Serum Vitamin E Reference Intervals in a Black Congolese Population of Kinshasa

Context: Vitamin E is a powerful antioxidant and plays an important role in human reproduction. However, micronutrient deficiency is a major public health problem, particularly in developing countries. This study aimed to establish reference intervals (RIs) for vitamin E in black Congolese people of childbearing age using an ELISA method to provide a reference for clinically assessing vitamin E status. Methods: A total of 127 healthy people between the ages of 20 and 42 who underwent check-ups were randomly selected for the study. ELISA method measured the level of vitamin E. The effect of gender on vitamin E level was assessed, and RI was established using a parametric approach. Results: Women showed significantly higher levels of vitamin E than men (p = 0.01). The RI of vitamin E in people of childbearing age was 3.71 to 13.72, 4.52 to 14.64, and 4.17 to 13.52 mg/L, respectively, for the whole population, women and men. Conclusion: Using an ELISA method, this study established RI for vitamin E in the black Congolese population of childbearing age. We also found that women had significantly higher vitamin E levels than men. The results could provide a scientific basis for interpreting vitamin status in people of childbearing age in our setting.

Determination of reference intervals for metabolic profile of Hanwoo cows at early, middle and late gestation periods

Background： Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, there is little metabolic profile data available about Korean Hanwoo cows. Therefore, this study aimed to determine the reference intervals of metabolic profile for Korean Hanwoo cows. Methods： Healthy animals （2,205） were selected and divided into early （day 1 to 95）, middle （day 96 to 190） and late （day 191 to 285） period according to their gestating period. Metabolic profile including total protein （TP）, albumin （AIb）, urea （UREA）, glucose （Glu）, total cholesterol （T-Cho）, long-chain fatty acid （LCFA）, aspartate aminotransferase （AST）, gamma-glutamyl transpeptidase （GGT）, creatinine （Crea）, calcium （Ca）, inorganic phosphorous （iP） and magnesium （Mg） were analyzed using a TBA-4OFR automatic biochemical analyzer. The data of Korean Hanwoo cows were then compared to those of the Japanese Wagyu cows. Results： Most of the data of the Korean Hanwoo cows were relatively higher than those of Japanese Wagyu cows, with the exception of Glu and GGT. This may indicate that the nutritional level of feed for the Korean Hanwoo cows was higher than that of the Japanese Wagyu cows because of the different feeding system. In particular, relatively higher levels of UREA and LCFA were observed in the Korean Hanwoo cows, and this may also contribute to the low reproduction efficiency. Conclusions： These findings may provide some theoretical basis for understanding the reproductive and feeding situation of Korean Hanwoo cows.

Establishment of Reference Intervals and Transfusion Criterion for Sonoclot Analysis

Sonoclot analyzer has been widely used in many countries. But the reference intervals provided by the manufacturer were derived from only 45 participants, and there was no cut-off value for transfusion for Sonoclot analysis. This study aimed to establish reference intervals and transfusion criterion for Sonoclot analysis. Volunteers were recruited from healthy Chinese adults and patients undergoing cardiac surgery. Blood samples were withdrawn from forearm vein and measured for activated clotting time（ACT）, clot rate（CR）, platelet function（PF）, activated partial thromboplastin time（APTT）, fibrinogen concentration（FIB）, and platelet count（PLT）. The reference intervals were determined by the nonparametric method. Cut-off values were determined by the receiver operating characteristics curve. A total of 135 healthy volunteers and 281 patients were enrolled. The 95% reference intervals were 96–195 s, 22–51 signal U/min, 〉1.6 for ACT, CR, PF respectively. In the 281 patients, the results of APTT, FIB, PLT, ACT, CR, and PF ranged from 20.5–300.0 s, 0.28–4.11 g/L,（19.0–387.3）×109/L, 80–514 s, 2.9–74 signal U/min, and 0.1–5.1 respectively. The cut-off values for transfusion were 〉208, ≤14, and ≤1.3 for ACT, CR, PF respectively. The cut-off values of Sonoclot analysis were within the manufacturer＇s reference intervals, while they were outside the reference intervals established in this study. The results suggested that the manufacturer＇s reference intervals were not suitable for Chinese. The reference intervals and cut-off values established in this study will be helpful to Chinese patients.

Indirect determination of serum creatinine reference intervals in a Pakistani pediatric population using big data analytics

BACKGROUND The indirect methods of reference intervals(RI)establishment based on data mining are utilized to overcome the ethical,practical challenges and the cost associated with the conventional direct approach.AIM To generate RIs for serum creatinine in children and adolescents using an indirect statistical tool.METHODS Data mining of the laboratory information system was performed for serum creatinine analyzed from birth to 17 years for both genders.The timeline was set at six years from January 2013 to December 2018.Microsoft Excel 2010 and an indirect algorithm developed by the German Society of Clinical Chemistry and Laboratory Medicine’s Working Group on Guide Limits were used for the data analysis.RESULTS Data were extracted from 96104 samples and after excluding multiple samples for the same individual,we calculated RIs for 21920 males and 14846 females,with stratification into six discrete age groups.CONCLUSION Serum creatinine dynamics varied significantly across gender and age groups.

