPV)with age and the relevant influencing factors in maintenance hemodialysis(MHD)patients.Methods A total of 102 MHD patients were divided into three groups of young group(<45 years,n=32),middle-aged group(45-60 years,n=26)and elderly group(≥60 years,n=44).BPV was expressed by standard deviation(SD)and coefficient of variation(CV)of multiple blood pressure readings.The differences of intradialytic BPV were compared among three groups and the relevant factors were analyzed.Results As compared with young group,the proportion of diabetes mellitus increased markedly and the levels of serum creatinine and albumin declined obviously in middle-aged and elderly groups(P<0.05).The level of high-sensitivity C-reactive protein was higher in elderly group than that in young group(P<0.05).As compared with young and middle-aged groups,the serum level of phosphorus was lower in elderly group(P<0.05).No significant differences existed in hemoglobin,intact parathyroid hormone,total calcium,Kt/V or the proportion of taking three or four kinds of antihypertensive drugs among three groups(P>0.05).The mean pre-dialysis systolic blood pressure(SBP),intradialytic SBP-SD and SBP-CV were significantly higher in middle-aged and elderly groups than those in young group(P<0.05).The pre-dialysis and intradialytic diastolic blood pressure(DBP)were significantly lower in elderly group than those in young and middle-aged groups(P<0.05).As compared with middle-aged group,ultrafiltration volume decreased markedly in elderly group(P<0.05).No significant differences existed in intradialytic SBP or DBP-CV among three groups(P>0.05).Multivariate stepwise regression showed that diabetes and females were positively correlated with intradialytic SBP-CV while serum albumin was negatively correlated with intradialytic SBP-CV(P<0.05).Conclusion Intradialytic systolic blood pressure variability is significantly higher in middle-aged and elderly MHD patients than that in young MHD counterparts.And intradialytic BPV may be reduced by a higher serum level of albumin.