Glomerular hyperfiltration in Yemeni children with sickle cell disease

Abstract

Background: Glomerular hyperfiltration (GH) is a common feature of sickle cell nephropathy (SCN) starting at infancy and represents an early marker of incipient glomerular injury and renal dysfunction. Methods: This study aimed to determine the prevalence and correlates of GH among children (≤ 16 years) with sickle cell disease (SCD) at their steady state, recruited over 6 months at the Pediatric Outpatient Clinic in Al-Sadaqa General Teaching Hospital, Aden, Yemen. Glomerular filtration rate (eGFR) was estimated using the Schwartz formula. Data on clinical history, anthropometry, blood pressure (BP) and laboratory investigations were collected. Results: Of 101 children (mean age 7.2 ± 3.9 years), 65 (64.4%) were males. The prevalence of GH was observed in 36 (35.6%) children, who were significantly older (10.7 ± 3.2 vs. 5.2 ± 2.7 years, p < 0.001) and had a lower fetal Hb level (5 ± 3.3 vs. 9 ± 7.1, p = 0.02). All children were normotensive, but hyperfiltrating children showed significantly higher systolic (97.2 ± 7.3 vs. 89.7 ± 5.2 mmHg) and diastolic pressure (55.1 ± 5.0 vs. 49 ± 4.3 mmHg) (all p < 0.001). Among evaluated children, 25.7% had hyperfiltration alone, whereas 9.9% had an associated microalbuminuria (MA), and no significant difference in eGFR between those with and without MA (158.4 ± 33.7 vs. 160.7 ± 29.8 ml/min/173m2, p = 0.84). Conclusion: This study demonstrated a relatively high prevalence of GH in Yemeni children with SCD that increased with age. Recognition of hyperfiltration and other early markers of nephropathy in this population could help to develop renal protective strategies to prevent progressive loss of kidney function.