scholarly journals SUN-LB46 Differences in IGF-I Concentrations Between European and US Populations - Consequences for Reference Intervals

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Martin Bidlingmaier ◽  
Andre Valcour ◽  
Kelly Y Chun ◽  
Katharina Schilbach ◽  
Tim Kühnle ◽  
...  
Keyword(s):  
Routine Data ◽  
Reference Intervals ◽  
Striking Difference ◽  
Specific Reference ◽  
Original Publication ◽  
Clin Pathol ◽  
Assay Performance ◽  
The Us ◽  
Igf I ◽  
The Difference

Abstract Background: IGF-I is the most widely used biomarker for management of GH related diseases. Reproducible assays and method-specific reference intervals (RIs) are crucial determinants of its clinical utility. Assay validation and RIs based on >15,000 subjects were published for the IDS iSYS IGF-I assay (J Clin Endocrinol Metab 2014). We now analyzed distribution of IGF-I results obtained in routine samples analyzed by accredited laboratories in the US and Europe, all using the IDS iSYS assay. Methods: All results from routine IGF-I measurements during the past 5 years in 4 laboratories were included (US lab n=778,173 males/710,752 females; European labs (Germany/Belgium, n=23,220 males/40,183 females). Assay performance across laboratories was confirmed through proficiency testing schemes and exchange of patient samples. We constructed RIs adjusted for age/sex from European and US cohorts separately using a modified Hoffmann approach (Am J Clin Pathol 2015), and compared to the originally published RIs (n=6697 males/8317 females, adults from Europe). A subset of US samples was used to compare IGF-I between regions with lower (Colorado) and higher (Alabama) mean body mass index (BMI). Results: Lower limits (LLs) of RIs calculated from routine results are superimposable to LLs from the original publication for all ages and sexes, regardless whether IGF-I results were from Europe or the US. For groups with sufficient n, upper limits (ULs) of RIs calculated from European routine data were also not statistically different from the originally published central 95%. However, a striking difference exists in calculated ULs from data of European and US origin: For ages 10-18 years, calculated UL on average was 149.3 ng/mL (34.6%) higher in boys and 94.9 ng/mL (19.8%) in girls from the US. In adults (19-95 years), calculated UL on average was 45 ng/mL (20.3%) higher in males and 29.7 ng/mL (13.8%) in females from the US. Within the US, mean IGF-I was significantly higher in samples from Colorado (lower mean BMI) than in Alabama (p<0.0001) across age- and sex groups, although the difference between the two states was smaller than between each of them and Europe. Conclusion: This study provides evidence that in sufficiently large datasets, both, direct sampling (as in the original publication) and the indirect Hoffmann algorithms provide statistically comparable RI limits and may be considered as accurate representation of results distribution in the disease-free populations. More importantly, we demonstrate that even with tight cross-correlation and continuous monitoring of IGF-I assay performance RIs generated in different populations can be different. Notably, in our extremely large study, the difference between Europe and the US was clinically relevant only at the UL. Although our study cannot reveal the cause of the difference, we suggest using adapted RIs for the US.

scholarly journals Effect of Sex and Assay Method on Serum Concentrations of Growth Hormone in Patients with Acromegaly and in Healthy Controls

2006 ◽  
Vol 52 (3) ◽  
pp. 468-473 ◽  
Author(s):  
Helene Markkanen ◽  
Tuula Pekkarinen ◽  
Matti J Välimäki ◽  
Henrik Alfthan ◽  
Ritva Kauppinen-Mäkelin ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Tolerance Test ◽  
Reference Intervals ◽  
Assay Method ◽  
Specific Reference ◽  
Oral Glucose ◽  
Serum Samples ◽  
Serum Growth Hormone ◽  
The Difference

Abstract Background: Diagnosis and follow-up of acromegaly is based on measurements of serum growth hormone (GH) concentrations during an oral glucose tolerance test (OGTT). A nadir value <1 μg/L is commonly used to define a normal response, but some authors suggest lower cutoff values. Methods: To compare the results and subsequent patient classification obtained with 3 GH assays, we obtained basal serum samples from 78 apparently healthy adult controls (43 women and 35 men; median age, 32.5 years) and from 71 treated (44 women and 27 men; median age, 55.2 years) and 7 untreated acromegaly patients (4 women and 3 men; median age, 54.6 years), and OGTT was performed on all patients and on 72 of the 78 controls. GH was determined by 2 immunometric assays—a double monoclonal (AutoDELFIA; Wallac) and a monopolyclonal (Immulite 2000; DPC) assay—and in a limited set of samples by an RIA (Spectria RIA; Orion). Results: There was a strong correlation (r = 0.995; P <0.001) between the 2 immunometric methods, but the results obtained with the Immulite 2000 were, on average, 1.4-fold higher than those obtained with the AutoDELFIA. At concentrations around the cutoff (1 μg/L), however, the difference was ∼2-fold. Overall, the Orion RIA method also showed a good correlation (r = 0.951–0.959) with the other methods, but it did not measure concentrations <2 μg/L. Women had higher basal and OGTT nadir GH concentrations than men. Conclusion: Reference intervals should be determined separately for each method, and the need for establishing sex-specific reference values should be investigated.

scholarly journals Estimation of Age-specific Reference Intervals for Skewed Data

2002 ◽  
Vol 41 (02) ◽  
pp. 147-153 ◽  
Author(s):  
M. A. A. Moussa
Keyword(s):  
Loss Function ◽  
Age Groups ◽  
Reference Intervals ◽  
The Body ◽  
Maximum Likelihood Estimates ◽  
Specific Reference ◽  
Regression Techniques ◽  
Lms Method ◽  
The Difference ◽  
Index Weight

