Prevalence of Distal Symmetrical Polyneuropathy by Diabetes Prevention Program Treatment Group, Diabetes Status, Duration of Diabetes, and Cumulative Glycemic Exposure.

OBJECTIVE: To assess associations between distal symmetric polyneuropathy (DSPN) and Diabetes Prevention Program (DPP) treatment groups, diabetes status or duration, and cumulative glycemic exposure approximately 21 years after DPP randomization. RESEARCH DESIGN AND METHODS: In the DPP, 3,234 adults ≥25 years old at high risk for diabetes were randomized to an intensive lifestyle (ILS), metformin, or placebo intervention to prevent diabetes. After the DPP ended, 2,779 joined the Diabetes Prevention Program Outcomes Study (DPPOS). Open-label metformin was continued, placebo was discontinued, ILS was provided in the form of semiannual group-based classes, and all participants were offered quarterly lifestyle classes. Symptoms and signs of DSPN were assessed in 1,792 participants at DPPOS year 17. Multivariable logistic regression models were used to evaluate DSPN associations with treatment group, diabetes status/duration, and cumulative glycemic exposure. RESULTS: At 21 years after DPP randomization, 66% of subjects had diabetes. DSPN prevalence did not differ by initial DPP treatment assignment (ILS 21.5%, metformin 21.5%, and placebo 21.9%). There was a significant interaction between treatment assignment to ILS and age (P < 0.05) on DSPN. At DPPOS year 17, the odds ratio for DSPN in comparison with ILS with placebo was 17.4% (95% CI 3.0, 29.3) lower with increasing 5-year age intervals. DSPN prevalence was slightly lower for those at risk for diabetes (19.6%) versus those with diabetes (22.7%) and was associated with longer diabetes duration and time-weighted HbA1c (P values <0.001). CONCLUSIONS: The likelihood of DSPN was similar across DPP treatment groups but higher for those with diabetes, longer diabetes duration, and higher cumulative glycemic exposure. ILS may have long-term benefits on DSPN for older adults.

GAD65Abs Are Not Associated With Beta-Cell Dysfunction in Patients With T2D in the GRADE Study.

Context: Autoantibodies directed against the 65-kilodalton isoform of glutamic acid decarboxylase (GAD65Abs) are markers of autoimmune type 1 diabetes (T1D) but are also present in patients with Latent Autoimmune Diabetes of Adults and autoimmune neuromuscular diseases, and also in healthy individuals. Phenotypic differences between these conditions are reflected in epitope-specific GAD65Abs and anti-idiotypic antibodies (anti-Id) against GAD65Abs. We previously reported that 7.8% of T2D patients in the GRADE study have GAD65Abs but found that GAD65Ab positivity was not correlated with beta-cell function, glycated hemoglobin (HbA1c), or fasting glucose levels. Context: In this study, we aimed to better characterize islet autoantibodies in this T2D cohort. This is an ancillary study to NCT01794143. Methods: We stringently defined GAD65Ab positivity with a competition assay, analyzed GAD65Ab-specific epitopes, and measured GAD65Ab-specific anti-Id in serum. Results: Competition assays confirmed that 5.9% of the patients were GAD65Ab positive, but beta-cell function was not associated with GAD65Ab positivity, GAD65Ab epitope specificity or GAD65Ab-specific anti-Id. GAD65-related autoantibody responses in GRADE T2D patients resemble profiles in healthy individuals (low GAD65Ab titers, presence of a single autoantibody, lack of a distinct epitope pattern, and presence of anti-Id to diabetes-associated GAD65Ab). In this T2D cohort, GAD65Ab positivity is likely unrelated to the pathogenesis of beta-cell dysfunction. Conclusion: Evidence for islet autoimmunity in the pathophysiology of T2D beta-cell dysfunction is growing, but T1D-associated autoantibodies may not accurately reflect the nature of their autoimmune process.

Impact of Insulin Sensitivity and ß-Cell Function Over Time on Glycemic Outcomes in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE): Differential Treatment Effects of Dual Therapy.

