Prevalence of Persistent Proteinuria using Urine Protein/Creatinine Ratio in Asymptomatic Primary School Children in Calabar, Nigeria

Abstract

Background: Quantitative urinary protein estimation is the cornerstone in the diagnosis, treatment and prognostication of renal diseases. This could either be carried out by 24-hour urine protein estimation or spot urine protein: creatinine (UPC) ratio. The latter is simple, convenient, quick and reliable. It can be used in the follow-up of asymptomatic proteinuric children at risk of developing chronic renal disease.
Aim: To determine the prevalence of persistent proteinuria in asymptomatic primary school children in Calabar, Nigeria using the UPC ratio.
Methodology: This was a descriptive cross-sectional study of 1,600 apparently healthy primary school children aged 5 to 12 years recruited by multi-stage sampling. Urinalysis using dipstick was performed and those with significant proteinuria (proteinuria ≥ 1+) had urinalysis repeated after two weeks. Those with persistent proteinuria were quantitated using the modified Biuret method while urine creatinine was measured with the modified Jaffe Kinetic method (done with the Biolabo creatinine kit). Urine protein:creatinine ratios > 0.20 were confirmed as persistent proteinuria.
Results: Out of the 1,600 pupil, 761(47.6%) were males and 839(52.4%) females, giving a male to female ratio of 1:1.1. The mean age was 8.7 ± 1.9 ranging from 5-12 years.
The modal age group was 9-10 years. The prevalence of persistent proteinuria using the dipstick urinalysis was 1.8% while with the UPC ratio was 1.6%. There was a high female preponderance 19 (1.2%) of persistent proteinuria, which was statistical significant. Age and social class did not contribute significantly to having persistent proteinuria.
Conclusion: The prevalence of persistent proteinuria in these asymptomatic children using UPC ratio was almost similar to the repeat urinalysis done after two weeks. It is hereby recommended that where UPC ratio is not available a positive repeat urinalysis using first void early morning urine after two weeks can be used as persistent proteinuria. This information will enable proper treatment and follow-up which will forestall rapid progression to kidney damage.

Keywords: Urinalysis,Protein: Creatinine Ratio,Asymptomatic Children.