Background. Insufficient night-time reduction of blood pressure (BP) and night hypertension are associated with an increased risk of death regardless of the average daily BP. The study of daily BP profiles is very relevant in patients with hypertension of different age categories due to the high risk of thrombotic complications.
 Aim: of the study was to determine the peculiarities of ambulatory blood pressure monitoring (ABPM) indices in middle-aged and elderly hypertensive patients depending on the daily BP profile.
 Materials and methods. ABPM indicators were determined in 125 patients who were divided into 2 groups. 1st group (n=82) – middle-aged hypertensive patients (45-59 years old); 2nd group (n=43) – elderly hypertensive patients (60-74 years old). In the groups of middle-aged and elderly subjects 2 groups of daily BP profiles were distinguished: "dipper" and "non-dipper".
 Indices of ABPM were determined using a portable recorder ABPM-04 (company "Meditech", Hungary). Measurements of BP were performed every 15 minutes during the day (from 6 to 22 hours) and every 30 minutes at night (from 22 to 6 hours). We determined the following indices: the average daily systolic BP (SBP) (mm Hg), the average daly diastolic BP (DBP) (mm Hg), the average BP (mm Hg); the maximal daily SBP (mm Hg), the maximal daily DBP (mm Hg). The daily index (DI) was also calculated − the percentage of BP decrease at night compared to daytime BP calculated in % DI of SBP, DI of DBP, DI of average BP.
 Results. The baseline BP level in the average daily SBP and DBP in middle-aged patients of dipper group was significantly higher by 49,6% and corresponded to 155,9±12,0 mm Hg (p<0,001) and 50,4% and was 97,3±6,1 mm Hg (p<0,01). Similar results are observed in the average BP and the maximal daily SBP and the maximal daily DBP values which were significantly higher than the control group by 21,5% (p<0,05) and equaled 110,0±3,6 mm Hg and 21,3% and amounted to 176,3±23,5 mm Hg (p<0,05) and 23,6% and amounted to 117,0±19,2 mm Hg (p<0,05). The baseline BP level in the average daily and maximal SBP, the average daily DBP and the average BP in patients of non-dipper group was significantly higher by 50,8% (p<0,01) and corresponded to 157,1±12,9 mm Hg and 27,4% and equal to 176,9±24,0 mm Hg (p<0,05), 63,8% and amounted to 106,0±1,0 mm Hg (p<0,05) and 44% and was 124,3±6,8 mm Hg (p<0,05) too. In the surveyed elderly patients only the average daily DBP was significantly different from the corresponding control indicator and was lower by 21,4% (p<0,05) and amounted to 91,5±0,7 mm Hg in dipper and 23,1% (p<0,01) and was 93,5±0,7 mm Hg in non-dipper group.
 Conclusion. Non-dipper group predominates in the structure of daily BP rhythm in elderly hypertensive patients (62,8% versus 37,2%). The average BP decreases in elderly patients of non-dipper group by 11,1% (p<0,05) reliably to patients of middle age.