OBJECTIVE: To compare the effects of insulin sensitivity and ß-cell function over time on HbA1c and durability of glycemic control in response to dual therapy. RESEARCH DESIGN AND METHODS: GRADE participants were randomized to glimepiride (n = 1,254), liraglutide (n = 1,262), or sitagliptin (n = 1,268) added to baseline metformin and followed for mean ± SD 5.0 ± 1.3 years, with HbA1c assessed quarterly and oral glucose tolerance tests at baseline, 1, 3, and 5 years. We related time-varying insulin sensitivity (HOMA 2 of insulin sensitivity [HOMA2-%S]) and early (0-30 min) and total (0-120 min) C-peptide (CP) responses to changes in HbA1c and glycemic failure (primary outcome HbA1c ≥7% [53 mmol/mol] and secondary outcome HbA1c >7.5% [58 mmol/mol]) and examined differential treatment responses. RESULTS: Higher HOMA2-%S was associated with greater initial HbA1c lowering (3 months) but not subsequent HbA1c rise. Greater CP responses were associated with a greater initial treatment response and slower subsequent HbA1c rise. Higher HOMA2-%S and CP responses were each associated with lower risk of primary and secondary outcomes. These associations differed by treatment. In the sitagliptin group, HOMA2-%S and CP responses had greater impact on initial HbA1c reduction (test of heterogeneity, P = 0.009 HOMA2-%S, P = 0.018 early CP, P = 0.001 total CP) and risk of primary outcome (P = 0.005 HOMA2-%S, P = 0.11 early CP, P = 0.025 total CP) but lesser impact on HbA1c rise (P = 0.175 HOMA2-%S, P = 0.006 early CP, P < 0.001 total CP) in comparisons with the glimepiride and liraglutide groups. There were no differential treatment effects on secondary outcome. CONCLUSIONS: Insulin sensitivity and ß-cell function affected treatment outcomes irrespective of drug assignment, with greater impact in the sitagliptin group on initial (short-term) HbA1c response in comparison with the glimepiride and liraglutide groups.

Longitudinal Effects of Glucose-Lowering Medications on ß-Cell Responses and Insulin Sensitivity in Type 2 Diabetes: The GRADE Randomized Clinical Trial.

OBJECTIVE: To compare the long-term effects of glucose-lowering medications (insulin glargine U-100, glimepiride, liraglutide, and sitagliptin) when added to metformin on insulin sensitivity and ß-cell function. RESEARCH DESIGN AND METHODS: In the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) cohort with type 2 diabetes (n = 4,801), HOMA2 was used to estimate insulin sensitivity (HOMA2-%S) and fasting ß-cell function (HOMA2-%B) at baseline and 1, 3, and 5 years on treatment. Oral glucose tolerance test ß-cell responses (C-peptide index [CPI] and total C-peptide response [incremental C-peptide/incremental glucose over 120 min]) were evaluated at the same time points. These responses adjusted for HOMA2-%S in regression analysis provided estimates of ß-cell function. RESULTS: HOMA2-%S increased from baseline to year 1 with glargine and remained stable thereafter, while it did not change from baseline in the other treatment groups. HOMA2-%B and C-peptide responses were increased to variable degrees at year 1 in all groups but then declined progressively over time. At year 5, CPI was similar between liraglutide and sitagliptin, and higher for both than for glargine and glimepiride [0.80, 0.87, 0.74, and 0.64 (nmol/L)/(mg/dL) * 100, respectively; P < 0.001], while the total C-peptide response was greatest with liraglutide, followed in descending order by sitagliptin, glargine, and glimepiride [1.54, 1.25, 1.02, and 0.87 (nmol/L)/(mg/dL) * 100, respectively, P < 0.001]. After adjustment for HOMA2-%S to obtain an estimate of ß-cell function, the nature of the change in ß-cell responses reflected those in ß-cell function. CONCLUSIONS: The differential long-term effects on insulin sensitivity and ß-cell function of four different glucose-lowering medications when added to metformin highlight the importance of the loss of ß-cell function in the progression of type 2 diabetes.

