Blood pressure and left ventricular mass in children and adolescents: the Hypertension in Pregnancy Offspring Study.

The etiology of essential hypertension is still a matter of some speculation. Research concerned with pre-hypertensive mechanisms of human essential hypertension usually includes subjects with either borderline hypertension or with a positive family history of hypertension. High blood pressure and increased left ventricular mass are risk factors for cardiovascular disease in adults. Much information about hypertension and other coronary artery disease risk factors in children and adolescents has been collected in the past two decades, and during the last years new evidence has emerged which indicates that essential hypertension originates early in life. Several studies have suggested that children and adolescents born following hypertensive pregnancies may constitute a risk group for future hypertension. The present study addresses the question concerning the future cardiovascular risk in offspring of women who had hypertension during pregnancy. The subjects in the present study were also studied in the search for early pre-hypertensive mechanisms. Fifty-nine children were studied, their mean age being 12.6 years. Forty-two children were born to mothers who had hypertension during pregnancy and 17 children were born after normotensive pregnancies by mothers who remained normotensive at follow-up 7-12 years after pregnancy. Blood pressure was measured at rest and during physical exercise. Left ventricular mass was calculated from M-mode echocardiogram. Erythrocyte concentrations of sodium and potassium and Na-K-ATPase activity were determined. Perinatal and maternal characteristics were collected from hospital records for all deliveries. Twenty-nine males and 23 females, of the initially studied children, were reexamined after 5.6 years. The present study demonstrates that children whose mothers had hypertension during pregnancy and were hypertensive at follow-up had higher blood pressure than children born following normotensive pregnancies. A familial factor for hypertension was an independent determinant of blood pressure, but not a determinant of left ventricular mass. Children born following hypertensive pregnancies had lower birth weight, shorter gestational period and higher blood pressure at follow-up. There was no relationship between birth weight and blood pressure in these children, but there were associations between maternal blood pressure during pregnancy and birth weight as well as blood pressure at follow-up. The difference in blood pressure persisted as the children matured. Particularly the children whose mothers had hypertension during pregnancy and were hypertensive at follow-up maintained their rank with regard to blood pressure and left ventricular mass during adolescence.(ABSTRACT TRUNCATED AT 400 WORDS)