Purpose: Although microalbuminuria is known as a predictor of clinical nephropathy and cardiomyopathy, few studies have investigated the incidence and reference range of microalbuminuria in healthy children. This study aimed to establish a reference range and to study the age-related trend for spot urine microalbumin/creatinine ratio in a Korean pediatric population.
Materials and methods: 352 healthy children were studied from July 2007 through March 2010. Height, weight, serum creatinine, spot urine microalbumin/creatinine ratio, and glomerular filtration rate (GFR) were obtained for each subject. We divided the study population into 5 groups according to age, and compared the spot urine microalbumin/creatinine ratio with other variables using one-way analysis of variance (ANOVA), regression analysis and Pearson's correlation analysis.
Results: In this study, the data showed that the spot urine microalbumin/creatinine ratio decreased with age: 1-12 months, 22.72 ± 13.80 mg/mmol (2SD: 3.33-54.40 mg/mmol); 13-28 months, 16.34 ± 9.58 mg/mmol (2SD: 3.16-35.19 mg/mmol); 29-48 months, 13.12 ± 9.74 mg/mmol (2SD: 3.01-41.57 mg/mmol); 4-6 years, 10.58 ± 8.13 mg/mmol (2SD: 0.00-30.19 mg/mmol); and 7-19 years, 5.13±5.44 mg/mmol (2SD: 0.45-14.45 mg/mmol). The spot urine microalbumin/creatinine ratio showed correlation with age, height, height z-score, weight, weight z-score, GFR, body mass index (BMI) and body surface area (BSA).
Conclusion: The spot urine microalbumin/creatinine ratio in normal Korean children decreased with age. This ratio could potentially be used to establish reference ranges and cutoff values for Korean children and to predict nephropathy and cardiomyopathy.