Autologous Skin Cell Suspension for Full-Thickness Skin Defect Reconstruction: Current Evidence and Health Economic Expectations.

Despite differing etiologies, acute thermal burn injuries and full-thickness (FT) skin defects are associated with similar therapeutic challenges. When not amenable to primary or secondary closure, the conventional standard of care (SoC) treatment for these wound types is split-thickness skin grafting (STSG). This invasive procedure requires adequate availability of donor skin and is associated with donor site morbidity, high healthcare resource use (HCRU), and costs related to prolonged hospitalization. As such, treatment options that can facilitate effective healing and donor skin sparing have been highly anticipated. The RECELL® Autologous Cell Harvesting Device facilitates preparation of an autologous skin cell suspension (ASCS) for the treatment of acute thermal burns and FT skin defects. In initial clinical trials, the approach showed superior donor skin-sparing benefits and comparable wound healing to SoC STSG among patients with acute thermal burn injuries. These findings led to approval of RECELL for this indication by the US Food and Drug Administration (FDA) in 2018. Subsequent clinical evaluation in non-thermal FT skin wounds showed that RECELL, when used in combination with widely meshed STSG, provides donor skin-sparing advantages and comparable healing outcomes compared with SoC STSG. As a result, the device received FDA approval in June of 2023 for treatment of FT skin defects caused by traumatic avulsion or surgical excision or resection. Given that health economic advantages have been demonstrated for RECELL ± STSG versus STSG alone when used for burn therapy, it is prudent to examine similarities in the burn and FT skin defect treatment pathways to forecast the potential health economic advantages for RECELL when used in FT skin defects. This article discusses the parallels between the two indications, the clinical outcomes reported for RECELL, and the HCRU and cost benefits that may be anticipated with use of the device for non-thermal FT skin defects.

RIPK3 promotes islet amyloid-induced ß-cell loss and glucose intolerance in a humanized mouse model of type 2 diabetes.

OBJECTIVE: Aggregation of human islet amyloid polypeptide (hIAPP), a ß-cell secretory product, leads to islet amyloid deposition, islet inflammation and ß-cell loss in type 2 diabetes (T2D), but the mechanisms that underlie this process are incompletely understood. Receptor interacting protein kinase 3 (RIPK3) is a pro-death signaling molecule that has recently been implicated in amyloid-associated brain pathology and ß-cell cytotoxicity. Here, we evaluated the role of RIPK3 in amyloid-induced ß-cell loss using a humanized mouse model of T2D that expresses hIAPP and is prone to islet amyloid formation. METHODS: We quantified amyloid deposition, cell death and caspase 3/7 activity in islets isolated from WT, Ripk3-/-, hIAPP and hIAPP; Ripk3-/- mice in real time, and evaluated hIAPP-stimulated inflammation in WT and Ripk3-/- bone marrow derived macrophages (BMDMs) in vitro. We also characterized the role of RIPK3 in glucose stimulated insulin secretion (GSIS) in vitro and in vivo. Finally, we examined the role of RIPK3 in high fat diet (HFD)-induced islet amyloid deposition, ß-cell loss and glucose homeostasis in vivo. RESULTS: We found that amyloid-prone hIAPP mouse islets exhibited increased cell death and caspase 3/7 activity compared to amyloid-free WT islets in vitro, and this was associated with increased RIPK3 expression. hIAPP; Ripk3-/- islets were protected from amyloid-induced cell death compared to hIAPP islets in vitro, although amyloid deposition and caspase 3/7 activity were not different between genotypes. We observed that macrophages are a source of Ripk3 expression in isolated islets, and that Ripk3-/- BMDMs were protected from hIAPP-stimulated inflammatory gene expression (Tnf, Il1b, Nos2). Following 52 weeks of HFD feeding, islet amyloid-prone hIAPP mice exhibited impaired glucose tolerance and decreased ß-cell area compared to WT mice in vivo, whereas hIAPP; Ripk3-/- mice were protected from these impairments. CONCLUSIONS: In conclusion, loss of RIPK3 protects from amyloid-induced inflammation and islet cell death in vitro and amyloid-induced ß-cell loss and glucose intolerance in vivo. We propose that therapies targeting RIPK3 may reduce islet inflammation and ß-cell loss and improve glucose homeostasis in the pathogenesis of T2D.

