Birth weight and renal markers in children aged 5-10 years in Cameroon: a cross-sectional study

Background A relationship exists between birth weight (BW) and glomerular filtration rate (GFR) in postnatal kidney. Willing to fill a gap of knowledge in sub-Saharan Africa, we assessed the effect of BW on blood pressure (BP), proteinuria and GFR among Cameroonians children. Methods This was a cross-sectional hospital-based study from January to April 2018 at the Yaounde Gynaeco-Obstetric and Paediatric Hospital (YGOPH). We recruited low BW (LBW) [< 2500 g], normal BW (NBW) [2500-3999 g] and high BW (HBW) [> 4000 g] children, aged 5-10 years, born and followed-up at YGOPH. We collected socio-demographic, clinical (weight, height, BP), laboratory (proteinuria, creatinine), maternal and birth data. The estimated GFR was calculated using the Schwartz equation. Results We included 80 children (61.2% boys) with 21 (26.2%) LBW, 45 (56.2%) NBW and 14 (15.5%) HBW; the median (interquartile range) age was 7.3 (6.3-8.1) years and 17 (21.2%) were overweight/obese. Two (2.5%) children, all with a NBW (4.4%), had an elevated BP whereas 2 (2.5%) other children, all with a LBW (9.5%), had hypertension (p = 0.233). Seven (8.7%) children had proteinuria with 19, 2.2 and 14.3% having LBW, NBW and HBW, respectively (p = 0.051). Equivalent figures were 18 (22.5%), 14.3, 24.2 and 28.6% for decreased GFR, respectively (p = 0.818). There was a trend towards an inverse relationship between BW and BP, proteinuria and GFR (p > 0.05). Conclusion Proteinuria is more pronounced in childhood with a history of LBW and HBW while LBW children are more prone to develop hypertension. Regular follow-up is needed to implement early nephroprotective measures among children with abnormal BW.