6311 Assessment of the blood pressure profile of children with sickle cell anaemia aged 3–17 years in sub-Saharan Africa: a comparative study

Objectives Sickle cell anaemia (SCA) is the commonest monogenic blood disorder prevalent in sub-Saharan Africa. Nigeria has the highest burden of the disease. One of the major features of SCA is the unusual blood pressure (BP) profile in subjects. However, there has inconsistency in their blood pressure profile. Previous studies on BP profile in children with SCA noted them to have relatively lower BP recordings in comparison to their controls.¹ ² Subsequently, some studies began to document high prevalence of HTN in children with SCA using ambulatory blood pressure monitoring (ABPM) with prevalence figures comparable and even sometimes higher than values obtained in the non-SCA normal population.³ This was attributed to masked hypertension has which results from the loss of the usual nocturnal dip in blood pressure which occurs in apparently healthy individuals. Studies on BP profile of Nigerian children have shown varying and conflicting results.⁴ ⁵ This research therefore seeks to re-examine the BP profile of children with SCA in Nigeria to determine its likely trend in comparison to current findings with ABPM. Methods This cross-sectional comparative study was undertaken at the University of Nigeria Teaching Hospital, Enugu over a period of 7 months (July 2020 – January 2021). It involved 212 participants aged 3–17 years (106 subjects with HbSS and 106 age/gender matched controls with haemoglobin genotype AA). A semi-structured questionnaire was used to obtain socio-demographic and clinical data. Blood pressure was measured using Accoson mercury sphygmomanometer on 3 separate occasions for each patient. Results Figure 1 shows the blood pressure profile of SCA subjects. There was a significant difference in the systolic blood pressure (SBP) of subjects compared to the controls (p = 0.01) as seen in table 1. The subjects had 4 times lower odds of having SBP <50th centile than the controls [OR, (95% CI), 0.43(0.22 – 0.84)]. Though not statistically significant, the mean SBP and mean DBP in the subjects were higher than the values in the controls (95.51±12.25 mmHg vs 94.25 ±11.23mmHg and 58.25 ±8.05 mmHg vs 56.56 ±8.03mmHg). Conclusion Although hypertension is still rare in children with sickle cell anaemia, there seems to be changing trend in their blood pressure profile tending towards elevated blood pressure and hypertension. They should therefore be monitored more closely, now more than ever, for the onset of hypertension and its morbid complications. References Serjeant G. Natural history of sickle cell disease. Cold Spring Harb Perspect Med. 2013;3:a011783. Rees DC, William TN, Gladwin MT. Sickle-cell disease. Lancet. 2010;376:2018–31. Moodalbail DG, Falkner B, Keith WS, Mathias RS, Araya EC, Zarinsky JJ, et al. Ambulatory blood pressure in a pediatric cohort of sickle cell disease. J Am Soc Hypertens. 2018;12:542–50. Ekure EN, et al. Systolic blood pressure of Nigerian children with sickle cell disease. Niger J Paediatr.2012;39:105–9. Ajite A, Ogundare E, et al. The pattern of blood pressure and renal function among children with sickle cell anaemia presenting in a tertiary health institution in Nigeria. J Clin Nephrol. 2019;3:83–92.