Background: Blood pressure (BP) control is the mainstay of stalling the progression of cardiorenal disease, yet the performance characteristics of BPs obtained in the clinic (CBPs) by routine or standardized methods or at home (HBP) in diagnosing hypertension or assessing its control are unknown.
Methods: Two hundred thirty-two patients (20% black; 4% women; mean age, 67 years; 35% with diabetes) with chronic kidney disease (CKD) underwent a single 24-hour ambulatory BP (ABP) monitoring (ABPM) and concomitant recording of CBP and HBP for 1 week. Hypertension is defined as systolic BP of 130 mm Hg or greater or diastolic BP of 80 mm Hg or greater on average awake 24-hour ABPM.
Results: Average ABP was 135.2 +/- 15.9/75.6 +/- 11.0 mm Hg. Thirty-five percent of patients had isolated systolic hypertension; 3%, isolated diastolic hypertension; 27%, combined systolic and diastolic hypertension; and 35%, normotension or well-controlled BP. The prevalence of "white-coat effect" was estimated as 28% to 30% by means of CBPs and 24% by means of HBPs. Well-controlled BP in the clinic, but poorly controlled BP by means of ABPM, masked hypertension, was seen in 26% to 29% by means of CBPs, but only 13% with HBP monitoring.
Conclusion: In patients with CKD, HBP is superior in reducing the misclassification of hypertension caused by the white-coat effect and masked hypertension commonly seen with CBPs. An average HBP of approximately 140/80 mm Hg appears to be the best correlate of hypertension defined by means of ABPM.