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Background: Insulin is essential for glycemic regulation but diseases can cause a default or an excess of insulin secretion leading to dysregulated glycemia. Hence, measurement of insulinemia is useful to investigate hypoglycemia, determine the pathogenesis of diabetes and evaluate β-cell function. Thus, diabetic patients need supplementation with recombinant human insulin and/or insulin analogues. Analogues have primary sequences different from native human insulin and may not be detected by some immunoassays. The objective of our study was to evaluate new insulin immunoassays by determining their ability to detect different types of human insulin or analogues., Methods: This study compared the reactivity of two new insulin immunoassays with five well-established immunoassays on ten commercial insulins. We also measured insulin in blood samples from diabetic or pancreas transplant patients with known treatment., Results: Contrary to recombinant human insulin, there were differences in the specificity to insulin analogues. We distinguished three immunoassay categories: those recognizing all types of insulin such as the non-specific BI-INS-IRMA®, Architect® and Access® immunoassays; those recognizing human insulin only (Cobas®); and those recognizing human insulin and analogues in variable proportions (Liaison XL®, iFlash® and Maglumi®)., Conclusion: An accurate biological interpretation of insulinemia relies on knowledge of the specificity of the immunoassay used., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Apolipoproteins govern lipoprotein metabolism and are promising biomarkers of metabolic and cardiovascular diseases. Unlike immunoassays, MS enables the quantification and phenotyping of multiple apolipoproteins. Hence, here, we aimed to develop a LC-MS/MS assay that can simultaneously quantitate 18 human apolipoproteins [A-I, A-II, A-IV, A-V, B48, B100, C-I, C-II, C-III, C-IV, D, E, F, H, J, L1, M, and (a)] and determined apoE, apoL1, and apo(a) phenotypes in human plasma and serum samples. The plasma and serum apolipoproteins were trypsin digested through an optimized procedure and peptides were extracted and analyzed by LC-MS/MS. The method was validated according to standard guidelines in samples spiked with known peptide amounts. The LC-MS/MS results were compared with those obtained with other techniques, and reproducibility, dilution effects, and stabilities were also assessed. Peptide markers were successfully selected for targeted apolipoprotein quantification and phenotyping. After optimization, the assay was validated for linearity, lower limits of quantification, accuracy (biases: -14.8% to 12.1%), intra-assay variability [coefficients of variation (CVs): 1.5-14.2%], and inter-assay repeatability (CVs: 4.1-14.3%). Bland-Altman plots indicated no major statistically significant differences between LC-MS/MS and other techniques. The LC-MS/MS results were reproducible over five repeated experiments (CVs: 1.8-13.7%), and we identified marked differences among the plasma and serum samples. The LC-MS/MS assay developed here is rapid, requires only small sampling volumes, and incurs reasonable costs, thus making it amenable for a wide range of studies of apolipoprotein metabolism. We also highlight how this assay can be implemented in laboratories., (Copyright © 2020 Blanchard et al.)

Background: As being overweight can impair female spontaneous fertility or after assisted reproductive technology (ART) cycles, the aim of this study was to compare in vitro fertilization (IVF) outcome according to women's body mass index (BMI)., Methods: Retrospective study conducted from 2006 to 2009 in the IVF unit of Nantes University Hospital, France. 582 patients undergoing standard infertility workup and controlled ovarian stimulation were categorized according to BMI into two groups: group 1: normal weight (20-24.9 kg/m(2); n=409) and group 2: overweight and obese (≥25 kg/m(2); n=149). Basal hormonal status, smoking habitus, infertility duration, IVF cycle parameters and outcome were recorded., Results: Basal LH, FSH and estradiol levels were higher in group 1 than group 2, but ovarian reserve markers were comparable across the two BMI groups. Higher doses of gonadotropins were required in group 2 to obtain equivalent ovarian response than in group 1. No difference was observed on ovarian response and embryonic parameters. Cycle outcome were not significantly different between both groups, but we found a strong trend towards increasing transfer cancellation and miscarriage rates in group 2., Conclusion: Although overweight and obesity do not compromise ovarian stimulation results whenever adaptation of recombinant FSH doses is made, our data suggest an increased risk of cancellation transfer and miscarriage rate, leading to poorer IVF outcome., (Copyright © 2015 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Background: Numerous studies have evocated the clinical usefulness of serum AMH levels as a predictor of ovarian response and pregnancy in assisted reproductive technology cycles. Nevertheless, the analysis of the literature shows a great dispersion in serum AMH concentrations obtained with different methods from almost comparable populations., Methods: We compared two commercial immunoassays (AMH Beckman Coulter ELISA and AMH DSL ELISA) and we evaluated the AMH levels in serum as a prognosis value for ovarian response and pregnancy in assisted reproductive technology cycles., Results: We found a close linear relationship between the two methods but AMH levels were almost 4.6-fold lower with the DSL kit than with the Beckman Coulter kit. We found a significant and positive correlation between the number of mature ovocytes inseminated and AMH levels obtained with the two methods. Whatever the ELISA used, we found no significant difference between AMH level of pregnancy and non pregnancy groups. Indeed, using the Beckman Coulter method, all pregnant patients had serum AMH levels over 1.4 microg/L. Conversely, no cut-off value can be found for the DSL kit., Conclusion: Our results show clearly for the first time that AMH results are method dependent even if the correlation obtained between the two methods remained excellent. The Beckman Coulter AMH ELISA should produce clinical agreement when used for prognosis purposes on patients undergoing assisted reproduction.