Hemorheology in complicated hypertension

During essential and secondary arterial hypertension it is possible to obse rve changes in microcirculation perfusion associated with a reduction in ti ssue oxygenation due in part to hemorheological changes such as an increase in blood viscosity or the formation of the red blood cell "rouleaux" which favour an increase in peripheral resistance and can cause or worsen arteri al hypertension. We studied 21 healthy subjects (11 male and 10 female aged 42 +/- 4) and 26 hypertensive subjects (14 male and 12 female aged 49 +/- 3). The patients were non smokers and non suffering from respiratory or haemathological path ologies. They were not undergoing antihypertensive or vasodilatory pharmace utical treatment. The patients suffered from mild hypertension (II WHO) wit h Peripheral Occlusive Arterial Disease (POAD II "a" acc. to Leriche-Fontai ne class.). The patients showed an increase in cholesterolaemia (6.42 +/- 0 .81 mmol/l) and trygliceridaemia (2.73 +/- 0.09 mmol/l) at an average level . The patients were studied in standard conditions with a constant temperat ure of 22 degrees C. We measured SBP, DBP, MBP, and the HR. We also measured the elongation index (EI) (with shear stress range 0.30 to 30 pascals) using LORCA, acc. to Hardeman method (1994), in order to study the erythrocyte deformability and aggregation kinetics in dynamic conditio n. To evaluate deformability in static conditions we calculated the Erythro cyte Morphologic Index (EMI), acc. to Forconi method, via the bowl/discocyt e ratio (for 100 red blood cells fixed in glutaraldehyde at 0.3% and observ ed with an optical microscope under immersion in glycerol). Peripheral oxyg enation was taken transcutaneously (TcpO(2)). To establish the level of vas cular disease we used the Regional Perfusion Index (RPI = TcpO(2) foot/TcpO (2) subclavean) and doppler guided Winsor Index (WI). The Student "t" test and linear regression were used for the statistical analysis. Our data confirm a reduction in peripheral tissue oxygenation in hypertensi ves especially if suffering from vascular disease which correlates signific antly (p < 0.01) with a reduction in red blood cell deformability. This itself can increase peripheral resistances and favour the onset of hem orheological complications, at a cerebral-vascular level, which are frequen t in hypertensives.