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.