Relationship between blood pressure variability and renal function damage in patient with prehypertension

Objective To investigate the change of blood pressure variability(BPV)and the relationship between serum creatinine(sCr)and BPV in prehypertensive patients,and to explore the effect of BPV on renal function.Methods A total of 180 patients were recruited according to the revised edition 2010 guideline for prevention and treatment of hypertension in China and divided into three groups:60normotensive subjects(NT group),60 prehypertensive patients(PH group)and 60 hypertensive patients(EH group).Ambulatory blood pressure(ABP)parameters were monitored,including the average 24-hour systolic blood pressure(24hSBP),24-hour diastolic blood pressure(24hDBP),daytime systolic blood pressure(dSBP),daytime diastolic blood pressure(dDBP),nighttime systolic blood pressure(nSBP)and nighttime diastolic blood pressure(nDBP).BPV parameters,including 24-hour systolic blood pressure variability(24hSBPV),24-hour diastolic blood pressure variability(24hDBPV),daytime systolic blood pressure variability(dSBPV),daytime diastolic blood pressure variability(dDBPV),nighttime systolic blood pressure variability(nSBPV)and nighttime diastolic blood pressure variability(nDBPV),were determined.The relationship between sCr and BPV were analyzed.Results The concentration of sCr was(69.2±15.5) mol/L,(76.6±14.9) mol/L and(83.7±18.2) mol/L in NT,PH and EH groups,respectively.After adjustment of age,sex,serum lipid and serum glucose with covarianceanalysis,the concentration of sCr in PH group was significantly higher than that in NT group(P0.05),and the concentration of sCr in EH group was significantly higher than that in NT and PH groups(both P0.01).The ABP parameters and nDBP and BPV parameters in PH group were significantly higher than those in NT group(P0.01 or 0.05),and these parameters in EH group were significantly higher than those in NT and PH groups(all P0.01).Multiple linear regression analysis showed that after adjustment of age,sex,body mass index(BMI),serum lipid and serum glucose,sCr was positively correlated with 24 hSBPV in NT group(standard partial regression coefficient was 0.231,P=0.049);sCr was positively correlated with 24 hSBPV,24hDBPV,dSBPV and nSBPV in PH group(standard partial regression coefficient were 0.347,0.248,0.268 and 0.252,respectively,Pvalue were0.001,0.042,0.028 and 0.039,respectively);sCr was positively correlated with24 hSBPV,24hDBPV,dSBPV,dSBPV,dDBPV,nSBPV and nDBPV in EH group(standard partial regression coefficient were respectively 0.381,0.279,0.368,0.272,0.294 and 0.263,P value were respectively 0.001,0.017,0.001,0.021,0.009 and 0.031).Conclusion Obvious abnormality of BPV exist in prehypertensive patients and renal function damage is correlated with BPV.