The Protective Role of Sickle Cell Anemia in the Pathogenesis of Hypertension in Hyperuricaemic Subjects: A Preliminary Study

Abstract

The relationship between hyperuricaemia and blood pressure (BP) has been noted for more than half- a century ago. The possible pathogenetic pathway including its ability to induce arteriolopathy has recently attracted intense research. Interestingly, sickle cell anaemia (SCA) patients with high prevalence of hyperuricaemia have relatively low BP. This study was thus designed to evaluate the relationship between hyperuricaemia and BP in SCA subjects.

SCA patients attending Adult Sickle Cell Clinic who are in stable state with no renal diseases or drugs that could elevate serum uric acid (SUA) were studied. BP measurements were taken in the clinic with a mercury sphygmomanometer at two different visits of 4 weeks interval .The average BP and the mean arterial pressure (MAP) were calculated. Blood samples were taken for SUA, serum creatinine and urea estimations.

Forty nine (49) patients (24 males. 25 females) were studied. Hyperuricaemia was present in (32.6%) of the 49 patients. Their mean ages were 30± 9.8 in the hyperuricaemic group and 25±9.5 in the normouricaemic group. The mean of the measured variables were: SUA = 0.51± 0.10 range =0.43 -0.62mmol/L and MAP=76.52 ± 7.70 range =63.33 - 89.33mmHg in the hyperuricaemic  group. The corresponding values for the normouricaemic group were: SUA =0.29±0.08 (range =0.05-0.40mmol/ L) and MAP = 82.93 ± 12.13 (range = 70.00 - 114.69) mmHg. The BP in the hyperuricaernic group was significantly lower than the normouricaemic group; t =2.24; (P<0.05).

Hyperuricaemia tends to occur in older SCA patients and seems to have an inverse relationship with BP. However the small population studied does not allow a very strong conclusion on the relationship between hyperuricaemia and BP among SCA patients. A longitudinal study with larger population of SCA patients with hyperuricaemia is recommended.