Comparison of microalbuminuria in 2 blood pressure categories of prehypertensive subjects

Background: Subjects with high normal blood pressure (BP: systolic, 130-139 mmHg or diastolic, 85-89 mmHg) have higher cardiovascular risks compared with individuals with normal BP (systolic BP, 120-129 mmHg or diastolic BP, 80-84 mmHg). In the present study the prevalence of microalbuminuria and cardiovascular risk factors, as well as factors that influence microalbuminuria, were assessed in 2 groups of subjects with prehypertension. Methods and Results: Of 2,678 prehypertensive subjects (1,689 men, 989 women), none had a history of diabetes or hypertension. Urine albumin excretion was measured by an immunoradiometric assay in a morning urine sample. The prevalence of microalbuminuria in the high normal BP group was higher than in the normal BP group (4.9% vs 2.8%, p=0.009). Subjects with high normal BP were older, and had higher prevalence of males and metabolic syndrome; larger waist circumference and body mass index, higher levels of triglycerides, fasting blood glucose, uric acid and ferritin, and lower levels of high-density lipoprotein-cholesterol were more common in subjects with high normal BP than in those with normal BP. Multiple logistic regression analysis showed that the high normal BP category had an independently significant association with microalbuminuria (odds ratio=1.692, 95%confidence interval 1.097-2.611). Conclusions: Subjects with high normal BP have greater risk factors for cardiovascular disease, including microalbuminuria, than those with normal BP. Further investigations are needed to ascertain whether more positive treatment strategies for the early prevention of cardiovascular disease might be needed for individuals with high normal BP.