Response to Long-Term Risk in Subjects With White-Coat Hypertension
We thank Obara et al1 for their interest in the results of our analysis of the Pressioni Arteriose Monitorate e Loro Associazioni Study population,2 which expands on the evidence obtained in the Ohasama Study population.3 As mentioned by Ugajin et al,3 in the Ohasama population, white-coat hypertension, as defined by a high office blood pressure (BP) and a normal home BP, was associated with a greater risk of developing sustained (ie, office and home) hypertension as compared with true normotension, that is, the condition in which both office and home BPs were within the normal range. This was the case also in the contest of the larger database and the longer follow-up of the Pressioni Arteriose Monitorate e Loro Associazioni population, with the following additional evidence: (1) white-coat hypertension causes a greater risk of developing sustained hypertension also when defined by a high office and a normal ambulatory BP; (2) the risk of new-onset sustained hypertension is also increased in the opposite condition, that is, the elevation of home or ambulatory BP with a normal office BP, known as “masked hypertension”; and (3) this does not just depend on the fact that, in both white-coat and masked hypertension, the “normotensive” BP is somewhat higher than in true normotension,4 thereby being closer to the cutoff value defining the entrance into the hypertensive range. Somewhat different from the approach used by Ugajin et al,3 in our subjects this was directly documented by the observation that, compared with true normotensive subjects, white-coat and masker hypertensive subjects exhibited a greater increase in out-of-office (home or ambulatory) and office BP, respectively, thereby showing a greater tendency for their initially normal BP to became elevated with time.
We agree that, taken together, these results strongly support the view that white-coat and masked hypertension are by no means innocent conditions, and, indeed, we believe that this conclusion is now undisputable. In addition to the data mentioned by Ugajin et al,3 we wish to remember that, compared with true normotensives, the white-coat and masked hypertensives of the Pressioni Arteriose Monitorate e Loro Associazioni population also showed an increased risk of developing diabetes mellitus.5 Furthermore, in these subjects, the 12-year cardiovascular risk was also greater,4 particularly when fatal and nonfatal events were jointly considered. Thus, we concur with the conclusion of Ugajin et al3 that it would be desirable to periodically measure out-of-office BP and to perform trials investigating the benefit of its therapeutic control. Ideally, measurements should include both ambulatory and home BPs, because their correlation is not high, and their prognostic values and redundant risk are complementary.4,6
Obara T, Ohkubo T, Imai Y. Long-term risk in subjects with white-coat hypertension. Hypertension. 2009; 54: e133.
Mancia G, Bombelli M, Facchetti R, Madotto F, Quarti-Trevano F, Friz HP, Grassi G, Sega R. Long-term risk of sustained hypertension in white-coat or masked hypertension. Hypertension. 2009; 54: 226–232.
Mancia G, Facchetti R, Bombelli M, Grassi G, Sega R. Long-term risk of mortality associated with selective and combined elevation in office, home, and ambulatory blood pressure. Hypertension. 2006; 47: 846–853.
Mancia G. Effective ambulatory blood pressure control in medical practice: good news to be taken with caution. Hypertension. 2007; 49: 17–18.