Guo-Ming Zhang

Reference intervals for total bilirubin, ALT, AST and creatinine in healthy Chinese elderly.

Background The aim of this study was to establish the reference intervals (RIs) of total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate transaminase (AST), and creatinine (CREA) for apparently healthy elderly (Han ethnicity) in Shuyang, China. Material/Methods A total of 54 912 blood specimens from elderly residents age 65–104 years were collected by standard procedures in Shuyang county of Jiangsu province. TBIL, ALT, AST, and CREA for each participant were determined by automatic biochemical analyzer. Distribution and differences of TBIL, ALT, AST, and CREA were analyzed and compared between the elderly of the same age of different sexes and different ages of the same sex. RIs of TBIL, ALT, AST, and CREA were compared with the current RIs. The RIs and 95% confidence intervals were calculated using nonparametric method (2.5th–97.5th percentiles) according to the guideline of the Clinical and Laboratory Standards Institute. Results RIs established for the healthy elderly include: TBIL 7.8~30.6 μmol/L for males and 7.3~26.1 μmol/L for females; ALT 8.7~47.3 U/L for males and 8.4~45.2 U/L for females; AST 15.7~46.9 U/L for males and 15.1~46.2 U/L for females; and CREA 45.1~100.9 μmol/L for males and 38.7~85.0 μmol/L for females. Reference intervals of TBIL, ALT, AST, and CREA for male elderly were higher than those of females, and values of CREA increased with increasing age. Conclusions We have established a panel of locally relevant RIs. It is necessary to establish scientific and reasonable RIs of TBIL, ALT, AST, and CREA for the healthy elderly in our region, which will provide a reference for clinicians and inspection officers.

Reference Intervals of Alpha-Fetoprotein and Carcinoembryonic Antigen in the Apparently Healthy Population

Background The aim of this study was to calculate 95% reference intervals and double-sided limits of serum alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) according to the CLSI EP28-A3 guideline. Material/Methods Serum AFP and CEA values were measured in samples from 26 000 healthy subjects in the Shuyang area receiving general health checkups. The 95% reference intervals and upper limits were calculated by using MedCalc. Results We provided continuous reference intervals from 20 years old to 90 years old for AFP and CEA. The reference intervals were: AFP, 1.31–7.89 ng/ml (males) and 1.01–7.10 ng/ml (females); CEA, 0.51–4.86 ng/ml (males) and 0.35–3.45ng/ml (females). AFP and CEA were significantly positively correlated with age in both males (r=0.196 and r=0.198) and females (r=0.121 and r=0.197). Conclusions Different races or populations and different detection systems may result in different reference intervals for AFP and CEA. Continuous reference intervals of age changes are more accurate than age groups.

Reference intervals of carbohydrate antigen 19-9 in the apparently healthy adult population

To establish reference intervals of carbohydrate antigen 19‐9(CA 19‐9) according to the CLSI CA28‐A3 guideline and to evaluate age‐ and gender‐related variations.

A novel method for estimating LDC levels: total cholesterol and non-HDLC can be used to predict the normal LDLC level in apparently healthy population

Background Triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), and low-density lipoprotein cholesterol (LDLC) are usually ordered together to test lipid metabolism in physical examination and clinical application. LDLC is a component of TC and its change is closely correlated to TC. Objective We aim to predict the normal LDLC level by using TG, TC, HDLC and non-HDLC (nonHDLC) in this study. Methods TG, TC, HDLC, and LDLC data were obtained from Laboratory Information System (LIS) based on 4 years (Octo, 1, 2013-Sept, 30, 2017) period health check-up TG, TC, HDLC, and LDLC(direct clearance method) were measured using TBA2000FR biochemical analyzer. The nonHDLC was calculated with TC minus HDLC. Correlation between TG, TC, nonHDLC, and LDLC were analyzed using Spearman’s rank approach. Receiver operating characteristics curve analysis was used to evaluate the predictive of TG, TC and nonHDLC for the normal LDLC level(less than 130mg/dL). Results Both TC(r = 0.870) and nonHDLC (r = 0.893) were significantly positively correlated with LDLC. Area under curve of TC and nonHDLC can be used to predict normal LDLC level. Optimal thresholds were 182.5 mg/dL(4.72 mmol/L) for TC and 135.3 mg/dL(3.50 mmol/L) for nonHDLC. Based on these optimal thresholds, less than 0.5% and 0.4% of tests with elevated LDLC might be missed, but the missing elevated LDLC is not too high(less than 147.3 mg/dL). Conclusion If the nonHDLC is less than 135.3mg/dL(3.50 mmol/L) and/or TC is less than 182.5mg/dL(4.72 mmol/L) for the apparently healthy populations the LDLC level will be less than 130mg/dL(3.36 mmol/L). Total cholesterol and non-HDLC can be used to predict the normal LDLC level in apparently healthy population is a novel method for estimating LDC level.

Limiting the testing of urea: Urea along with every plasma creatinine test?

We found that it is not necessary to simultaneously detect both creatinine (CREA) and urea until the concentration of CREA is lower than the certain level. To reduce urea testing, we suggest measuring urea only when CREA or estimated glomerular filtration rate (eGFR) exceeds a predetermined limit.