Power Of Systolic Blood Pressure Research Articles

Sequential spectral analysis of 24-hour blood pressure and pulse interval in humans.

Blood pressure and pulse interval are characterized not only by erratic variations but also by rhythmic fluctuations at low-, mid-, and high-frequency (0.025-0.07, 0.07-0.14, and 0.14-0.35 Hz, respectively). However, information on these phenomena has largely been derived from analysis of short-term recordings taken in standardized laboratory conditions. In seven normotensive and 10 untreated mild essential hypertensive subjects, power spectrum analysis was performed on the intra-arterial blood pressure and pulse interval signal collected over a 24-hour period using the fast Fourier transform algorithm and splitting the recording into contiguous segments of 256 beats. About 70% of the segments were suitable for the analysis; the segments excluded for a nonstationary signal amounted to only 30%. All powers were characterized by a high segment-to-segment variability, but in each subject the mid- and high-frequency powers of diastolic blood pressure and the mid-frequency power of systolic blood pressure were markedly reduced during the night as compared with the daytime period, whereas the opposite occurred for the low- and high-frequency powers of the pulse interval. Over the 24-hour period, mid- and high-frequency powers of blood pressure were positively correlated to each other, but both accounted for less than 25% of the 24-hour blood pressure variance. No difference between mean normalized power values of normotensive and hypertensive subjects was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Determinants of blood pressure in 7th grade Jerusalem school children.

The determinants of blood pressure level were analyzed in a group of 1154 Jerusalem school children aged 12. After controlling for age, significant differences in blood pressure measurements were found between three groups: boys, pre-menarche girls and post-menarche girls. A comparison of the means of selected biological variables showed that girls who have reached menarche have levels of systolic blood pressure, weight, height and Quetelet's index higher than boys and pre-menarche girls. However, levels of triceps skinfold thickness and pulse rate were similar in the two groups of girls and higher than in boys. Using multiple regression analysis, we found that much of the variance (boys 29%, post-menarche girls 21% and pre-menarche girls 15%) of systolic blood pressure could be explained by a combination of biological variables (Quetelet, pulse rate, triceps skinfold thickness and height) while these variables explained a much smaller proportion (boys 12%, post-menarche girls 17% and pre-menarche 9%) of diastolic blood pressure variance. The predictive power of systolic blood pressure by the measured biological variables was higher in boys than in girls. However, diastolic blood pressure was better predicted by the biological variables in the group of girls with menarche than in other groups. Elevated blood pressure was observed in 3.2% of the examined children. High values for Quetelet's index were observed in 6.4%. The prevalence of elevated measurements of blood pressure and Quetelet's index were significantly higher in girls with menarche. Among children aged 12, the association between sociodemographic characteristics and blood pressure level was weak, as measured in multiple regression analysis.