Do borderline hypertensive patients have labile blood pressure?

The 24-hour patterns of ambulatory blood pressure were investigated in borderline (labile) hypertensive patients (office blood pressures fluctuating about 140/90 mm Hg). Sixty-three patients (21 normotensive, 21 borderline hypertensive, and 21 fixed hypertensive) had blood pressures recorded every 7.5 to 15 minutes using noninvasive automatic recorders. The mean 24-hour blood pressures (normotensive, 115 +/- 14/74 +/- 12 mm Hg; borderline hypertensive, 127 +/- 16/81 +/- 13 mm Hg; fixed hypertensive, 143 +/- 17/91 +/- 12 mm Hg) were significantly different from each other (p less than 0.005), but the standard deviations were not significantly different. The percentages of elevated blood pressures on the 24-hour recordings of the borderline hypertensive patients were intermediate between those of the normotensive and fixed hypertensive patients, but within the borderline group there was a broad range in percentage of elevated blood pressures (7.9% to 81.2%). Thus, borderline hypertensive patients have blood pressures no more labile than those in normotensive or fixed hypertensive patients, but because of their broad range of percentage of elevated blood pressures, their pressures are best evaluated with multiple measurements.