Usefulness of assessing masked and white-coat hypertension by ambulatory blood pressure monitoring for determining prevalent risk of chronic kidney disease: the Ohasama study

Masked hypertension (MHT) is considered to be associated with organ damage, whereas the association of white-coat hypertension (WCHT) with organ damage remains controversial. Using home blood pressure measurements, we have previously reported that MHT is associated with a risk of chronic kidney disease (CKD) compared with sustained normal blood pressure (SNBP), although WCHT was not significantly related to CKD in a general Japanese population. The objective of this study was to examine CKD risk associated with WCHT and MHT as determined by ambulatory blood pressure (ABP) monitoring. Among 1023 residents in the general Japanese population of Ohasama, ABP and casual blood pressure (CBP) levels were recorded and blood and urine samples were collected. CKD was defined as a positive proteinuria and/or estimated glomerular filtration rate <60 ml min−1 per 1.73 m2. Participants were categorized into four groups using daytime ABP of 140/85 mm Hg and CBP of 140/90 mm Hg as cutoff points: SNBP, 60.0%; WCHT, 15.4%; MHT, 15.0%; and sustained hypertension (SHT), 9.6%. Odds ratios (ORs) for prevalence of CKD were calculated using a multiple logistic regression model. Compared with SNBP, risk of CKD was significantly higher in SHT (OR, 2.81; 95% confidence interval (CI), 1.66–4.75; P=0.0001), MHT (OR, 2.29; 95% CI, 1.45–3.63; P=0.0004) and WCHT (OR, 1.67; 95% CI, 1.03–2.71; P=0.0368). CKD was significantly associated with MHT and WCHT on the basis of ABP monitoring compared with SNBP in the general Japanese population.