Different alterations of glomerular filtration rate and their association with uric acid in children and adolescents with type 1 diabetes or with overweight/obesity.

ABSTRACT

BACKGROUND: Hyperfiltration (HF) occurs early in diabetes or obesity (OB)-associated renal disease. Alterations of glomerular filtration rate (GFR) in childhood OB remain unclear. OBJECTIVES: To compare the prevalence of GFR alterations and its association with uric acid in children and adolescents with type 1 diabetes (T1D) vs overweight (OW)/OB. METHODS: Cross-sectional study of 29 youths (aged 13 ± 2 years) with T1D (disease duration 7 ± 3 years) and 165 with OW/OB (aged 11 ± 3 years). Patients with an albumin-creatinine ratio >3.39 mg/mmol were excluded. GFR was estimated with creatinine-cystatin C Zappitelli equation. HF and low GFR were defined by a GFR > 135 and <90 mL/min.1.73 m2 , respectively. RESULTS: HF was higher in children with T1D vs OW/OB (28% vs 10%, P < .005). Children with OW/OB also showed a 10% of low GFR. In patients with T1D, HbA1c (ß = .8, P < .001), and systolic blood pressure (ß = 11.4, P < .005) were independent predictors of GFR (R2 = .65). In OW/OB, HF cases were almost limited to prepubertal children and low GFR to pubertal ones. GFR in OW/OB was associated with age (ß = -2.2, P < .001), male sex (ß = -11.6, P < .001), and uric acid (ß = -.05, P < .001) in adjusted models (R2 = .33). CONCLUSIONS: GFR alterations were different between youths with T1D and with OW/OB. Higher uric acid, older age, and puberty were related to lower GFR values in OW/OB children. Longitudinal studies will determine if low GFR is consequence of a rapid GFR decline in pediatric patients with OW/OB.