[Morning rise of systolic blood pressure (by 24-hour ambulatory monitoring) and platelet aggregability in essential hypertension patients].
OBJECTIVE
To investigate the relationship between platelet aggregability (PA) and parameters of blood pressure (BP) in patients with essential hypertension (EH).


METHODS
We analyzed 24-h BP recordings (SL-90207, 15-min day and 30 min night time intervals) of 47 hospitalized males with mild to moderate EH (mean age 48 +/- 1 years) to assess the following parameters: mean 24-h, awake (Aw) and nighttime (N) systolic (S) and diastolic (D) BP. We assessed the morning rise (MR) of BP using the new index: a relative morning rise of systolic BP-RMRSBP--(max value of SBP from 6 am to 12 am/mean asleep SBP) x 100%. The kinetics of mean aggregate size (MAS) changes was studied with aggregation analyzer model (230LA Biola Ltd., Russia). The following parameters were used for estimation of platelet aggregability: a relative increase in MAS 2 min after beginning of sample stirring--for spontaneous aggregation (SPA) and the maximum increase in the light transmission for 0.5 microM ADP-induced aggregation (ADPI-PA). The patients were divided into two groups according to the median value of RMRSBP: group 1 (n = 25, RMRSBP < 121%) and group 2 (n = 22, RMRSBP > 121%). The differences in estimated parameters were tested by Student two tailed t-tests and presented by M +/- SE. P < 0.05 was considered statistically significant.


RESULTS
No significant differences have been found between the groups by mean age, body mass index, duration of arterial hypertension, mean 24-h, awake DBP and SBP. Statistically significant differences have been found between groups by SPA, ADPI-PA, night SBP, night DBP, RMRSBP, RMRDBP. In group 2 there was a correlation between RMRSBP and SPA, but not in group 1.


CONCLUSIONS
The morning rise of systolic BP is associated with an increase of ADP-induced and spontaneous platelet aggregability in the patients with mild to moderate essential hypertension and apparently that association is more pronounced at high values of morning BP (more than 20% from mean nocturnal values of SBP).
Oshchepkova
E V
EV
Lazareva
N V
NV
Filatova
L V
LV
Zelveian
P A
PA
Arabidze
G G
GG
D000328:Adult; D001792:Blood Platelets / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology*; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology*; D011379:Prognosis; D012307:Risk Factors