Human islet amyloid polypeptide-induced ß-cell cytotoxicity is linked to formation of α-sheet structure.

Type 2 diabetes (T2D) results from insulin secretory dysfunction arising in part from the loss of pancreatic islet ß-cells. Several factors contribute to ß-cell loss, including islet amyloid formation, which is observed in over 90% of individuals with T2D. The amyloid is comprised of human islet amyloid polypeptide (hIAPP). Here we provide evidence that early in aggregation, hIAPP forms toxic oligomers prior to formation of amyloid fibrils. The toxic oligomers contain α-sheet secondary structure, a nonstandard secondary structure associated with toxic oligomers in other amyloid diseases. De novo, synthetic α-sheet compounds designed to be nontoxic and complementary to the α-sheet structure in the toxic oligomers inhibit hIAPP aggregation and neutralize oligomer-mediated cytotoxicity in cell-based assays. In vivo administration of an α-sheet design to mice for 4 weeks revealed no evidence of toxicity nor did it elicit an immune response. Furthermore, the α-sheet designs reduced endogenous islet amyloid formation and mitigation of amyloid-associated ß-cell loss in cultured islets isolated from an hIAPP transgenic mouse model of islet amyloidosis. Characterization of the involvement of α-sheet in early aggregation of hIAPP and oligomer toxicity contributes to elucidation of the molecular mechanisms underlying amyloid-associated ß-cell loss.

A retrospective analysis of mortality risk and immunosuppressive therapy for Stevens-Johnson Syndrome and toxic epidermal necrolysis syndrome using the TriNetX research network.

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) exist on a spectrum of autoimmune conditions which cause epidermal detachment and keratinocyte necrosis. Due to the rare incidence of these conditions, a dramatic heterogeneity in treatment algorithms exists. To better appreciate pharmacologic immunosuppressive therapies' impact on survival, the authors queried a multi-institutional data network. Data for this study was extracted from TriNetX Research Network, a platform that contains ICD-9/ICD-10 coding data from a consortium of international healthcare organizations. Seventy-one institutions were queried to identify adult patients diagnosed with SJS, TEN or SJS-TEN Overlap. Cohorts were created based on the therapy received: systemic steroids (SS), diphenhydramine (DH), cyclosporine (CS), intravenous immunoglobulin (IVIG), tumor necrosis factor alpha inhibitors (TNFαi), or a combination of treatments. Cohorts were then propensity matched with patients who received supportive care. Patients who only received one of the above treatments showed no significant reduction in 90-day mortality. Patients who received CS or IVIG as part of their multitherapy showed a significantly increased risk of death when compared to supportive care (CS: RR = 1.583, 95% CI [1.119, 2.240]; IVIG: RR = 2.132, 95% CI [1.485, 3.059]). Despite their frequent utilization, this study's analysis suggests that none of these therapies confer significant 90-day mortality survival over supportive care alone. These results highlight the heterogeneity of therapies and emphasize the need for critical prospective appraisal of their outcomes in SJS and TEN.

Comparison of tirzepatide and dulaglutide on major adverse cardiovascular events in participants with type 2 diabetes and atherosclerotic cardiovascular disease: SURPASS-CVOT design and baseline characteristics.

