Increased hematocrit before blood pressure in men who develop hypertension over 20 years.

We have previously demonstrated that neurohormonal activity can predict left ventricular (LV) mass in men who developed hypertension over 20 years. The aim of the study was to investigate early markers of cardiac and hemorheological changes at baseline in these men, i.e., before a rise in blood pressure. Fifty-six middle-aged men were followed for 20 years; 22 were sustained hypertensives, 17 developed hypertension, and 17 were sustained normotensives. They were compared at baseline (42 years) and follow-up (62 years). We investigated Cornell voltage product and Sokolow-Lyon voltage, hematocrit (Hct), and echocardiographic LV parameters. There was no sign of LV hypertrophy by electrocardiography (ECG) at baseline. Baseline Hct discriminated between the groups (P= .015) and correlated to diastolic blood pressure (DBP) at baseline (r = 0.37, P= .006) and follow-up (r = 0.31, P= .020). Regression analysis identified baseline Hct as an independent correlate of DBP in the cohort at baseline when they were untreated (beta = .33, P= .013, R(2) = 0.25), and of borderline significance at follow-up (beta = .26, P= .060, R(2) = 0.12) despite possible interference by antihypertensive drugs. Hct was elevated at baseline compatible with the hypothesis that pathogenic hemorheological processes could be activated at the outset and prior to cardiac changes in men who later develop hypertension.