Abstract 2994: Treatment of White Coat Hypertension and Masked Hypertension by Bedtime Sympathetic Blockades; the Reduction of Urinary Microalbuminuria is More Strongly Correlated with Home Blood Pressure Level: Subanalysis of the Japan Morning Surge Study (JMS) - 1
Objectives: Home blood pressure (BP) is reported to give a better prediction of cardiovascular (CV) risk than office BP. Patients with masked hypertension (MHT) are thought to have a higher-risk than predicted by office BP, while those with white coat hypertension (WCHT) have a relatively low risk. There are few data showing whether treatment of MHT and WHT reduce hypertensive target organ damage.
Methods: We enrolled 611 outpatients with elevated morning systolic BP (SBP ≥ 135 mmHg) in self-measured BP monitoring to the JMS-1 study (multicenter, open-label, randomized control study). Patients assigned to the treatment group (Tx.) were prescribed doxazosin 1– 4 mg at bedtime, and an additional beta-blocker if needed, to control morning SBP (< 135 mmHg). Patients in the control group were continued on their baseline antihypertensive medications. Urinary albumin excretion ratio (UAR) was measured at baseline and 6 months of the study. Home SBP was defined as mean morning and evening SBP.
Results: There were 64 patients with MHT [home SBP (HSBP) ≥ 135mmHg and clinic SBP (CSBP) ≥ 140mmHg], and 77 with WCHT (HSBP < 135mmHg and CSBP ≥ 140mmHg). In the patients with MHT, HSBP and CSBP were reduced by Tx., and the reduction was more significant in HSBP (HSBP; −10.9 vs. −1.7 mmHg, P = 0.004, CSBP; 3.0 vs. 12.6 mmHg, P = 0.045). UAR tended to reduce in the Tx. (−5.0 vs. 6.4 g/gCr, P = 0.057). The reduction of UAR was correlated with the reduction of HSBP (HSBP; r = 0.334, P = 0.007, CSBP r = 0.118, P = 0.355). In the patients with WCHT, HSBP and CSBP were reduced by Tx., but the reduction was more significant for CSBP (HSBP; −4.8 vs. 0.3 mmHg, P = 0.045, CSBP; −19.5 vs. −8.3 mmHg, P = 0.002). UAR was significantly reduced in the Tx. (−4.1 vs. 0.1 g/gCr, P = 0.015); however, the reduction of UAR was more significantly correlated with HSBP than clinic SBP (home SBP; r = 0.390, P < 0.001, clinic SBP; r = 0.256, P = 0.025).
Conclusion: Bedtime sympathetic blockade predominantly reduced HSBP in MHT and CSBP in WCHT, but reduction of UAR was more significantly correlated with changes of home BP in both MHT and WCHT, indicating that treatment based on home BP rather than clinic BP may be more effective at reducing target organ damage in the kidneys.