BACKGROUND: Tirzepatide, a once-weekly GIP/GLP-1 receptor agonist, reduces blood glucose and body weight in people with type 2 diabetes. The cardiovascular (CV) safety and efficacy of tirzepatide have not been definitively assessed in a cardiovascular outcomes trial. METHODS: Tirzepatide is being studied in a randomized, double-blind, active-controlled CV outcomes trial. People with type 2 diabetes aged ≥40 years, with established atherosclerotic CV disease, HbA1c ≥7% to ≤10.5%, and body mass index ≥25 kg/m2 were randomized 1:1 to once weekly subcutaneous injection of either tirzepatide up to 15 mg or dulaglutide 1.5 mg. The primary outcome is time to first occurrence of any major adverse cardiovascular event (MACE), defined as CV death, myocardial infarction, or stroke. The trial is event-driven and planned to continue until ≥1,615 participants experience an adjudication-confirmed component of MACE. The primary analysis is noninferiority for time to first MACE of tirzepatide vs dulaglutide by demonstrating an upper confidence limit <1.05, which will also confirm superiority vs a putative placebo, and also to determine whether tirzepatide produces a greater CV benefit than dulaglutide (superiority analysis). RESULTS: Over 2 years, 13,299 people at 640 sites in 30 countries across all world regions were randomized. The mean age of randomized participants at baseline was 64.1 years, diabetes duration 14.7 years, HbA1c 8.4%, and BMI 32.6 kg/m2. Overall, 65.0% had coronary disease, of whom 47.3% reported prior myocardial infarction and 57.4% had prior coronary revascularization. 19.1% of participants had a prior stroke and 25.3% had peripheral artery disease. The trial is fully recruited and ongoing. CONCLUSION: SURPASS-CVOT will provide definitive evidence as to the CV safety and efficacy of tirzepatide as compared with dulaglutide, a GLP-1 receptor agonist with established CV benefit.

Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes.

BACKGROUND: Semaglutide, a glucagon-like peptide-1 receptor agonist, has been shown to reduce the risk of adverse cardiovascular events in patients with diabetes. Whether semaglutide can reduce cardiovascular risk associated with overweight and obesity in the absence of diabetes is unknown. METHODS: In a multicenter, double-blind, randomized, placebo-controlled, event-driven superiority trial, we enrolled patients 45 years of age or older who had preexisting cardiovascular disease and a body-mass index (the weight in kilograms divided by the square of the height in meters) of 27 or greater but no history of diabetes. Patients were randomly assigned in a 1:1 ratio to receive once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. The primary cardiovascular end point was a composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke in a time-to-first-event analysis. Safety was also assessed. RESULTS: A total of 17,604 patients were enrolled; 8803 were assigned to receive semaglutide and 8801 to receive placebo. The mean (±SD) duration of exposure to semaglutide or placebo was 34.2±13.7 months, and the mean duration of follow-up was 39.8±9.4 months. A primary cardiovascular end-point event occurred in 569 of the 8803 patients (6.5%) in the semaglutide group and in 701 of the 8801 patients (8.0%) in the placebo group (hazard ratio, 0.80; 95% confidence interval, 0.72 to 0.90; P<0.001). Adverse events leading to permanent discontinuation of the trial product occurred in 1461 patients (16.6%) in the semaglutide group and 718 patients (8.2%) in the placebo group (P<0.001). CONCLUSIONS: In patients with preexisting cardiovascular disease and overweight or obesity but without diabetes, weekly subcutaneous semaglutide at a dose of 2.4 mg was superior to placebo in reducing the incidence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke at a mean follow-up of 39.8 months. (Funded by Novo Nordisk; SELECT ClinicalTrials.gov number, NCT03574597.).

Surviving Sepsis After Burn Campaign.

INTRODUCTION: The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes. METHODS: The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported. RESULTS: The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis. CONCLUSION: Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

SARS-CoV-2 infection is associated with higher odds of insulin treatment but not with hemoglobin A1c at 120 days in U.S. Veterans with new-onset diabetes.

Aims: To examine associations of SARS-CoV-2 infection/COVID-19 with insulin treatment in new-onset diabetes. Methods: We conducted a retrospective cohort study using Veterans Health Administration data (March 1, 2020-June 1, 2022). Individuals with ≥1 positive nasal swab for SARS-CoV-2 (n = 6,706) comprised the exposed group, and individuals with no positive swab and ≥1 laboratory test of any type (n = 20,518) the unexposed group. For exposed, the index date was the date of first positive swab, and for unexposed a random date during the month of the qualifying laboratory test. Among Veterans with new-onset diabetes after the index date, we modeled associations of SARS-CoV-2 with most recent A1c prior to insulin treatment or end of follow-up and receipt of >1 outpatient insulin prescription starting within 120 days. Results: SARS-CoV-2 was associated with a 40% higher odds of insulin treatment compared to no positive test (95%CI 1.2-1.8) but not with most recent A1c (ß 0.00, 95%CI -0.04-0.04). Among Veterans with SARS-CoV-2, ≥2 vaccine doses prior to the index date was marginally associated with lower odds of insulin treatment (OR 0.6, 95%CI 0.3-1.0). Conclusions: SARS-CoV-2 is associated with higher odds of insulin treatment but not with higher A1c. Vaccination may be protective.

