Disparate Estimates of Hypertension Control From Ambulatory and Clinic Blood Pressure Measurements in Hypertensive Kidney Disease

Abstract

Abstract-Ambulatory blood pressure (ABP) monitoring provides unique information about day-night patterns of blood pressure (BP). The objectives of this article were to describe ABP patterns in African Americans with hypertensive kidney disease, to examine the joint distribution of clinic BP and ABP, and to determine associations of hypertensive target organ damage with clinic BP and ABP. This study is a cross-sectional analysis of baseline data from the African American Study of Kidney Disease Cohort Study. Masked hypertension was defined by elevated daytime (Ն135/ 85 mm Hg) or elevated nighttime (Ն120/70 mm Hg) ABP in those with controlled clinic BP (Ͻ140/90 mm Hg); nondipping was defined by a Յ10% decrease in mean nighttime systolic BP; reverse dipping was defined by a higher nighttime than daytime systolic BP. Of the 617 participants (mean age: 60.2 years; 62% male; mean estimated glomerular filtration rate: 43.8 mL/min per 1.73 m 2 ) with both clinic BP and ABP, 498 participants (80%) had a nondipping or reverse dipping profile. Of the 377 participants with controlled clinic BP (61%), 70% had masked hypertension. Compared with those with controlled clinic BP or white-coat hypertension, target organ damage (proteinuria and left ventricular hypertrophy) was more common in those with elevated nighttime BP, masked hypertension, or sustained hypertension. In conclusion, clinic BP provides an incomplete and potentially misleading assessment of the severity of hypertension in African Americans with hypertensive kidney disease, in large part because of increased nighttime BP. Whether lowering nighttime BP improves clinical outcomes is unknown but should be tested given the substantial burden of BP-related morbidity in this population.

Clinical Correlates of Ambulatory BP Monitoring among Patients with CKD

“…The prevalence of MHT varies considerably among different reports: Ohkubo et al (35). The percentage of MHT in this study was relatively high compared with these previous reports except for the African American Study of Kidney Disease and Hypertension.…”

Masked Hypertension and Elevated Nighttime Blood Pressure in CKD

“…The prevalence of masked hypertension was similar in CRIC participants when compared with other cohorts of patients with CKD, such as in the African American Study of Kidney Disease and Hypertension Cohort Study and the CKD Japan Cohort, at 43% and 31% respectively (9,(27)(28)(29). However, in a meta-analysis by Agarwal et al and a crosssectional study from Spain, masked hypertension was present in less than 10% of CKD patients (30,31).…”

“…Earlier studies of CKD cohorts have shown an increased risk for masked and sustained hypertension with elevated urine protein, but analyses were unadjusted or obtained from small cohorts (9,27,33). In CRIC, masked hypertension was associated with low eGFR, and masked and sustained hypertension were associated with elevated urine protein, independent of other risk factors.…”

“…Among black Americans, masked hypertension was associated with proteinuria and LVH, and elevated ABP was associated with increased risk for cardiovascular events overall and renal events in those with controlled clinic BP (9,10). In a study of 217 veterans with CKD, ABP was a stronger predictor of ESRD and death than clinic BP; similarly, among 436 Italian patients with CKD, elevated ambulatory daytime and nighttime BP but not clinic BP were associated with increased risk for renal and cardiovascular events (40,41).…”

“…Less is known about masked and white-coat hypertension in patients with CKD because the majority of studies evaluating ABP have been conducted in the general population. Small studies in participants with CKD have reported that masked and sustained hypertension are associated with increased rates of left ventricular hypertrophy (LVH), proteinuria, and cardiovascular and renal events (9)(10)(11).…”