Hemorheology and hypertension: not "chicken or egg" but two chickens from similar eggs.

A number of clinical studies have demonstrated significant positive correlation between the severity of arterial hypertension (AHT) and whole blood viscosity. Red blood cell aggregation has also been associated with AHT especially in the severe form of the disease. The main possible cause of increased red blood cell aggregation is fibrinogen which can be found in a significantly higher concentration in patients with AHT than in healthy controls. On the other hand, blood pressure reduction with angiotensin-converting-enzyme inhibitors, calcium-channel-blocking agents, beta or alpha-receptor blocking drugs leads to a significant improvement of blood rheology. It can be presumed that abnormal hemorheology and AHT are not directly linked but they share the same inductive genetic and/or environmental factors like obesity, chronic mental stress, physical inactivity and cigarette smoking. Regarding this hypothesis, the appropriate question is not whether hemorheological factors are causes or results of AHT but what their common origins are. Further studies are needed to clarify this hypothetical link between hemorheology and AHT.