Summary Objectives: To compare Cole’s LMS method with Wright and Royston’s Exponential-Normal (EN) method for estimating reference intervals and generating smooth centile curves for the body mass index (weight in kg/height in meters squared) measurements of children aged 6 to 13 years. Methods: In the LMS method, the parameters L (the power needed to normalize the data), M (median) and S (coefficient of variation) are modeled as smoothed fits of maximum likelihood estimates. In the Exponential-Normal method, the three parameters mean, standard deviation and skewness are estimated separately using multiple regression techniques. Results: The centiles generated by the LMS and EN methods are close in most of the age groups. The 2.5th and 97.5th quantiles of the interval of the differences between the loss function scores of the LMS and EN methods calculated by bootstrap was found to include zero, indicating that the difference in loss function scores of the two methods is random and not systematic. Conclusions: The two methods are simple to use and generate comparable centile curves.

Studi Eksegetis Yohanes 1:1-18 Sebagai Apologetik Terhadap Kristologi Saksi Yehuwa

2016 ◽  
Vol 1 (2) ◽  
pp. 1-41
Author(s):  
Pangeran Manurung
Keyword(s):  
Striking Difference ◽  
Human Being ◽  
John 1 ◽  
Jehovah’S Witnesses ◽  
Jehovah's Witnesses ◽  
Jehovah's Witness ◽  
Search Results ◽  
The Bible ◽  
God The Father ◽  
The Difference

Eksegesa John 1 : 1-18 shows that the Jehovah's Witness teachings deviate from the truth of the Bible and dangerous for Christians . The danger Christology of Jehovah's Witnesses should be bringing us to the prudence and discretion to reject it . It can be said that Jehovah's Witnesses do not include Christianity in accordance with the search results against their teachings . first ; they do not recognize the Bible that has been issued by the Indonesian National Bible Institute and consider if the Bible has too much harm to use their own New Translation of the Holy Scriptures that have been proven not a translation , but just a collection of interpretations and teachings of their leader alone . second ; Jehovah's Witnesses do not acknowledge Jesus as Lord and Savior only . They simply believe that salvation is obtained through belief in Jehovah and his kingdom and perform service message and follow the trial associations .                Before errors interfere Christology Christology of Jehovah's Witnesses Bible , please note that the topic of Christology is the difference between Christianity and other religions . This discussion has also become one of the topics that face many attacks from the outside or from within Christianity , either in the form of religion , philosophy , and ideology . The debate on this topic appeared since the beginning of Christianity , and give rise to a long and complex debate for nearly three centuries ( 300 years ) !! . Such debates will continue to exist throughout the period and just a rehash issues that had once appeared . And Christians should study the various debates and views of the ever emerging that are not easily fooled by the views back to this era .Eksegesa John 1 : 1-18 has been done and produce a biblical Christology and biblical correct . The truth is not in doubt because of the analysis conducted in accordance with the procedures and rules that apply in general . Now if Christology Christology of John compared with Jehovah's Witnesses, it will show a striking difference . Once observed , Christology Witnesses builds upon the interpretation of individuals who previously have had a negative Christological doctrine .                Conclusion those who think that Jesus is the firstborn of Creation ; Jesus was a human being ; Jesus is God in creating a peer ; Jesus lower than God , Jesus is the Angel Gabriel , and other Christological doctrine which basically degrading nature of Christ is a form of insult to the majesty of Christ . The Bible clearly and emphatically teaches that Christ is God incarnate , private alpha and omega , the creator of all that exists , and the equivalent of God the Father . Summing Christ as superior human or clear eldest creation is false teachings . The followers of Jehovah's Witnesses must repent. Amen

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.

scholarly journals Regulating health professional scopes of practice: comparing institutional arrangements and approaches in the US, Canada, Australia and the UK

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kathleen Leslie ◽  
Jean Moore ◽  
Chris Robertson ◽  
Douglas Bilton ◽  
Kristine Hirschkorn ◽  
...  
Keyword(s):  
Health Professional ◽  
Health Professionals ◽  
Swot Analysis ◽  
Institutional Arrangements ◽  
Scope Of Practice ◽  
Comparative Case Study ◽  
Specific Reference ◽  
The Public ◽  
The Us ◽  
The Uk

Abstract Background Fundamentally, the goal of health professional regulatory regimes is to ensure the highest quality of care to the public. Part of that task is to control what health professionals do, or their scope of practice. Ideally, this involves the application of evidence-based professional standards of practice to the tasks for which health professional have received training. There are different jurisdictional approaches to achieving these goals. Methods Using a comparative case study approach and similar systems policy analysis design, we present and discuss four different regulatory approaches from the US, Canada, Australia and the UK. For each case, we highlight the jurisdictional differences in how these countries regulate health professional scopes of practice in the interest of the public. Our comparative Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis is based on archival research carried out by the authors wherein we describe the evolution of the institutional arrangements for form of regulatory approach, with specific reference to scope of practice. Results/conclusions Our comparative examination finds that the different regulatory approaches in these countries have emerged in response to similar challenges. In some cases, ‘tasks’ or ‘activities’ are the basis of regulation, whereas in other contexts protected ‘titles’ are regulated, and in some cases both. From our results and the jurisdiction-specific SWOT analyses, we have conceptualized a synthesized table of leading practices related to regulating scopes of practice mapped to specific regulatory principles. We discuss the implications for how these different approaches achieve positive outcomes for the public, but also for health professionals and the system more broadly in terms of workforce optimization.

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