Arterial blood pressure in adult Nigerian sickle cell anaemia patients.

Sickle cell disease (SCD) is predominantly a problem of black community in whom a higher prevalence of hypertension has been reported. Despite these observations, a lower mean arterial blood pressure is observed to be common in homozygous sickle cell anaemia (SCA) patients, especially from outside Africa. In view of the well known diversity in both clinical and haematological presentations of SCD, we have evaluated the effects of sickled haemoglobin on blood pressure distribution in Nigerians with SCA. Arterial blood pressure was measured using mercury sphygmomanometer and the mean arterial pressure calculated in 64 adult Nigerians with SCA and 60 normal individuals. The mean age of SCA group was 22.14 +/- 4.90 years with a range of 18-57 years and in the controls was 27.18 +/- 8.06 years with a range of 18-54 years. The mean values of MAP 72.69 +/- 7.30 mmHg in SCA was significantly lower than 87.25 +/- 9.98 mmHg in the controls p < 0.007. The cause of this observed lower blood pressure in SCA is still speculative. We postulate that the differences in weight between SCA patients and normal individuals may contribute to this phenomenon. However, it is possible that nitric oxide (NO) or endothelial relaxing factor (EDRF) may also contribute to this lower blood pressure and the decrease in peripheral resistance in SCA.