White-coat hypertension as a risk factor for the development of home hypertension - The Ohasama Study

Background: White-coat hypertension is a condition characterized by elevated blood pressure (BP) in medical settings combined with normal ambulatory-recorded BP or self-measured BP at home (home BP). However, it is unknown whether this condition represents a transient state in the development of hypertension outside medical settings. Methods: We followed up 128 subjects with white-coat hypertension (home BP < 135/85 mm Hg and office BP >= 140/90 mm Hg) for 8 years and compared the risk of progression with home hypertension (home BP >= 135/85 mm Hg or start of treatment with antihypertensive medication) with 649 sustained normotensive subjects (home BP < 135/85 min Hg and office BP < 140/90 min Hg) using data from population-based home BP measurement projects in Japan. Results: During the 8-year follow-up period, 60 subjects (46.9%) with white-coat hypertension and 144 (22.2%) with sustained normotension progressed to home hypertension. The odds ratio of subjects with white-coat hypertension for progression to home hypertension (adjusted for possible confounding factors) was significantly higher than for subjects with sustained normotension (odds ratio, 2.86; P < 001). This association was observed independent of baseline home BP levels. Conclusion: The results from the present 8-year follow-up study demonstrate that white-coat hypertension is a transitional condition to hypertension outside medical settings, suggesting that white-coat hypertension may carry a poor cardiovascular prognosis.