Reference Intervals And Reference Change Values Of Serum Creatinine, Alanine Aminotransferase And Pepsinogen Levels In The Healthy Geriatric Population

Part Ⅰ. The differences of biological parameters between the healthy adult population and the healthy geriatric populationObjectiveTo investigate the differences of biological characteristics and parameters between the healthy adult population and the healthy geriatric population, and provide a basis theoretical for the establishment in the healthy geriatric population reference intervals for routine clinical laboratory tests.MethodsDetermination BMD, SBP, DBP, ALB, Hb, ALT, ALP levels for948healthy adults (487males,461females,aged from18to59years) and743healthy elders (369male,374female,aged from60to89years old), and comparing differences of these biological characteristics in two populations.ResultsThere is a significant difference of BMD, SBP, DBP, ALB, Hb, ALT, ALP levels in different gender and age group (60to69,70to79,80to89years in three age groups) between h between the healthy adult population and the healthy geriatric population, p<0.05.ConclusionsThere are significant differences of biological characteristics and parameters between the healthy adult population and the healthy geriatric population, which suggested that the clinical laboratories should establish different reference intervals for the geriatric population. Part Ⅱ. The reference intervals for Scr, ALT and PG Ⅰ, PGⅡ and PGⅠ/Ⅱ of the healthy geriatric populationObjectiveTo establish the reference intervals for Scr, ALT, PG Ⅰ, PGⅡ and PG Ⅰ/Ⅱ in the healthy geriatric population.MethodsAccording to CLSI document C28-A3of reference individual and reference population screened standards, healthy, elderly Chinese Han ethnic individuals aged between60and89years old were recruited for this study. We stratified the reference individuals by gender and age (60-69,70-79and80-89years), and the Scr, ALT, PG I and PG level II values were measured. The central95percentile RIs were determined using non-parametric statistical methods.ResultsThe Scr values in the elderly population show a Gaussian distribution and age/sex related differences. The RIs for Scr in the reference population with respect to age (ranges of60-69,70-79and80-89years) were53.4-95.6,58.2-05.6,60.0-111.3μmol/L for males, respectively, and3.8-76.2,46.7-87.2,48.1-92.2μmol/L or females, respectively. The ALT values in the elderly population show a non-Gaussian distribution and age/sex related differences. The RIs for ALT in the reference population with respect to age (ranges of60-79and80-89years) were7.5-26.8IU/L,7.2-17.2IU/L for males, respectively; and6.0-18.8IU/L (ranges of60-89years) for females. The PG I values in the elderly population show a non-Gaussian distribution and age/sex related differences. The RIs for PG Ⅰ in the reference population with respect to age (ranges of50-79,80-89years) were29.72-196.31ng/mL,33.01-220.69ng/mL for males, respectively; and25.78-150.09ng/mL,34.55-167.42ng/mL (ranges of40-79,80-89years) for females, respectively. The PG II values in the elderly population show a non-Gaussian distribution and age/sex related differences. The RIs for PG II in the reference population with respect to age (ranges of50-79,80-89years) were7.14-30.56ng/mL,7.62-39.13ng/mL for males, respectively; and5.46-38.21ng/mL,6.14-46.72ng/mL (ranges of40-79,80-89years) for females, respectively. The RIs for PG Ⅰ/Ⅱ in the reference population with respect to age (ranges of60-89years) was2.06-6.56.ConclusionsWe have established the RIs of Scr, ALT and PG Ⅰ, PGⅡ and PG Ⅰ/Ⅱ in the healthy Chinese Han ethnic elderly population, which can provide a reference for both clinical and laboratory studies. Part III. The application of Scr based eGFR formulas to assessment GFR and the clinical application of the newly created ALT ULN in the geriatric populationObjectiveTo evaluate the applicability of Scr based eGFR formulas to assessment GFR and the clinical diagnosis performance of the newly created ALT ULN in the HBV and NAFLD geriatric population.MethodsThe five formulas including MDRD, Japan-MDRD, CKD-EPI, EPI-Asia, ca eGFR (the Chinese formula) were used to calculate the GFR for the geriatric population with different age groups; and we were taking advantage of the ROC curve to calculate diagnostic performance of the newly created ALT ULN in HBV and NAFLD the geriatric population.ResultsThe values of eGFR calculated by MDRD, Japan-MDRD, CKD-EPI, EPI-Asia, ca eGFR formulas, were more than50%of eGFR values less than90ml/min/1.73m2; and the diagnostic sensitivity of the newly created ALT ULN in HBV geriatric population, with respect to age (ranges of60-79,80-89years) were42.81%,47.22%for male, respectively, and40.35%(ranges of60-89years) for females. The sensitivity of the newly created ALT ULN in NAFLD geriatric population, with respect to age (ranges of60-79,80-89years) were66.09%,72.34%for male, respectively, and55.01%(ranges of60-89years) for females. The diagnostic sensitivities were significantly higher than the use of WS/T ULN in HBV and NAFLD geriatric population, but the specificity decreased slightly.ConclusionsMDRD, Japan-MDRD, CKD-EPI, EPI-Asia, ca eGFR equations are not suitable for evaluation of all healthy elderly population eGFR; and the diagnostic sensitivities by the newly created ALT ULN in HBV and NAFLD elderly patients were better than WS/T ULN. Part Ⅳ. The preliminary studies for clinical application of RCVs for Scr and ALT in the geriatric populationObjectiveTo explore the clinical applicability of RCVs for Scr and ALT in the geriatric population.MethodsThe serum samples collected continuously four times for one month intervals, and the Scr and ALT values were measured. The RCVs and Ⅱ of Scr, and ALT were calculated according to Fraser RCVs formula.ResultsThe RCVs for Scr in the reference population with respect to age (ranges of60-69,70-79and80-89years) were20.25,18.43,17.40for males, respectively, and18.94,18.68,18.17for females respectively; Ⅱ were0.41,0.46,0.39for males, respectively,0.45,0.45,0.44for females, respectively. The RCVs for ALT in the reference population with respect to age (ranges of60-69,70-79and80-89years) were50.22,52.59,52.06for males, respectively, and69.98,71.06,71.60for females respectively; Ⅱ were0.34,0.34,0.38for males, respectively,0.47,0.57,0.51for females, respectively.ConclusionsThe Scr and ALT values for healthy geriatric population have obvious characteristics of individual index, which suggested that the Scr and ALT of RCVs were better than the RIs for diagnosis in clinical practice.