Variation Of Ambulatory Blood Pressure In Hypertensive CKD Patients

Objectives:To evaluate the feature of hypertensive CKD patients’ blood pressure with both office blood pressure(OBP) measurement and ambulatory blood pressure monitoring(ABPM). To find the correlation between OBP/ABPM and left ventricular hypertrophy with hypertensive CKD patients’ echocardiography. Compare OBP and ABPM to find which one is superior in monitoring CKD patients’ blood pressure.Methods:174 CKD inpatients from the Nephrology Department of the Second Affiliated Hospital of Kunming Medical University were studied during the period of July 2014 to December 2015. They were divided into 3 groups:CKD1-2 group, CKD3-4 group, CKD5 group. Their basic information and the data of their laboratory tests, office blood pressure, ambulatory blood pressure and echocardiography were collected. The following were analyzed:basic information, office blood pressure, ambulatory blood pressure, circadian patterns of blood pressure, control rate of blood pressure, differences between OBP and ABPM, echocardiography and the correlation between OBP/ABPM and left ventricular hypertrophy.Results:1. CKD patients’office blood pressure and ambulatory blood pressure increased as their renal function declined. The office blood pressure, daytime ambulatory blood pressure, nighttime ambulatory blood pressure,24h ambulatory blood pressure of CKD5 group were higher than CKD 1-2 group (P<0.05). CKD patients’blood pressure variation coefficient decreased as their renal function declined. The daytime ambulatory blood pressure variation coefficient, nighttime ambulatory blood pressure variation coefficient,24h ambulatory blood pressure variation coefficient of CKD5 group were lower than CKD1-2 group (P<0.05).2. There was no significant difference between office systolic blood pressure (SBP) and daytime ambulatory SBP (P=0.234), office SBP was higher than nighttime ambulatory SBP (P<0.001) and 24h ambulatory SBP (P=0.032). Office diastolic blood pressure (DBP) was higher than daytime ambulatory DBP (P=0.030), nighttime ambulatory DBP (P<0.001) and 24h ambulatory DBP (P=0.001).3.74.1% CKD patients had abnormal ambulatory patterns as nondipping or reverse dipping, there was no significant difference between 3 CKD groups (x2=1.14, P=0.57).78.9% patients in CKD5 group had abnormal ambulatory patterns, there was no significant difference between non-dialysis group, peritoneal dialysis group and hematodialysis group.4. The overall control rate of daytime ambulatory SBP was 43.3%, overall daytime ambulatory DBP control rate was 59.6%, overall nighttime ambulatory SBP control rate is 29.2%, overall nighttime ambulatory DBP control rate is 31.5%. The overall control rate of CKD patients’ blood pressure decreased as their renal function declined. The daytime ambulatory SBP control rate, nighttime ambulatory SBP control rate and 24h ambulatory SBP control rate of CKD5 group were lower than CKD 1-2 group (P<0.05). The daytime ambulatory DBP control rate and 24h ambulatory DBP control rate of CKD5 group were lower than CKD 1-2 group (P<0.05). There was no significant difference in nighttime ambulatory DBP control rate between 3 CKD groups (x2=3.98, P=0.136).5. The interventricular septum thickness (IVST) and the left ventricular posterior wall thickness (LVPWT) of CKD5 group were thicker than CKD 1-2 group (P<0.01). Furthermore, the left ventricular end diastolic dimension, left atrium dimension, aorta, right atrium dimension, main pulmonary artery and right ventricular outflow tract of CKD5 group were all larger than CKD 1-2 group (P<0.05). The ejection fraction of CKD5 group was lower than CKD 1-2 group (P<0.05). Both P/ST and LVPWT had positive correlation with OBP and ABPM (P<0.05), mainly correlated with SBP (P<.05). ABPM has superior correlations with IVST and LVPWT.Conclusions:1. CKD patients’ blood pressure level increased as their renal function declined, and became harder to lower. Their blood pressure control rate became worse as well, especially the nighttime ambulatory blood pressure control rate. 2. CKD patients had early abnormal ambulatory patterns and the prevalence of abnormal ambulatory patterns in them was very high.3. OBP could only give limited data of daytime blood pressure, while ABPM could perfectly record both detailed daytime blood pressure and nighttime blood pressure.4. CKD patients’ left ventricular enlarged and heart function deteriorated as their renal function declined. ABPM is a more accurate predictor of left ventricular hypertrophy than OBP.5. ABPM could measure CKD patients’ blood pressure and circadian patterns better than OBP, which might lead to more aggressive antihypertensive regimen and affect the timing of dosing.