Reference intervals for serum bilirubin, urea, and uric acid in healthy Chinese geriatric population

OBJECTIVES: The study aims to establish the reference intervals (RIs) for total bilirubin (TBIL), direct bilirubin (DBIL), urea (UR), and uric acid (UA) in healthy Chinese geriatric population. METHODS: Eight hundred and twenty cases from six representative geographical regions in China (including male 413 cases and female 407 cases) of apparently healthy individuals aged 60-96 years were recruited. Serum TBIL, DBIL, UR, and UA were analyzed by automatic biochemical analyzer and RIs were determined following CLSI C28-A3 guidelines using a non-parametric method. RESULTS: In apparently healthy Chinese geriatric population of China, the RIs of TBIL, DBIL, UR, and UA were 6.6~21.8 μmol/L, 1.9~8.0 μmol/L, 3.60~9.51 mmol/L, 179.2~460.9 μmol/L in males and 6.1~20.0 μmol/L, 1.8~7.1 μmol/L,3.35~8.89 mmol/L, 130.2~443.4 μmol/L in females, respectively. CONCLUSIONS: The RIs of TBIL, DBIL, UR, and UA were established within apparently healthy geriatric Chinese population according to CLSIC28-A3 document, providing a reference for the clinical.