Blood Pressure and Associated Risk Factors for Hypertension in Children with Sickle Cell Anaemia Attending University of Nigeria Teaching Hospital, Enugu, South-East Nigeria.

Abstract

Introduction: Sickle Cell Anaemia (SCA) is the homozygous state of heamoglobin SS gene. It is highly prevalent in Sub-saharan Africa with Nigeria ranking highest for people living with the disease. Blood pressure recording in individuals with SCA has been known to be influenced by certain factors such as age, sex, body mass index and hemoglobin level.

Aim: The study seeks to examine the relationship of certain pre-selected factors -age, gender, body mass index, disease severity and microalbuminuria/proteinuria on the blood pressure of children with SCA and document the relationship (if any) between above factors and the blood pressure readings of Nigerian children with SCA.

Methodology: A cross-sectional hospital-based study that consecutively recruited 106 children with sickle cell anaemia (HbSS) aged 3-17 years in steady state as well as age and sex-matched controls with HbAA genotype. Sociodemographic, clinical and anthropometric parameters were obtained. Severity of the disease and renal complication were assessed using Adeleke scoring method and microalbuminuria/ proteinuria assay. Subjects in crisis or had crisis in the past 4 weeks or genotype HbSC were excluded. For controls (genotype AA), those on management for congenital heart disease (CHD), hypertension and renal pathology were excluded.

Results: Weight and body mass index (BMI) were significantly lower in subjects compared to controls (p = 0.010 & 0.029 respectively). In subjects, the most common clinical attributes at presentation was bone pain (31.1% subjects), previous hospital admission (74.5%) and known steady state PCV (33.9%). Most of the subjects (87.74%) had mild SCA disease severity. Only two subjects (1.8%) had elevated BP while one subject (0.9%) had hypertension.Microalbuminuria (28.2%) and proteinuria (13.2%) were seen in subjects. While one control had elevated BP, none had hypertension. There was an initial positive relationship between increasing age (p= 0.007), low BMI (p= 0.008), presence of microalbuminuria/ proteinuria (Renal injury) p= 0.03 and raised blood pressure,but none of these associations was found to be an independent predictor of hypertension.

Conclusion/ recommendation: Elevated diastolic blood pressure and diastolic hypertension in children with SCA were shown to have an initial positive association with increasing age, low BMI and renal injury. These should be guarded against by instituting screening program and measures to stall progression.