The prognostic significance of white coat hypertension (WHC) and morning hypertension remains controversial in patients with chronic kidney disease (CKD). We explored the clinical impact of WHC and morning hypertension in CKD patients using ambulatory blood pressure monitoring (ABPM).Design and method:
The presence of end-organ damage (any of the followings - coronary artery calcium score > 400, presence of internal carotid artery plaque, decreased ankle brachial index < 0.9, or increased brachial-ankle pulse wave velocity > 1800 cm/sec) was assessed in 459 consecutive CKD patients. Patients were classified into 4 groups - normotensive, WCH (Office blood pressure (BP) = 140/90 mmHg & ABPM < 130/80 mmHg), masked hypertension (Office BP < 140/90 & ABPM = 130/80 mmHg), or sustained hypertension. The results were compared between groups.Results:
Mean age was 59 ± 12years, and 63.2% were male. There were 143 normotensive patients (31.2%), 28 patients with WCH (6.1%), 132 patients (28.8%) with masked hypertension, and 156 patients (34.0%) with sustained hypertension. Misclassification of BP control (WCH or masked hypertension) at the office was observed in 34.9% of patients with CKD. Interestingly, although morning hypertension was more frequently observed in normotensive patients or WCH patients compared with masked or sustained hypertension patients (43.4% vs 56.3%, p = 0.035), it was not associated with end-organ damage (p = 0.054). Compared with normotensive group, end-organ damage was more frequently observed in patients with masked hypertension or sustained hypertension (35.7% vs 59.8% or 76.9%, all p < 0.001). However, the presence of end-organ damage was not significantly different between normotensive group and WCH group (35.7% vs 39.3%, p = 0.715).Conclusions:
Neither morning hypertension nor WCH was associated with the risk of end-organ damage in CKD patients, compared with high prevalence of end-organ damage in masked or sustained hypertension group. Because BP measurement at the office misclassifies the BP control about 1 in 3 patients with CKD, monitoring with ABPM could be useful to guide appropriate treatment in CKD patients.