Subclinical target organ damage in normotensive and prehypertensive patients.

Prehypertension is a risk factor for the development of hypertension and other cardiovascular diseases. The objective of this study was to evaluate for the evidence of subclinical target organ damage in two groups of subjects without hypertension.

This was a prospective cross-sectional study. Subjects seeking care for various clinical conditions in the hospital were invited for the survey. The subjects' were divided in to two groups according to their blood pressure: prehypertension (systolic blood pressure 120 to 139 mm Hg or diastolic blood pressure, 80 to 89 mm Hg) and normotension (systolic blood pressure, <120 mm Hg and diastolic blood pressure, <80 mm Hg). Urine albumin excretion and other biochemical analyses were performed using standard methods.

We recruited a total of 3300 subjects, the prehypertension group included 1100 individuals and the normotension group was composed of 2200 persons. The prevalence of microalbuminuria in subjects in the prehypertension group was 6.8% and in those who are the in the optimal BP group was 3.6% (P<0.001). Subjects in the prehypertension group had a mean B-type natriuretic peptide (BNP) level of 98 (72) pg/mL compared with 43.6 (20) pg/mL found among subjects in the normotension group (<0.001). In the logistic regression model, tobacco smoking aOR 2.7 (95% CI.; 1.7-5.8), higher uric acid level aOR 2.2 (1.7-3.2), microalbuminuria 7.6 (4.9-14.7) and a higher BNP level aOR 2.5 (1.8-7.6) were significantly associated with the occurrence of prehypertension.

Microalbuminuria, BNP level and hyperuricemia were significantly associated with prehypertension.