Establishment of the reference intervals of four biochemical parameters for liver function among adults in Changchun, China based on the indirect method

ObjectiveTo establish the reference intervals (RIs) of the four biochemical parameters for liver function ［aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), and alkaline phosphatase (ALP)］ in adults by using the indirect method based on the data of subjects undergoing physical examination in laboratory information system (LIS). MethodsWith the help of the LIS, related data were collected from the healthy adults who underwent physical examination in Physical Examination Center of The First Hospital of Jilin University from October 2019 to October 2020. The Kolmogorov-Smirnov test was used to check the normal distribution of the original data; data with skewed distribution were transformed into data with approximate normal distribution using the BOX-COX method; the Turkey method was used to remove outliers; the Mann-Whitney U test or the Z-test was used for comparison between groups; the non-parametric method was used to calculate RIs. ResultsA total of 27 218 subjects were included after the removal of outliers. All four parameters showed age and sex differences. The RIs of AST were 14-39 U/L for male individuals aged 20-79 years, 12-32 U/L for female individuals aged 20-49 years, and 14-39 U/L for female individuals aged 50-79 years; the RIs of ALT were 10-71 U/L for male individuals aged 20-54 years, 10-49 U/L for male individuals aged 55-79 years, 7-43 U/L for female individuals aged 20-49 years, and 9-49 U/L for female individuals aged 50-79 years; the RIs of GGT were 11-70 U/L for male individuals aged 20-64 years, 10-64 U/L for male individuals aged 65-79 years, 6-45 U/L for female individuals aged 20-49 years, and 7-54 U/L for female individuals aged 50-79 years; the RIs of ALP were 38-96 U/L for male individuals aged 20-79 years, 33-89 U/L for female individuals aged 20-49 years, and 40-106 U/L for female individuals aged 50-79 years. The RIs of AST, ALT, and GGT established in this study were similar to those in the industry standards of China (relative deviation ＜ reference change value), and the RIs of all four biochemical parameters were verified by applicability. ConclusionThe RIs of the four biochemical parameters for liver function established by the indirect method are relatively consistent with those established by the direct method, which holds promise for application in clinical laboratory