Bjornstad Petter, Roncal Carlos, Milagres Tamara, Pyle Laura, Lanaspa Miguel Angel, Bishop Franziska K, Snell-Bergeon Janet K, Johnson Richard J, Wadwa R Paul, Maahs David M
Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA.
Barbara Davis Center for Diabetes, University of Colorado School of Medicine, Aurora, CO, USA.
Pediatr Nephrol. 2016 May;31(5):787-93. doi: 10.1007/s00467-015-3299-8. Epub 2015 Dec 23.
Urine uric acid (UUA) has been implicated in the pathogenesis of diabetic nephropathy via its effect on tubular cells. We hypothesized that the UUA level would be higher in adolescents with type 1 diabetes (T1D) than in those without T1D. We also hypothesized that UUA and fractional uric acid excretion (FeUA) would be higher in adolescents with T1D and hyperfiltration [estimated glomerular filtration rate (eGFR) ≥141 mL/min/1.73 m(2)] than in those without hyperfiltration.
The UUA concentration was determined and FeUA calculated in adolescents with (n = 239) and without T1D (n = 75). The eGFR was calculated using the Zappitelli equation based on serum creatinine and cystatin C concentrations.
Compared to the non-diabetic adolescents enrolled in the study, those with T1D had a higher eGFR (mean ± standard deviation: 120 ± 22 vs. 112 ± 16 mL/min/1.73 m(2); p = 0.0006), lower urine pH (6.2 ± 0.8 vs. 6.5 ± 1.0; p = 0.01), and higher UUA (37.7 ± 18.6 vs. 32.8 ± 18.1 mg/dL; p = 0.049) and FeUA (median [interquartile range]: 6.2 [4.3-8.7] vs. 5.2 [3.6-7.0] %; p = 0.02). Among adolescents with T1D, those with hyperfiltration had higher median FeUA (8.6 [5.2-9.9] vs. 6.0 [4.2-8.3] %; p = 0.02) than those without hyperfiltration.
The adolescents with T1D enrolled in the study had higher eGFR, higher UUA and more acidic urine than the non-diabetic controls, which may have increased their risk of UUA crystallization. Adolescents with T1D and hyperfiltration had higher FeUA than those without hyperfiltration. These hypothesis-generating observations may suggest a potential pathophysiologic association between uricosuria and hyperfiltration.
尿尿酸（UUA）通过对肾小管细胞的作用参与糖尿病肾病的发病机制。我们假设1型糖尿病（T1D）青少年的UUA水平高于非T1D青少年。我们还假设，T1D且伴有高滤过[估计肾小球滤过率（eGFR）≥141 mL/min/1.73m²]的青少年的UUA和尿酸排泄分数（FeUA）高于无高滤过的青少年。
测定了239例T1D青少年和75例非T1D青少年的UUA浓度并计算了FeUA。基于血清肌酐和胱抑素C浓度，使用扎皮泰利方程计算eGFR。
与本研究纳入的非糖尿病青少年相比，T1D青少年的eGFR更高（平均值±标准差：120±22 vs. 112±16 mL/min/1.73m²；p = 0.0006），尿pH值更低（6.2±0.8 vs. 6.5±1.0；p = 0.01），UUA更高（37.7±18.6 vs. 32.8±18.1 mg/dL；p = 0.049），FeUA更高（中位数[四分位间距]：6.2[4.3 - 8.7] vs. 5.2[3.6 - 7.0]%；p = 0.02）。在T1D青少年中，伴有高滤过的青少年的FeUA中位数（8.6[5.2 - 9.9] vs. 6.0[4.2 - 8.3]%；p = 0.02）高于无高滤过的青少年。
本研究纳入的T1D青少年的eGFR更高、UUA更高且尿液酸性更强，这可能增加了他们UUA结晶的风险。T1D且伴有高滤过的青少年的FeUA高于无高滤过的青少年。这些产生假设的观察结果可能提示尿酸尿与高滤过之间存在潜在的病理生理关联。
