Differences between office and 24-hour blood pressure control in hypertensive patients with CKD: A 5,693-patient cross-sectional analysis from Spain.

BACKGROUND Previous studies have examined control rates of office blood pressure (BP) in chronic kidney disease (CKD). However, recent evidence suggests major discrepancies between office and 24-hour BP values in hypertensive populations. This study examined concordance/discordance between office- and ambulatory-based BP control in a large cohort of patients with CKD. STUDY DESIGN Cross-sectional. SETTING & PARTICIPANTS 5,693 hypertensive individuals with CKD stages 1-5 from the Spanish ABPM (ambulatory BP monitoring) Registry. PREDICTORS Thresholds of 140/90 and 130/80 mm Hg for office BP and 24-hour ambulatory BP, respectively. Age, sex, body mass index, waist circumference, hypertension duration, kidney measures, diabetes, dyslipidemia, target-organ damage, and cardiovascular comorbid conditions. OUTCOMES Misclassification of BP control as "white-coat" hypertension (office BP ≥140/90 mm Hg, 24-hour BP <130/80 mm Hg) or masked hypertension (office BP <140/90 mm Hg, 24-hour BP ≥130/80 mm Hg). MEASUREMENTS Standardized office-based BP and 24-hour ABPM. RESULTS Mean age was 61.0 ± 13.9 (SD) years and 52.6% were men. The proportion with white-coat hypertension was 28.8% (36.8% of patients with office BP ≥140/90 mm Hg) and that of masked hypertension was 7.0% (but 32.1% of patients with office BP <140/90 mm Hg). Female sex, aging, obesity, and target-organ damage were associated with white-coat hypertension; aging and obesity were associated with masked hypertension. Only 21.7% and 8.1% of the CKD population had office BP <140/90 and <130/80 mm Hg, respectively. In contrast, 43.5% of individuals had average 24-hour BP <130/80 mm Hg. LIMITATIONS Cross-sectional design, longitudinal associations cannot be established. CONCLUSIONS Misclassification of BP control at the office was observed in 1 of 3 hypertensive patients with CKD. Ambulatory-based control rates were far better than office-based rates. Nevertheless, the burden of uncontrolled ambulatory BP and misclassification of BP control at the office constitutes a call for wider use of ABPM to evaluate the success of hypertension treatment in patients with CKD.