Hematologic and biochemical reference intervals for specific pathogen free 6-week-old Hampshire-Yorkshire crossbred pigs

Background： Hematologic and biochemical reference intervals depend on many factors, including age. A review of the literature highlights the lack of reference intervals for 6-wk-old specific pathogen free （SPF） Hampshire-Yorkshire crossbred pigs. For translational research, 6-wk-old pigs represent an important animal model for both human juvenile colitis and diabetes mellitus type 2 given the similarities between the porcine and human gastrointestinal maturation process. The aim of this study was to determine reference intervals for hematological and biochemical parameters in healthy 6-wk-old crossbred pigs. Blood samples were collected from 66 clinically healthy Hampshire-Yorkshire pigs. The pigs were 6 wks old, represented both sexes, and were housed in a SPF facility. Automated hematological and biochemical analysis were performed using an ADVIA 120 Hematology System and a Cobas 6000 C501 Clinical Chemistry Analyzer. Results： Reference intervals were calculated using both parametric and nonparametric methods. The mean, median, minimum, and maximum values were calculated. Conclusion： As pigs are used more frequently as medical models of human disease, having reference intervals for commonly measured hematological and biochemical parameters in 6-wk-old pigs will be useful. The reference intervals calculated in this study will aid in the diagnosis and monitoring of both naturally occurring and experimentally induced disease. In comparison to published reference intervals for older non SPF pigs, notable differences in leukocyte populations, and in levels of sodium, potassium, glucose, protein, and alkaline phosphatase were observed.

Proposed age-stratified reference intervals of FSH derived from normozoospermic men

Objective:To demonstrate that serum follicle-stimulating hormone(FSH)in men rises with age,and to explore FSH reference intervals of age-related partitioning.Methods:Men aged 20-50 years(n=1190)underwent semen analysis according to World Health Organization(2010)methods.Serum was frozen prior to measurement of FSH by using the Siemens ADVIA Centaur®XP immunoassay system.FSH central 95%intervals after logarithmic transformation based on age were derived from 1037 normozoospermic men.These were then applied to oligozoospermic and azoospermic men.Men producing azoospermic semen samples were further classified as having non-obstructive azoospermia by clinical diagnostic criteria,including genetic analysis and surgical exploration.Results:Serum FSH in normozoospermic men increased with age(P<0.05),and reference intervals were determined with 10-year brackets:21-30 years[(1.0-8.2)IU/L],31-40 years[(1.4-9.5)IU/L],41-50 years[(1.9-12.0)IU/L].The proportion of oligozoospermic men with normal FSH concentrations was less than the normozoospermic men,which in turn was lower among azoospermic men(both P<0.01).The azoospermic men were further broken down according to the nature of the azoospermia as either obstructive or non-obstructive azoospermia,and 86.4%(38/44)men with non-obstructive azoospermia had elevated serum FSH concentrations whereas only 6.7%(1/15)men with obstructive azoospermia had high FSH levels,and this was significantly different(P<0.01).Conclusions:FSH concentrations increase in men between 20-50 years,and clinical interpretation of serum FSH results in men must be made by using age-based reference intervals.

Comparison of the Reference Intervals Used for the Evaluation of Maternal Thyroid Function During Pregnancy Using Sequential and Nonsequential Methods

Background： Maternal thyroid dysfunction is common during pregnancy, and physiological changes during pregnancy can lead to the overdiagnosis of hyperthyroidism and misdiagnosis of hypothyroidism with nongestation-specific reference intervals. Our aim was to compare sequential with nonsequential methods for the evaluation of thyroid function in pregnant women. Methods： We tested pregnant women who underwent their trimester prenatal screening at our hospital from February 2011 to September 2012 for serum thyroid stimulating hormone （TSH） and free thyroxine （FT4） using the Abbott and Roche kits. There were 447 and 200 patients enrolled in the nonsequential and sequential groups, respectively. The central 95% range between the 2.5th and the 97.5th percentiles was used as the reference interval for the thyroid function parameter. Results： The nonsequential group exhibited a significantly larger degree of dispersion in the TSH reference interval during the 2nd and 3rd trimesters as measured using both the Abbott and Roche kits （all P 〈 0.05）. The TSH reference intervals were significantly larger in the nonsequential group than in the sequential group during the 3rd trimester as measured with both the Abbott （4.95 vs. 3.77 mU/L, P 〈 0.001） and Roche kits （6.62 vs. 5.01 mU/L, P〈 0.004）. The nonsequential group had a significantly larger FT4 reference interval as measured with the Abbott kit during all trimesters （ 12.64 vs. 5.82 pmol/L; 7,96 vs. 4.77 pmol/L; 8.10 vs. 4.77 pmol/L, respectively, all P 〈 0.05）, whereas a significantly larger FT4 reference interval was only observed during the 2nd trimester with the Roche kit （7.76 vs. 5.52 pmol/L, P = 0.002）. Conclusions： It was more reasonable to establish reference intervals for the evaluation of maternal thyroid function using the sequential method during each trimester of pregnancy. Moreover, the exclusion of pregnancy-related complications should be considered in the inclusion criteria for thyroid function tests.

