Estimated glomerular filtration rate in apparently healthy school children in Uyo, Nigeria, using the updated Schwartz Formula

Abstract

Background: Glomerular filtration rate (GFR) is the best indicator of renal function in children and adolescents. It is usually estimated in patients with renal diseases especially end stage renal disease without consideration of the possibility of its derangement in the general population, who may be asymptomatic. We set out to estimate GFR in a population of school children using the validated updated Schwartz formula (2009) to determine those with levels below ≤ 60ml/min/1.73m2 and document the factors associated with it.

Subjects and Methods: It was a cross-sectional study in children and adolescents drawn from a primary and a secondary school in a semi-urban community of Uyo local government area (LGA) of Akwa-Ibom

State, Nigeria, over a three-month period (June 2017 to August 2017).Anthropometric, social and laboratory parameters were determined using standard methods while GFR was estimated using the updated Schwartz formula.

Results: Two hundred children aged between four to seventeen years with a male to female ratio of 1:1.8 constituted the study population. The mean and median eGFR were 82.8±17.7ml/min/1.73m2and 81.0 ml/min/1.73m2 respectively. The percentage of children and adolescents with eGFR ≤ 60ml/min/1.73m2was 10.0%. Female gender and a large waist circumference were the factors that were significantly associated with reduced eGFR.

Conclusion: The percentage of apparently healthy school children and adolescents with eGFR< 60 ml/min/1.73m2 in our locale is high. We recommend a regular community based screening of children for CKD using this simple method.

Keywords: eGFR, children, Schwartz, female gender, waist circumference, Nigeria