Reference intervals of several renal and hepatic function parameters for apparently healthy adults from Eastern China

Reference intervals of biochemical analytes in healthy adults from northern China: A population-based cross-sectional study

Reference intervals (RIs) of laboratory testing play a fundamental role in medical activities. RIs vary greatly for populations in different areas This study aimed to evaluate the age- and sex-specific reference intervals for a healthy population in a typical city of northern China. A cross-sectional study was performed in 4 tertiary care centers of Shijiazhuang of China, biochemical analytes were analyzed using a Beckman Coulter AU5800 (Beckman Coulter Inc., Brea, CA). A total of 42,979 healthy individuals were involved in this study. Grouped by age- and sex-specific, reference intervals of all the measures have been established. We found that different age groups of males and females have significant differences (all P < .001) in levels of various biochemical analytes. We provided a comprehensive age- and sex-specific RIs for biochemical analytes, which showed dynamic changes with both age and sex. For the local population, the reference intervals established here can be adopted in other clinical laboratories after appropriate validation.

New comprehensive reference values for kidney function indexes across adult and geriatric ages in Chinese popuplation

Background and aims

China has the largest number of chronic kidney disease (CKD) patients. Current CKD definition has been challenged recently. We aim to reassess kidney function in healthy Chinese population, to provide a more appropriate reference range (RIs) for diagnosis, treatment, monitoring (or screening) of kidney disease and related research.

Materials and methods

A total of 49627 apparently healthy people aged 18-94 years old were enrolled. Age and sex effects were explored for the kidney function indicators and RIs were calculated non-parametrically.

Results

Albumin's limits were lower than the national RIs, with 5.7 g/L lower in upper limit (UL) and 0.4 g/L lower in lower limit (LL) [RIs: 39.6-49.3 vs 40-55]. The LL of estimate glomerular filtration rate (eGFR) was 80.4 mL/min/1.73 m² or 63.3 mL/min/1.73 m² at the age of <50 or ≥70 years, respectively. Notably, eGFR showed an approximately 0.7 mL/min/1.73 m² decrease every year. In addition, eGFR increase 0.35 mL/min/1.73 m² per standard deviation increase in blood glucose when uric acid (UA) exceed the RIs.

Conclusion

UA was an important factor affecting eGFR. For healthy elderly in China, albumin's limits were lower than the national RIs, and LLs of eGFR were nearly 60 mL/min/1.73 m². Using national RIs for healthy elderly may be overly stringent.

Establishment of gender- and age-specific reference intervals for serum liver function tests among the elderly population in northeast China: a retrospective study

Introduction

Reference intervals (RIs) for younger population may not apply to the elderly population. The aim of this study was to establish gender- and age-specific RIs for serum liver function tests among the elderly population and to compare with younger population RIs currently used in China and other countries.

Materials and methods

This was a retrospective study, and subjects (≥ 18 year-old) were recruited from the laboratory information system (LIS) at the First Hospital of Jilin University between April 2020 and April 2021. The following parameters were collected: aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), total bilirubin (TBIL), and direct bilirubin (DBIL). The Tukey method was used to eliminate outliers. Reference intervals were established by the nonparametric method.

Results

A total of 23,597 healthy individuals were enrolled in the study. From all parameters AST, ALT, TP and ALB required no gender partition, while ALT, GGT, TP, ALB and DBIL required different partitions for age. Activities and concentrations of ALT, ALB, and TP showed a downward trend in the elderly aged 60-89. In contrast, DBIL showed a gradual upward trend.

Conclusion

The RIs for liver function tests among healthy elderly population were different from those among young population in China. There were apparent gender and age differences in the RIs of liver function for elderly and significant differences compared with national standards and RIs in other countries. Therefore, it is necessary to establish gender- and age-specific RIs for serum liver function tests among the elderly population.

