Preferential changes in hepatosplanchnic hemodynamics in patients with borderline hypertension

To investigate changes in systemic and regional hemodynamics during the development of human hypertension, we simultaneously measured cardiac index (CI) by the indocyanine green (ICG) dye dilution method, hepatosplanchnic blood flow (HBF) by the ICG clearance method using a two-compartment model, and renal blood flow (RBF) by the p-aminohippurate clearance method in patients with borderline and essential hypertension. In patients with borderline hypertension (BH, n = 27), HBF (435 +/- 15 ml/min/m2) and HBF/CI (16 +/- 1%) were significantly (p < 0.05) lower than in age-matched normotensive controls (528 +/- 21 and 19 +/- 1, respectively, n = 21), while CI, RBF and RBF/CI were similar. In patients with essential hypertension (EH, n = 32), HBF, RBF, and RBF/CI were all significantly (p < 0.01) lower than in the control subjects. Hepatosplanchnic vascular resistance (HVR) in patients with BH was preferentially increased, while total peripheral resistance (TPR) and renal vascular resistance (RVR) remained in the normal range. In patients with EH, TPR, HVR, and RVR were all increased. These results indicate that hemodynamic changes in patients with BH do not occur uniformly among the various regional circulations and suggest that hemodynamic changes in the hepatosplanchnic region precede those in other organ circulations during the development of human hypertension.