The letter by Gupta brings up several interesting points. While it is true that not all patients with IOH, or white coat hypertension, have sustained hypertension (by definition) or the presence of left ventricular diastolic dysfunction, the data from the study by Grandi et al1 indicate that many of these patients do have physiologic (vascular) changes that may be too early to detect on a routine evaluation. Obviously, again by definition, the 20% or more of patients with IOH have normal BP levels outside the physician's office. I would remind Gupta and colleagues that almost all of the data that estimate risk from the long-term well-randomized controlled trials have been based on casual BP measurements. A casual or office BP reading higher than 140/90 mm Hg indicates a poorer prognosis than readings below that level. Also, to repeat what I said in my editorial,2 all the data on benefit have been determined by office or casual BP readings: persons who achieve lower BP levels have the best outcome. The argument that patients with IOH on one occasion will have it again on another indicates that these are probably the individuals who will have vascular changes that are undetectable; these individuals probably should be treated. Subsequent observations find that about 10% to 12% of the persons who are hypertensive on the first visit become normotensive on subsequent testing; they should just receive follow-up.
Moser M. ABPM Is Valuable for the Management of Hypertension—Reply. Arch Intern Med. 2002;162(13):1531-1532. doi: