Age- and gender-specific reference values for urine albumin/creatinine ratio in children of southwest China

Background: The reference value for the urine albumin/creatinine ratio (ACR) varies between races and has not been previously validated in children. We assessed the ACR reference values and the factors that affect them in a population of healthy Chinese children. Methods: A total of 1986 healthy children (1078 males, 908 females) aged 6-19 y were enrolled. The 95th percentile of ACR was used as the normal upper limit. The associations between ACR and gender, age, body mass index (BMI), systolic blood pressure (SBP), preterm birth, intake of fruits, smoking, and geographical area were examined. Results: The normal upper limit of ACR was 14.7 mg/g for male children and 19.8 mg/g for female children. The ACR value for girls was significantly higher than that for boys (P < 0.001). ACR was inversely correlated with age (P < 0.001) and positively correlated with BMI, SBP, and smoking (all P < 0.01). Conclusions: The ACR reference value for healthy children in southwest China is approximately the same as the value for adults, but lower than that for the Western population. Age, SBP, BMI, and smoking in children influence ACR. (C) 2014 Elsevier B.V. All rights reserved.