scholarly journals Establishing race-, gender- and age-specific reference intervals for pyridoxal 5′-phosphate in the NHANES population to better identify adult hypophosphatasia

Bone ◽  
2020 ◽  
Vol 141 ◽  
pp. 115577
Author(s):  
Marian Schini ◽  
Philip Nicklin ◽  
Richard Eastell
Keyword(s):  
Reference Intervals ◽  
Specific Reference ◽  
Gender And Age

scholarly journals Reference intervals for 33 biochemical analytes in healthy Indian population: C-RIDL IFCC initiative

2018 ◽  
Vol 56 (12) ◽  
pp. 2093-2103 ◽  
Author(s):  
Swarup A.V. Shah ◽  
Kiyoshi Ichihara ◽  
Alpa J. Dherai ◽  
Tester F. Ashavaid
Keyword(s):  
Parametric Method ◽  
Reference Intervals ◽  
Specific Reference ◽  
Appreciable Effect ◽  
Test Results ◽  
Gender And Age ◽  
Sources Of Variation ◽  
Overnight Fasting ◽  
Nested Analysis ◽  
Non Parametric

Abstract Background In 2011, the IFCC Committee on Reference Intervals and Decision Limits (C-RIDL) initiated a worldwide multicenter study on references values facilitating the implementation of country-specific reference intervals (RIs). There has been no well-designed RI study in India. This study aims to derive RIs for 33 major biochemical analytes in carefully selected healthy Indians as defined in C-RIDL protocol. Methods A total of 512 healthy Indians were recruited. Sera collected from overnight fasting blood samples were measured collectively for the analytes. Multiple regression analysis (MRA) and nested analysis of variance (ANOVA) were used to identify the potential sources of variation (SV) of test results. RI were derived by both parametric and non-parametric methods for comparison. The need for secondary exclusion by latent abnormal values exclusion (LAVE) method was examined. Results MRA results indicated that both age and BMI were apparent SV for many analytes in both sexes. ANOVA revealed that partition of RIs by gender and age was required for 17 analytes (TC, HDL-C, TG, hsCRP, ALB, AST, ALT, ALP, GGT, TBil, Urea, CRE, UA, Fe, TTR, CK and IgM) and 5 (Glu, ALB, TC, ALP and Urea), respectively. RIs by parametric method were generally narrower than by non-parametric method, reflecting distorted peripheral distributions of test results. The LAVE method had no appreciable effect on RIs possibly due to inconsistency among abnormal values of related analytes. Conclusions This study has for the first time provided comprehensive RIs information in healthy Indians. The final RIs adopted were those derived by parametric method without LAVE procedure.

Mining of hospital laboratory information systems: a model study defining age- and gender-specific reference intervals and trajectories for plasma creatinine in a pediatric population

2015 ◽  
Vol 53 (10) ◽  
Author(s):  
Karen Søeby ◽  
Peter Bjødstrup Jensen ◽  
Thomas Werge ◽  
Steen Sørensen
Keyword(s):  
Pediatric Population ◽  
Laboratory Data ◽  
Age Groups ◽  
Reference Intervals ◽  
Repeated Measurements ◽  
Plasma Creatinine ◽  
Specific Reference ◽  
Healthy Population ◽  
Hospital Laboratory ◽  
Gender And Age

AbstractThe knowledge of physiological fluctuation and variation of even commonly used biochemical quantities in extreme age groups and during development is sparse. This challenges the clinical interpretation and utility of laboratory tests in these age groups. To explore the utility of hospital laboratory data as a source of information, we analyzed enzymatic plasma creatinine as a model analyte in two large pediatric hospital samples.Plasma creatinine measurements from 9700 children aged 0–18 years were obtained from hospital laboratory databases and partitioned into high-resolution gender- and age-groups. Normal probability plots were used to deduce parameters of the normal distributions from healthy creatinine values in the mixed hospital datasets. Furthermore, temporal trajectories were generated from repeated measurements to examine developmental patterns in periods of changing creatinine levels.Creatinine shows great age dependence from birth throughout childhood. We computed and replicated 95% reference intervals in narrow gender and age bins and showed them to be comparable to those determined in healthy population studies. We identified pronounced transitions in creatinine levels at different time points after birth and around the early teens, which challenges the establishment and usefulness of reference intervals in those age groups.The study documents that hospital laboratory data may inform on the developmental aspects of creatinine, on periods with pronounced heterogeneity and valid reference intervals. Furthermore, part of the heterogeneity in creatinine distribution is likely due to differences in biological and chronological age of children and should be considered when using age-specific reference intervals.

Derivation of gender and age-specific reference intervals from fully normal Japanese individuals and the implications for health screening

2015 ◽  
Vol 447 ◽  
pp. 105-114 ◽  
Author(s):  
Minoru Yamakado ◽  
Kiyoshi Ichihara ◽  
Yoshiyuki Matsumoto ◽  
Yoshiki Ishikawa ◽  
Kiminori Kato ◽  
...  
Keyword(s):  
Reference Intervals ◽  
Health Screening ◽  
Specific Reference ◽  
Gender And Age ◽  
Normal Japanese

EXPRESS: Method dependent variation in TSH and FT4 reference intervals in pregnancy: a systematic review

2021 ◽  
pp. 000456322110269
Author(s):  
O E Okosieme ◽  
Medha Agrawal ◽  
Danyal Usman ◽  
Carol Evans
Keyword(s):  
Systematic Review ◽  
Reference Interval ◽  
First Trimester ◽  
Reference Intervals ◽  
Assay Method ◽  
Specific Reference ◽  
Upper Limits ◽  
Wide Range ◽  
Assay Methods ◽  
In Pregnancy