Establishment of age-and gender-specific pediatric reference intervals for liver function tests in healthy Han children

Background The development and growth of children influence values of liver function tests.This study aims to establish age-and gender-specific pediatric reference intervals of liver function among Han children in Changchun,China.Methods A total of 1394 healthy Han children,aged 2-14 years,were recruited from communities and schools with informed parental consent in Changchun.The levels of serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),y-glutamyltransferase(GGT),alkaline phosphatase(ALP),total protein(TP),albumin(ALB),total bilirubin(TBIL)and direct bilirubin(DBIL)were measured on Hitachi 7600-210 automatic biochemical analyzer.The age-and gender-specific reference intervals were partitioned using Harris and Boyd's test and calculated using nonparametric rank method.The pediatric reference intervals were validated in five representative hospitals located in different areas in Changchun.Results All the analytes required some levels of age partitioning.Proteins(TP,ALB)and bilirubins(TBIL,DBIL)required no gender partitioning.In contrast,considerable gender partitioning was required for serum ALT,AST,GGT,and ALP.TP,TBIL,and DBIL showed steady increases,and AST showed apparent decreases over time,whereas ALT,GGT,ALP,and ALB demonstrated complex trends of change.ALT and GGT increased sharply in males from 11 to 14 years old.However,ALP declined in females from 13 to 14 years.All five laboratories passed the validation of reference intervals.Conclusions There were apparent age or gender variations of the reference intervals for liver function.When establishing pediatric reference intervals,partitioning according to age and gender is necessary.

Urinary cystatin C:pediatric reference intervals and comparative assessment as a biomarker of renal injury among children in the regions with high burden of CKDu in Sri Lanka

Background Cystatin C(Cys-C)is an emerging biomarker of renal diseases and its clinical use,particularly for screening the communities affected by chronic kidney disease of unknown etiology(CKDu),is hindered due to the lack of reference intervals(RIs)for diverse ethnic and age groups.The present study aimed to define RIs for urinary Cys-C(uCys-C)for a healthy pediatric population in Sri Lanka and in turn compare the renal function of the residential children in CKDu endemic and non-endemic regions in Sri Lanka.Methods A cross-sectional study was conducted with 850 healthy children(10-17 years)from selected locations for reference interval establishment,while a total of 892 children were recruited for the comparative study.Urine samples were collected and analyzed for Cys-C,creatinine(Cr)and albumin.Cr-adjusted uCys-C levels were partitioned by age,and RIs were determined with quantile regression(2.5th,50th and 97.5th quantiles)at 90%confidence interval.Results The range of median RIs for uCys-C in healthy children was 45.94-64.44 ng/mg Cr for boys and 53.58-69.97 ng/mg Cr for girls.The median(interquartile range)uCys-C levels of children in the CKDu endemic and non-endemic regions were 58.18(21.8-141.9)and 58.31(23.9-155.3)ng/mg Cr with no significant difference(P=0.781).A significant variation of uCys-C was noted in the children across age.Conclusions Notably high uCys-C levels were observed in children with elevated proteinuria.Thus,uCys-C could be a potential biomarker in identifying communities at high risk of CKDu susceptibility.

Pediatric-specifi c reference intervals in a nationally representative sample of Iranian children and adolescents: the CASPIAN-III study

Background:This study aimed to determine for the fi rst time the age-and gender-specific reference intervals for biomarkers of bone,metabolism,nutrition,and obesity in a nationally representative sample of the Iranian children and adolescents.Methods:We assessed the data of blood samples obtained from healthy Iranian children and adolescents,aged 7 to 19 years.The reference intervals of glucose,lipid profile,liver enzymes,zinc,copper,chromium,magnesium,and 25-hydroxy vitamin D[25(OH)D]were determined according to the Clinical&Laboratory Standards Institute C28-A3 guidelines.The reference intervals were partitioned using the Harris–Boyd method according to age and gender.Results:The study population consisted of 4800 school students(50%boys,mean age of 13.8 years).Twelve chemistry analyses were partitioned by age and gender,displaying the range of results between the 2.5th to 97.5th percentiles.Significant differences existed only between boys and girls at 18 to 19 years of age for low density lipoprotein-cholesterol.25(OH)D had the only reference interval that was similar to all age groups and both sexes.Conclusions:This study presented the first national database of reference intervals for a number of biochemical markers in Iranian children and adolescents.It is the fi rst report of its kind from the Middle East and North Africa.The fi ndings underscore the importance of providing reference intervals in different ethnicities and in various regions.