AMBULATORY AND HOME BLOOD-PRESSURE NORMALITY IN THE ELDERLY - DATA FROM THE PAMELA POPULATION

To determine ambulatory blood pressure (BP) means and distributions in an elderly population, we studied a random sample of 800 subjects str atified by sex and representative of residents aged 65 to 74 years of the city of Monza. Participation was 50%. Measurements consisted of cl inic BP (average of three measurements with mercury sphygmomanometry), home BP (average of morning and evening measurements with a semiautom atic device), and ambulatory BP (SpaceLabs 90207). Clinic BP was obtai ned before and after home and ambulatory BP measurements. In normotens ive and untreated hypertensive subjects (n=248), clinic, home, and amb ulatory BPs were significantly related (P<.001). The means of the clin ic BPs obtained on consecutive days were very similar and markedly hig her than 24-hour average BP (+25 mm Hg systolic and +10 mm Hg diastoli c, P<.001). Nighttime BP was markedly less than daytime BP (-14 and -1 3 mmHg, P<.001), whereas home BP values occurred approximately midway between clinic and 24-hour average BP values. Only minor differences e xisted between data in men and women, and the differences in clinic, h ome, and ambulatory BP values occurred in both normotensive and untrea ted hypertensive subjects. All BPs were similar in the untreated and t reated hypertensive groups. Thus, as previously reported in subjects y ounger than 65 years, in the elderly fraction of the population, 24-ho ur average BP is much lower than clinic BP. The upper limit of normali ty for 24-hour average BP (calculated as the value corresponding to 14 0/90 mm Hg clinic BP) is about 120 Mn Hg systolic and 76 mm Hg diastol ic. At variance with data from younger subjects, home BP in the elderl y is higher than 24-hour average BP. However, similar to data from you nger subjects, clinic, home, and ambulatory BPs are higher in treated hypertensive than normotensive elderly subjects, indicating that in hy pertensive elderly subjects, antihypertensive treatment does not commo nly achieve full BP control both inside and outside the clinic environ ment.