Background: Gestational TSH and FT4 reference intervals may differ according to assay method but the extent of variation is unclear and has not been systematically evaluated. We conducted a systematic review of published studies on TSH and FT4 reference intervals in pregnancy. Our aim was to quantify method-related differences in gestation reference intervals, across four commonly used assay methods, Abbott, Beckman, Roche, and Siemens. Methods: We searched the literature for relevant studies, published between January 2000 and December 2020, in healthy pregnant women without thyroid antibodies or disease. For each study, we extracted trimester-specific reference intervals (2.5–97.5 percentiles) for TSH and FT4 as well as the manufacturer provided reference interval for the corresponding non-pregnant population. Results: TSH reference intervals showed a wide range of study-to-study differences with upper limits ranging from 2.33 to 8.30 mU/L. FT4 lower limits ranged from 4.40–13.93 pmol/L, with consistently lower reference intervals observed with the Beckman method. Differences between non-pregnant and first trimester reference intervals were highly variable, and for most studies the TSH upper limit in the first trimester could not be predicted or extrapolated from non-pregnant values. Conclusions: Our study confirms significant intra and inter-method disparities in gestational thyroid hormone reference intervals. The relationship between pregnant and non-pregnant values is inconsistent and does not support the existing practice in some laboratories of extrapolating gestation references from non-pregnant values. Laboratories should invest in deriving method-specific gestation reference intervals for their population.

Evaluation of Thyroid Function in Pregnant Women Using Automated Immunoassays

2021 ◽  
Author(s):  
K Aaron Geno ◽  
Matthew S Reed ◽  
Mark A Cervinski ◽  
Robert D Nerenz
Keyword(s):  
Pregnant Women ◽  
Equilibrium Dialysis ◽  
Reference Interval ◽  
First Trimester ◽  
Reference Intervals ◽  
Free Thyroxine ◽  
Specific Reference ◽  
Childbearing Age ◽  
Thyroid Autoantibody ◽  
The Impact

Abstract Introduction Automated free thyroxine (FT4) immunoassays are widely available, but professional guidelines discourage their use in pregnant women due to theoretical under-recoveries attributed to increased thyroid hormone binding capacity and instead advocate the use of total T4 (TT4) or free thyroxine index (FTI). The impact of this recommendation on the classification of thyroid status in apparently euthyroid pregnant patients was evaluated. Methods After excluding specimens with thyroid autoantibody concentrations above reference limits, thyroid-stimulating hormone (TSH), FT4, TT4, and T-uptake were measured on the Roche Cobas® platform in remnant clinical specimens from at least 147 nonpregnant women of childbearing age and pregnant women at each trimester. Split-sample comparisons of FT4 as measured by the Cobas and equilibrium dialysis were performed. Results FT4 decreased with advancing gestational age by both immunoassay and equilibrium dialysis. TSH declined during the first trimester, remained constant in the second, and increased throughout the third, peaking just before delivery. Interpretation of TT4 concentrations using 1.5-times the nonpregnant reference interval classified 13.6% of first trimester specimens below the lower reference limit despite TSH concentrations within trimester-specific reference intervals. Five FTI results from 480 pregnant individuals (about 1.0%) fell outside the manufacturer’s reference interval. Conclusions Indirect FT4 immunoassay results interpreted in the context of trimester-specific reference intervals provide a practical and viable alternative to TT4 or FTI. Declining FT4 and increasing TSH concentrations near term suggest that declining FT4 is not an analytical artifact but represents a true physiological change in preparation for labor and delivery.

scholarly journals Effect of 1 mg/kg oral prednisolone on biochemical analytes in ten dogs: a cross-over study

2021 ◽  
Author(s):  
Helena Pettersson ◽  
Carl Ekstrand ◽  
Anna Hillström ◽  
Inger Lilliehöök
Keyword(s):  
Clinical Relevance ◽  
Control Period ◽  
Iron Concentration ◽  
Oral Prednisolone ◽  
Reference Intervals ◽  
Specific Reference ◽  
Test Results ◽  
Prednisolone Treatment ◽  
Anti Inflammatory ◽  
And Control

AbstractPrednisolone is used for treatment of inflammatory, allergic, neoplastic, and immune-mediated diseases in dogs. As a glucocorticoid, prednisolone has biochemical effects, which may interfere with the interpretation of biochemistry test results. The aim of this study is to investigate the effects of prednisolone treatment in an anti-inflammatory dose on common biochemical analytes in dogs and to evaluate the clinical relevance of the changes. Ten beagle dogs, enrolled in a cross-over study, were treated with oral prednisolone (1 mg/kg 24 h) for 10 days. Blood samples were collected at day 0, 1, 3, 6, 9, 10, 12, 16, and 20. Data was analyzed using a general linear model with time and treatment as fixed factors. Pairwise comparisons were done between prednisolone and control period for each dog and sampling. Significant results were further evaluated for clinical relevance using laboratory-specific reference intervals and reference change values (RCVs), when available. Statistically significant changes were observed for ALP activity and iron concentration, which increased to levels exceeding the RCV, and several results were outside reference intervals. Phosphate and bile acids increased significantly, while amylase, lipase, and cholesterol decreased significantly, but with mean/median results remaining within reference intervals. Anti-inflammatory prednisolone treatment did not induce significant changes in ALT, GLDH, GGT, cPLI, glucose, or calcium. Treatment with an anti-inflammatory dose of prednisolone induced changes in several analytes. Only the increases in ALP and iron were of such magnitude that they are expected to affect the clinical interpretation of test results.

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