Haematocrit, hypertension and smoking in patients with transient ischaemic attacks and in age and sex matched controls.

The blood pressure, smoking habit and haemotocrit of 154 patients with transient ischaemic attacks and 191 age-and sex-matched neurological controls were studied. Regression analysis revealed that the haematocrit value was related to both systolic and diastolic blood pressure, and to smoking. Smoking elevated the haematocrit by 1.9 +/- 0.59 in males and by 2.18 +/- 0.68 in females. When these associations were allowed for there was still evidence of a higher haematocrit in patients with transient ischaemic attacks (plus 1.44 +/- 0.56 in males and 0.75 +/- 0.75 in females p less than 0.02). The role of an elevated haematocrit in the pathogenesis of cerebrovascular disease and its management are briefly discussed.