Arterial blood pressure in children with sickle cell anaemia and controls: a cross sectional study

Abstract

Background: Sickle cell anaemia (SCA) is a very common disorder among indigenous people of Borno and Yobe States in the North-eastern region of Nigeria. It is characterized by recurrent episodes of severe bone pain from occlusion of blood vessels by sickled red cells. Hypertension in children with sickle cell anaemia is rare and when present may be secondary to other disease process and more rarely may be essential hypertension. However, when hypertension occurs in SCA patients, it accelerates the progression of complications such as cerebrovascular accident and sickle cell nephropathy, hence the need to study the pattern of blood pressure in these patients. Early detection of hypertension can help in forestalling its progression and preventing its devastating complications such as cerebrovascular accident.

Objectives: To compare the arterial blood pressures of children with sickle cell anaemia in steady state with those of age and sex-matched healthy controls. Methods: The study design was cross-sectional comparative. Minimum sample size of 54 was determined using Taylor’s formula. Subjects were recruited systematically by enrolling every other patient as they present at the Paediatric Haematology clinic. The controls were apparently healthy age and sex-matched haemoglobin AA children. Anthropometric parameters and the blood pressure were measured and recorded appropriately. Blood pressure was classified using published normative data.

Results: A total of 54 children with sickle cell anaemia in steady state and 159 normal children as controls were enrolled. The ages of both the SCA and controls ranged from 3 to 14 years, with median age of 8 years. Of the 54 SCA children 28 (52%) were males while 26 (48%) were females. Mean packed cell volume of the SCA children was 22 ± 3.5. Although 8 (14.8%) of the SCA children were hypertensive, there was no significant difference in the mean systolic blood pressure (96mmHg) of children with sickle cell anaemia compared to controls (99mmHg) P = 0.078 while, the mean diastolic blood pressure (65mmHg) of the control was significantly higher than that of SCA cohort (59) P ≤ 0.0001.

Conclusion: Hypertension is not rare among children with sickle cell anaemia. This stresses the need regular BP recording during follow-up in order to prevent devastating events such as cerebro-vascular accident.