Prevalence and factors associated with microalbuminuria among children with sickle cell anaemia attending the sickle cell clinic in mulago hospital.

Abstract

BACKGROUND: Sickle cell anaemia is by far the commonest hereditary haemolytic disease in Uganda; it is a chronic disease with multi organ complications. Chronic renal failure is one of the most serious complications of sickle cell anaemia affecting up to 18% of all affected individuals. Survival after a diagnosis of renal failure is less than five years. Microalbuminuria due to glomerular basement membrane damage is one of the earliest preclinical markers of kidney dysfunction in patients with sickle cell anaemia. The prevalence of microalbuminuria was found to be as high as 26% among children aged <_ 18 years in one of the studies done in the USA. Screening for microalbuminuria in patients with sickle cell anaemia (SCA) helps detect early renal damage hence measures to alter progression to chronic renal failure can be institututed thus improving the clinical outcomes. METHODS: We carried out a cross sectional study to determine the prevalence and factors associated with microalbuminuria among children aged 2-18 years with sickle cell anaemia attending the sickle cell clinic in mulago hospital. Out of the 392 children screened, 305 children were recruited. For each enrolled child, a spot urine sample was analysed for albumin, creatinine and nitrine while a concurrent blood sample was analysed for the haemoglobin level and serum creatinine. Microalbuminuria was defined by the urine albumin: creatinine ratio ranging from 30 t0 300 micrograms of albumin per milligram of creatinine. RESULTS: The prevalence of microalbuminuria in the study population was 28.2%. 4/305 participants had macroalbuminuria. Increasing age, a lower haemoglobin level, multiple previous blood transfusions and the presence of nitrite in urine were found to be significantly associated with microalbuminuria. The mean age of children with microalbuminuria was 11.7 versus 8.9 years for those without (P value= 0.000) and the mean haemoglobin level of children with microalbuminuria was 7.06 versus 7.59g/dl for those without. (P value = 0.018). The youngest participant with microalbuminuria was 5 years old. One study participant had elevated creatinine level above 1 mg/dl. CONCLUSIONS: The prevalence of microalbuminuria was found to be higher than what was found in previous studies done among participants of the same age in the USA. Microalbuminuria was noted to be strongly and directly related to age and inversely related to haemoglobin levels. Screening for microalbuminuria seems a prudent clinical decision among children with sickle cell anaemia aged 5 years or more.