Objective: To evaluate the prevalence renal dysfunction and to compare glomerular and tubular function between cyanotic and acyanotic CHD in children and adolescent. Correlations among clinical factors, urinary glomerular and tubular markers for kidney injury were also determined.

Material and Method: Renal function was determined by estimated glomerular filtration rate, urine protein/creatinine, urine microalbumin/creatinine, FE Na+, FE Mg2, and urine NAG/creatinine in children and adolescent with CHD.

Results: Forty-six patients, 15 cyanotic (group 1), and 31 acyanotic CHD (group 2), were studied. Only the differences of urine NAG/creatinine (median, 3.59 vs. 1.64 unit/gram creatinine; p = 0.008), FE Mg2+(mean, 5.03 ± 3.61% vs. 2.48 ± 1.8%; p = 0.019), and urine protein/creatinine between the two groups were statistically significant (0.16 vs. 0.08; p = 0.001). No significant differences of clinical features, BUN, creatinine, eGFR, diastolic blood pressure, FE Na+ , and urine microalbumin/creatinine were found between the two groups. Significantly higher prevalence of abnormal biochemical markers in group 1 compared to those of group 2: 86.6% vs. 43.38% (p = 0.02) for FE Mg2+; 46.6% vs. 9.67% (p = 0.008) for urine NAG/creatinine; 46.6% vs. 6.45% for significant proteinuria (p = 0.003); and 40% and 9.67% (p = 0.042) for microalbuminuria, respectively. The authors found moderate correlation between hemoglobin and functional class of the patients (r = 0.58) and highly negative correlation between oxygen saturation and functional class (r = -0.716). The relationships among other clinical or biochemical makers showed only low correlations.

Conclusion: Cyanotic CHD patients had more prevalence and higher abnormal biochemical markers for renal dysfunction than those of acyanotic CHD. Their urine protein/creatinine, FE Mg2 and urine NAG/creatinine were higher than those of acyanotic CHD. Only low correlation among biochemical markers was found.

Keywords: Renal dysfunction, Glomerular dysfunction, Tubular dysfunction, Cyanotic congenital heart disease, Acyanotic congenital heart disease