Reproducibility of Glycemic Measures Among Dysglycemic Youth and Adults in the RISE Study.

AIMS: Previous work found poor reproducibility for measures of glycemia in individuals at risk for dysglycemia. Differences between youth and adults have not been assessed. Using youth and adults in the Restoring Insulin Secretion Study, we tested variability and classification concordance for hemoglobin A1C (HbA1c), fasting and 2-hour glucose from oral glucose tolerance tests (OGTTs). METHODS: HbA1c and glucose on repeated samples obtained ∼6 weeks apart were compared in 66 youth (mean age 14.2 years) and 354 adults (52.7 years). Changes, coefficient of variation (CV), and concordance of diagnostic categories between the 2 visits were compared. RESULTS: Mean difference between the 2 visits in HbA1c was higher in youth than adults (P < .001), while fasting glucose was similar and 2-hour glucose was lower in youth (P = .051). CV was smallest for HbA1c compared to fasting and 2-hour glucose. For HbA1c, youth had higher CV (P < .001); whereas CV for 2-hour glucose was lower for youth (P = .041). Classification concordance by HbA1c was lower in youth (P = .004). Using OGTT or HbA1c for classification, intervisit variability produced discordant classification in 20% of youth and 28% of adults. Using both fasting glucose and HbA1c, intervisit variability reduced discordant classification to 16% of adults while not improving classification in youth. CONCLUSIONS: Poor reproducibility and lack of classification concordance highlight the limitations of one-time testing, with important implications for assessing eligibility in clinical trials. Consideration should be given to using more than a single parameter for screening and diagnosis, especially when classification category is important.

Assessment of circulating insulin using liquid chromatography-mass spectrometry during insulin glargine treatment in type 2 diabetes: Implications for estimating insulin sensitivity and ß-cell function.

AIM: To determine the potential impact of the cross-reactivity of insulin glargine U-100 and its metabolites on insulin sensitivity and ß-cell measures in people with type 2 diabetes. MATERIALS AND METHODS: Using liquid chromatography-mass spectrometry (LC-MS), we measured concentrations of endogenous insulin, glargine and its two metabolites (M1 and M2) in fasting and oral glucose tolerance test-stimulated plasma from 19 participants and fasting specimens from another 97 participants 12 months after randomization to receive the insulin glargine. The last dose of glargine was administered before 10:00 PM the night before testing. Insulin was also measured on these specimens using an immunoassay. We used fasting specimens to calculate insulin sensitivity (Homeostatic Model Assessment 2 [HOMA2]-S%; QUICKI index; PREDIM index) and ß-cell function (HOMA2-B%). Using specimens following glucose ingestion, we calculated insulin sensitivity (Matsuda ISI[comp] index) and ß-cell response (insulinogenic index [IGI], and total incremental insulin response [iAUC] insulin/glucose). RESULTS: In plasma, glargine was metabolized to form the M1 and M2 metabolites that were quantifiable by LC-MS; however, the analogue and its metabolites cross-reacted by less than 100% in the insulin immunoassay. This incomplete cross-reactivity resulted in a systematic bias of fasting-based measures. By contrast, because M1 and M2 did not change following glucose ingestion, a bias was not observed for IGI and iAUC insulin/glucose. CONCLUSIONS: Despite glargine metabolites being detected in the insulin immunoassay, dynamic insulin responses can be used to assess ß-cell responsiveness. However, given the cross-reactivity of the glargine metabolites in the insulin immunoassay, fasting-based measures of insulin sensitivity and ß-cell function are biased.