Etiology, Comorbidities, and Rate of Progression of Pediatric Chronic Kidney Disease: A Cohort Study

Objectives To evaluate the etiology of pediatric chronic kidney disease (CKD), assess comorbidities, and identify rate of progression of CKD and its risk factors. Methods Children aged 2-18 y with the Kidney Disease Improving Global Outcome (KDIGO) CKD stages 2-4 were enrolled. The etiology of CKD and its comorbidities were recorded. Kaplan-Meier survival curves were used to analyze the time to progression of CKD. Results Of the 131 patients enrolled, CKD stages 2, 3a, 3b, and 4 constituted 62 (47.3%), 17 (13%), 26 (19.8%), and 26 (19.8%), respectively. At the last follow-up [at median (IQR) 24 (12, 30) mo], the number of children in CKD stages 2, 3a, 3b, 4 and 5 were 48 (36.6%), 16 (12.2%), 23 (17.6%), 28 (21.4%), and 16 (12.2%), respectively. Etiologies of CKD included obstructive uropathy [48 (36.6%)], chronic glomerular disease [19 (14.5%)], reflux nephropathy [14 (10.7%)] and cystic renal disease [11 (8.3%)]. Comorbidities during follow-up included CKD-MBD [87 (66.4%)], metabolic acidosis [95 (72.5%)], hypertension [88 (67.1%)], growth retardation [69 (52.6%)], and anemia [63 (48.1%)]. The number of patients with metabolic acidosis, hypertension, MBD and anemia in CKD stage 2 were 27 (56%), 26 (54.2%), 24 (50%), 15 (30%), respectively. The median (IQR) rate of decline in eGFR was 3.3 (2, 4.6) mL/min/1.73 m(2)/y. On multivariable analysis, proteinuria [hazard ratio 3.5 (95% CI 1.4, 8.8) p = 0.01] and hyperphosphatemia [hazard ratio 2.2 (95% CI 1.1, 4.3) p = 0.03] were significant predictors for progression of CKD. Conclusions Even the earlier stages of CKD had significant comorbidities. The median decline in eGFR was 3.3 mL/min/1.73 m(2)/y. Proteinuria and hyperphosphatemia were the risk factors for progression of CKD.