Consequence of Masked Hypertension in Treated Hypertensive Outpatients: 1-Year Follow-Up Study

Since masked hypertension (MHT) is high risk for cardiovascular disease, the importance of home blood pressure (HBP) control is emphasized. The aim of this study was to investigate the prevalence of MHT in the treated hypertensives and the consequence of their BP control status after a 1-year follow up period. Subjects are 262 treated hypertensive outpatients. We assessed BP control status, background characteristics, and antihypertensive drugs in both 2008 and 2009. Clinic BP (CBP) and morning HBP in 2008 were 133 +/- 12/73 +/- 9 mmHg and 132 +/- 11/77 +/- 8 mmHg, which significantly decreased to 129 +/- 11/70 +/- 10 mmHg and 130 +/- 10/76 +/- 8 mmHg in 2009, respectively (p < 0.01). The patients with sustained hypertension (SHT) decreased from 17.9% in 2008 to 6.9% in 2009. Thirty-four percent of SHT patients in 2008 turned out to be MHT and another 34.0% belonged to normotension (NT) in 2009. Among 79 MHT patients in 2008, 62.0% remained as MHT, while 32.9% turned out to be NT in 2009. The sustained MHT patients were more male and showed a higher prevalence of habitual alcohol intake. Nighttime dosing of antihypertensive drugs and the addition of diuretics were major causes of improving morning HBP. Results suggest that one-third of MHT patients showed the improvement of HBP after the 1-year follow-up period. Not only intensive antihypertensive treatment with the appropriate use of diuretics, but also the encouragement of lifestyle modification including alcohol restriction, seems to be important to the management of MHT.