Establishment of dry chemistry based reference intervals of renal function test parameters for the adult population of Kaski District, Nepal

Background

Reference intervals (RIs) for clinical chemistry test parameters are specific to the method of measurement and population under service. However, there has been no locally available dry chemistry based RIs for the Nepalese population. Thus, the present study aimed to establish dry chemistry based RIs for sodium, potassium, urea, and creatinine specific to adult populations of Kaski districts, Nepal

Methods

This was a cross-sectional study conducted at the Manipal Teaching Hospital, Pokhara, Kaski, Nepal on 360 healthy adult participants aged 18–65 years. The test parameters under study were analyzed using a fully automated OCD Vitros 350 dry chemistry analyzer following the protocols provided by the reagent kit manufacturer. The RIs were estimated using reference limits at 2.5th and 97.5th percentiles. The normal distribution of the data was tested by Kolmogorov–Smirnov, and Shapiro–Wilk tests. The differences between males and females RIs were compared by the Mann-Whitney test while age-specific RIs for each sex was compared by One-Way-ANOVA and Dunnett’s Multiple Comparisons Tests. All the data were managed and analyzed using MS Excel and SPSS version 20.

Results

The RIs of urea, creatinine, sodium, and potassium specific to the adult population of Kaski district, Nepal are as follows: urea: 4.20–13.70 mmol/L (males: 4.70–13.99; females: 4.20–13.23); creatinine: 44.20–106.10 μmol/L (males: 48.82–106.10; females: 35.40–83.78); sodium 135–146 mmol/L (males: 135–146; females: 135–146) and potassium 3.60–5.10 mmol/L (males: 3.54–5.0; females: 3.60–5.10). These RIs were found to be different from currently used RIs provided by the reagent manufacturer. RIs of all the test parameters were significantly influenced by the age of the study participants. However, only the RIs of urea, creatinine, and potassium were significantly influenced by sex.

Conclusions

The present study has for the first time established dry chemistry based RIs for selected renal function test parameters specific to the adult population of Kaski district, Nepal. This result will aid the clinician in minimizing the errors in result interpretation and making a precise clinical decision.

Reference intervals of routine clinical chemistry parameters among apparently healthy young adults in Amhara National Regional State, Ethiopia

Background

Clinical laboratory reference intervals (RIs) are essential for clinical diagnosis, treatment and therapeutic monitoring. Locally established RIs are required to correctly interpret clinical laboratory results. In Ethiopia, clinical laboratory test results are interpreted based on RIs derived from a western population.

Methods

A multicenter cross-sectional study was conducted among blood donors in Amhara National Regional State, Ethiopia from March 2016 to May 2017. A total of 1,175 apparently healthy study participants were included in the study from four blood banks in the region. All clinical chemistry parameters were analyzed using Mindray BS-200E full automated clinical chemistry analyzer. The 95% RIs were estimated using reference limits at 2.5th percentile for the lower reference limit and 97.5th percentile for the upper reference limit. Kolmogorov–Sminorv and Wilcoxon rank-sum tests were used to check data distribution normality and whether partitions were needed between variables, respectively.

Results

RIs established include: ALT 5.13–42.88 U/L for males and 4.3–37 U/L for females; AST 12.13–46.88 for males and 10–43.8 U/L for females; ALP 77.2–475.8 U/L for males and 89–381 U/L for females; amylase 29–309.8 U/L for males and 29–287.9 U/L for females; GGT 7–69.8 U/L for males and 6–39.1 U/L for females; total bilirubin 0.11–1.18 mg/dl for males and 0.08–0.91 mg/dl for females; creatinine 0.48–1.13 mg/dl for males and 0.47–1.09 mg/dl for females; total cholesterol 78.13–211.75 mg/dl for males and 83.6–202.7 mg/dl for females; total protein 5.7–9.7 g/dl for males and 5.6–9.47 for females; triglycerides 36–221.9 mg/dl for males and 35.3–201.5 mg/dl for females; urea 12–43 mg/dl for males and 10–38.7 mg/dl for females; and uric acid 2.7–6.9 mg/dl for males and 2.1–5.9 mg/dl for females.

Conclusion

This study has established RIs for routine clinical chemistry parameters. These RIs are important as they support the interpretation of clinical laboratory results for medical decision making and other health-related activities.

Influence of non-pathological factors on ALT measurements

Alanine transaminase (ALT) is still the most sensitive marker for evaluating the damage of liver cells. ALT measurements may be affected by common non-pathological factors such as gender, age, pregnancy, different physiological conditions, circadian rhythm, diet, drinking, smoking, strenuous exercise, metabolic factors, drugs, blood collection methods, and specimen collection, transmission, and preservation. It is important to emphasize the definition of limits of normal ALT and the influence of the above-mentioned non-pathological factors on its test results.