Prevalence and Significance of Sickle Cell Trait in Nigerian Patients with Essential Hypertension

Dr Sagir G. Ahmed, Department of Haematology Aminu Kano Teaching Hospital PMB 3452, Kano Kano State, Nigeria. +2348034418015 drsagirahmed@yahoo.com Abstract lifestyle and nutritional culture of the Africans are Global epidemiology shows that hypertension becoming increasingly westernized over time and is severer, commoner and occurs at relatively younger might be partly responsible for rising incidence of nonage in the black Africans in comparison to the whites. communicable diseases, including hypertension, in Since sickle cell trait (SCT) was associated with Africa. This is consistent with the finding of higher hyperviscosity, we hypothesize that SCT is a possible prevalence of hypertension in urban populations in 1 risk factor for hypertension in blacks and it might be Nigeria . Moreover, the prevalence of adult partly responsible for the high prevalence and severity hypertension appears to be rising as previous studies of hypertension in blacks. Hence, we studied reported prevalence rates of about 12% in 1992, 20% in 1, 2, 3 haematological parameters and prevalence of SCT in 1999 and up to 36% in a more recent study in 2008 . hypertensive patients and evaluated the impact of SCT Global epidemiology had shown that hypertension is on response to anti-hypertensive therapy as seen in severer, commoner and occurs at relatively younger 4, 5, Aminu Kano Teaching Hospital, Nigeria. age in the black Africans than in the white Europeans 6 The hypertensive patients had WBC and . 9 9 platelet counts of 5.8 x10 /L and 225 x10 /L that did not Individuals with sickle cell trait (SCT) have significantly differ from the corresponding values of red cells with Hb AS genotype that contain about 40% 9 9 7 6.2 x10 /L and 235 x10 /L seen among the HbS and 60% HbA . The abundance of HbA prevents 7 normotensive controls (p>0.05), but the hypertensive sickling under physiological conditions . The patients had a haematocrit of 0.37L/L that was frequency of SCT is up to 20-25% in West Africa significantly lower than the value of 0.44L/L seen including Nigeria, and the frequency has reached among the normotensive controls (p 0.05). Hypertensive patients with SCT had black Africans with normal Hb AA genotype . mean systolic and diastolic pressures of 158 and 95 Haemorheological studies had revealed that systemic mm Hg that were significantly higher than the arterial blood pressure is generally influenced by corresponding values of 145 and 86 mm Hg seen in vascular peripheral resistance, which is in turn affected 12, 13 patients with Hb AA genotype (p<0.05). These by blood viscosity . We therefore hypothesize that results suggest that SCT was not a risk factor for SCT genotype is a possible risk factor for essential hypertension but it was associated with poor hypertension in blacks and it might be partly response to anti-hypertensive therapy in affected responsible for the high prevalence and severity of patients. Hence hypertensive patients with SCT hypertension in the black race. If our hypothesis is need closer monitoring during therapy. correct, we predicted that: 1 The prevalence of SCT among black patients