PROGRESSION TO HYPERTENSION AND DEVELOPMENT OF TARGET ORGAN DAMAGE IN SUBJECTS WITH HIGH NORMAL BLOOD PRESSURE IN A GENERAL POPULATION: THE VOBARNO STUDY: 1B.06

Abstract

Background: Subjects with high-normal (HN) blood pressure (BP) may be at increased risk of progression to hypertension (HT) and of cardiovascular events, in comparison with normotensives (NT). Aim of our study was to evaluate the progression to hypertension and the development of target organ damage in a general population in Northern Italy. Methods In 585 subjects (age 50 ± 8 years, 46% males) a baseline visit and laboratory examinations were performed. Subjects were divided into 3 groups according to systolic (SBP) and diastolic blood pressure (DBP) values: NT (SBP/DBP < 130/85 mmHg); HN (SBP/DBP >130/85 and < 140/90 mmHg) and HT (SBP/DBP > 140/90 mmHg). In 478 subjects a follow up (FU) visit, laboratory examinations, measurement of carotid femoral pulse wave velocity (PWV) and carotid intima media thickness (IMT) were performed after 8.7 ± 2.3 years. Results: At baseline 30% of patients were NT, 25% were HN and 45% were HT. Among patients classified as HN at baseline, 71% developed hypertension at FU, 18% had HN BP, 11% were NT. Among subjects classified as NT at baseline, 34% developed hypertension at FU, 23 % were classified as HN and 43 % were NT. Mean BP values at FU were 129 ± 13/82 ± 7 in NT, 139 ± 13/87 ± 6 in HN, 146 ± 15/89 ± 8 mmHg in HT, respectively (ANOVA p < 0.001). At FU in HN and in HT, as compared with NT, a significant increase of PWV (11.2 ± 2.1 and 12.4 ± 3.3 vs 10.1 ± 1.9 m/sec, ANOVA p < 0.01) and of common carotid IMT (1.00 ± 0.19 and 1.09 ± 0.27 vs 0.93 ± 0.15 mm, ANOVA p < 0.01) was observed. Conclusions: In a general population in Northern Italy a large proportion of subjects with high normal BP developed hypertension and vascular target organ damage during a 9 years follow up.