1100 ADEQUACY OF BLOOD PRESSURE CONTROL IN CHRONIC KIDNEY DISEASE

Background: In essential hypertension (EHT), clinic blood pressure measurement (CBP) misclassifies blood pressure (BP) in patients with white coat hypertension (WCHT) and masked hypertension (MHT). Accurate BP measurement in the chronic kidney disease (CKD) population is important in controlling cardiovascular complications and renal disease progression. The aim of this study was to characterise BP control in CKD population. Methods: 50 EHT and 387 CKD patients underwent CBP, ambulatory BP monitoring and central pressure measurement by pulse wave analysis (PWA). Patients were classified as having controlled hypertension (CHT), sustained hypertension (SHT), WCHT or MHT by comparing CBP to awake ambulatory BP average. BP control in the different CKD stages- stages 1 &2 (CKD-1,2, n = 153), stage 3 (CKD-3, n = 172) and stages 4 and 5 (CKD-4,5, n = 67) were compared with EHT (n = 50). Results: CKD-3 and CKD-4,5 were older than EH and CKD-1,2 (p′ < 0.01). There were no significant differences in the prevalence of CHT, SHT, WCHT or MHT; or type of antihypertensive used between EHT and CKD. Central pulse pressure (CPP) was lower in EHT than CKD-3 and CKD-4,5 (p′ < 0.01). Augmentation index was lower in EHT than all CKD groups (p′ < 0.01). Among the combined CKD groups, patients with CHT had significantly lower central systolic pressure and CPP than patients with SHT, WCHT and MHT (p′ < 0.05). However, central pressure measurements were not significantly different between MHT, WCHT and SHT. Conclusions: CBP misclassifies BP control in CKD and EHT. PWA may identify those patients with CHT but dose not distinguish between SHT, WCHT and MHT