Increased cardiovascular risk of treated white coat and masked hypertension in patients with diabetes and chronic kidney disease: the HONEST Study

The prognostic implications of treated white coat hypertension (WCH) and masked hypertension (MH) in patients with diabetes mellitus (DM) or chronic kidney disease (CKD) are not well documented. Using data from the HONEST study (n=21 591), we investigated the relationships between morning home systolic blood pressure (MHSBP) or clinic systolic blood pressure (CSBP) and cardiovascular (CV) risk in hypertensive patients with and without DM or CKD receiving olmesartan-based antihypertensive therapy. The study included 4426 DM patients and 4346 CKD patients at baseline who had 101 and 87 major CV events, respectively, during the follow-up. Compared with well-controlled non-DM patients (MHSBP <135 mm Hg; CSBP <140 mm Hg), DM patients with WCH (MHSBP <135 mm Hg; CSBP ⩾140 mm Hg), MH (MHSBP ⩾135 mm Hg; CSBP <140 mm Hg) or poorly controlled hypertension (PCH) (MHSBP ⩾135 mm Hg; CSBP ⩾140 mm Hg) had significantly higher CV risk (hazard ratio (HR), 2.73, 2.77 and 2.81, respectively). CV risk was also significantly increased in CKD patients with WCH, MH and PCH (HR, 2.14, 1.70 and 2.20, respectively) compared with well-controlled non-CKD patients. Furthermore, DM patients had significantly higher incidence rate than non-DM patients of MHSBP ⩾125 to <135 mm Hg (HR, 1.98) and ⩾135 to <145 mm Hg (HR, 2.41). In conclusion, both WCH and MH are associated with increased CV risk, and thus control of both MHSBP and CSBP is important to reduce CV risk in DM or CKD patients. The results also suggest that even lower MHSBP (<125 mm Hg) may be beneficial for DM patients, although this conclusion is limited by the small number of patients.