Ambulatory blood pressure monitoring in prehypertensive subjects

Although treatment of prehypertensives is feasible and effective, it is unclear how to define those who may benefit. We hypothesized that ambulatory blood pressure monitoring (ABPM) might be a tool for selecting prehypertensive subjects, classified according to the JNC 7, who later develop drug-treated hypertension.

Prehypertensives (n=107; 62 M, 45 F; age 50 ± 14 years) with or without cardiovascular risk factors were assessed for drug-treated hypertension development. They underwent ABPM at entry examination and were clinically followed-up for an average of 99 ± 42 months. Thereafter, subjects were divided into 2 groups according to the development of drug-treated hypertension. Stepwise logistic regression (LR) analysis was performed to assess the role of factors contributing independent prediction of outcome (i.e. drug-treated hypertension onset).

In LR analysis body mass index [odds ratio (OR)=1.29, confidence intervals (CI)95% 1.03-1.62], female gender (OR=11.10, CI95% 2.66-46.30), total cholesterol (OR=1.03, CI95% 1.01-1.05), smoking (OR=3.90, CI95% 0.94-16.20), daytime SBP (OR=1.10, CI95% 1.01-1.19) and 24h DBP (OR=1.23, CI95% 1.08-1.41) predicted the development of hypertension. The criteria combining BP and clinical variables were superior to BP or clinical criteria alone in the correct classification of true positives and true negatives. Altogether there was an improvement of 14.02% (p < 0.01) in comparison to only clinical criteria.

In the setting of global cardiovascular risk assessment, ABPM, in the early diagnosis of hypertension in prehypertensive individuals, appears as a useful tool, both diagnostically and prognostically, to index subjects who are suspected to be masked hypertensives.