Danish Hypertension Prevention Project - DHYPP

Essential hypertension, a major health problem worldwide, is a disease generally considered to require life-long treatment. However, evidence suggests that hypertension is caused by specific phenotypic changes caused by a combination of genetic and environmental factors. Thus, in principle, hypertension could be prevented by prevention of these phenotypic changes. Animal data indicate that early treatment that blocks the renin-angiotensin system have long-term effects after treatment withdrawal. The present human study is testing whether early treatment (with the AT1- antagonist) is able to have a persistent effect after stopping treatment.

This is a monocenter, double-blind, randomized, placebo-controlled study in healthy, normotensive (consultation diastolic blood pressure over 2 visits < 85 mmHg) subjects 18 to 36 years of age whose both parents have essential hypertension. The primary objective is to determine whether pharmacological treatment with an angiotensin receptor blocker is able to restrain or delay the progression to hypertension. Secondary objectives are to investigate whether any long-term effect on blood pressure is related to the effect of treatment on renal haemodynamic function, or on the left ventricle mass.

Subjects are recruited by use of hospital registers to identify persons who have received the indication essential hypertension, and are of an age that they may have children of the appropriate age. These persons are then mailed asking if they do have children with a partner who is also hypertensive, and asking permission to contact the children. The diagnosis of hypertension of the parents is checked following evaluation by the physicians who are treating them.

One hundred subjects were randomly assigned to one of two treatment groups: placebo; or candesartan cilexetil, 16 mg, once daily. Before inclusion and after 12 months of treatment glomerular filtration rate, renal vascular resistance, echocardiography and 24-hour blood pressure monitoring were performed. Subjects were evaluated at 0.5, 1, 2, 4, 6 and 10 months to ensure compliance and to control blood pressure. After 12-months of treatment, 24-hour blood pressure monitoring were performed in a scheduled manner over a 10-year period. The primary effect parameter is 24-hour blood pressure measured 10 years after withdrawal of treatment. Interim analyses will be made at 1, 2 and 5 years by an independent data committee. Secondary effect parameters will be numbers on antihypertensive treatment at 2, 5 and 10 years after withdrawal, as well as the effect of treatment on renal vascular resistance and left ventricular mass.

A substudy is comparing renal haemodynamics and genetic profil of the subjects with persons having normotensive parents.