Neurovascular control in patients with hypertension, cerebrovascular disease and sleep disorders.

Background. 24 hour Ambulatory Blood Pressure Monitoring (ABPM) combined with sleep questionnaires and/or Polysomnography is a useful non invasive tool to study the neurovascular response in different behavioural states. In fact, many conditions during wake (life style, stress, cognitive and physical effort) and sleep state (insufficient sleep, snoring, sleep apnea, autonomic instability, REM behaviour disorder, etc.) may alter the Blood Pressure (BP) circadian pattern, leading to cardio- and cerebrovascular disease. Materials and Methods. BP circadian pattern and Heart Rate (HR) were recorded in three groups of patients ( C-Cerebrovascular 55 pts, 29M, 26F mean age 58.75 ±11, SD- Sleep Disorders 101 pts, 83M, 18F, mean age 54.25 ± 10, H-Hypertensive 37 pts, 12M, 25F, mean age 56.22 ±11). In all patients the ABPM was combined with sleep-wake diary. For a few patients polysomnography was additionally obtained. Results. The results (ANOVA) revealed no statistical difference among the groups for the values of Systolic BP ( C 132.5 ± 14 vs SD 130,8 ±13 vs H 131.8 ± 11 mmHg,) and HR ( C 74,07 ± 9 vs SD 71,8 ± 7 vs H 74,5 ± 7 beat/m). Statistical difference was found for Diastolic BP ( C 74,9 ± 9 vs SD 77,02 ± 9 vs H 73,48 ± 7 mmHg, p ‹ .05). As for age, sex, BMI, SBP, DBP and HR, the Nocturnal Reduction Rate (NRR, an index expressing the day-night BP variations) revealed no statistical difference (Coeff. R di Spearman) among and within the groups. The same index allowed to classify the patients in four subgroups ( Dippers NRR ≥ 10%, NonDippers NRR ‹ 10%, ExtremeDippers NRR ≥20 % and ReverseDippers NRR negative number ‹ 0). The ND type was prevalent in the SD group (41.58%), the RD type in the C group (20%) and the ED type was more rapresented in the H group (21.62%). Discussion. Our results showed that the NRR is low correlated to age, sex, BMI and absolute values of BP and HR, suggesting this index may be more useful in longitudinal studies. The different prevalence of the four subgroups in the three original groups may reflect different autonomic neurovascular responses depending on specific disease.