Establishing reference intervals for ALT, AST, UR, Cr, and UA in apparently healthy Chinese adolescents

Background: The current child-specific reference intervals (RIs) are inadequate or even unavailable for many analyses in China. Many of the RIs used in Chinese laboratories were derived from Chinese adult standards or from foreign studies. The aim of this study was to establish specific RIs for alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea (UR), creatinine (Cr) and uric acid (UA) for apparently healthy Chinese adolescents. Methods: Overall, 1682 apparently healthy adolescents were enrolled. Serum ALT, AST, UR, Cr and UA were measured by an ARCHITECT C-8000 automated chemistry analyzer. The 2.5th and 97.5th percentile RIs were determined using non-parametric methods. Results: The established reference intervals for ALT, AST, UR, CR and UA were 7.5-42.8 U/L, 12.8-40.2 U/L, 3.12-6.38 mmol/L, 42.7-91.2 mu mol/L, and 180.2-409.6 mu mol/L in boys and 6.5-32.8 U/L, 10.4-32.5 U/L, 3.05-6.47 mmol/L, 40.2-88.8 mu mol/L and 176.5-394.0 mu mol/L in girls, respectively. The median and upper and lower limits for the RIs of ALT, AST, Cr and UA were higher in boys than they were in girls (P < 0.05). Conclusion: RIs based on adult criteria are not applicable to adolescents. It was necessary to establish specific, accurate and suitable RIs for Chinese adolescents. We have established reference intervals of ALT, AST, UR, Cr and UA that are defined specifically for Chinese adolescents and are appropriate for universal use among Chinese laboratories.