Overestimation of Diastolic Blood Pressure in the Elderly

Indirect sphygmomanometric blood pressure measurement is the established method of diagnosing and monitoring hypertension, but it may overestimate the true blood pressure in certain elderly patients leading to unnecessary or excessive treatment. The authors studied 36 elderly (aged 60 years or older) hypertensive men and compared direct intraarterial diastolic blood pressure (DBP) measurements with indirect DBP measurements obtained concurrently by a standard mercury sphygmomanometer and also by an automatic blood pressure recorder to: assess the presence and degree of overestimation of DBP by indirect cuff measurement, and evaluate an alternative noninvasive method. The difference between sphygmomanometric and intraarterial DBP was 10 mmHg or greater in 14 of 36 patients, whereas that between the automatic recorder and intraarterial DBP was 10 mmHg or greater in 14 of 36 patients, whereas the between the automatic recorder and intraarterial DBP was 10 mmHg or greater in only three of 36 patients (P less than 0.05). Fourteen patients (39%) had a DBP of greater than or equal to 90 mmHg by the mercury sphygmomanometer compared with five patients (14%) by intraarterial measurement (P less than 0.05); only seven patients (19%) had a DBP of greater than or equal to 90 mmHg by the automatic recorder (P = .7). Thus, in the authors' patient population: indirect sphygmomanometer overestimated the frequency of elevated DBP by nearly threefold compared with intraarterial measurements, and the automatic recorder closely approximated intraarterial values offering a more accurate, noninvasive measure of DBP in the elderly.