First-phase Insulin Response Research Articles

278-LB: The Effect of Combining Very-Low-Calorie Diet with Semaglutide on Beta-Cell Function in Individuals with Type 2 Diabetes

Type 2 diabetes (T2D) is characterised by the loss of the first phase response of insulin-producing pancreatic beta cells. Recently, Very-low calorie diets (VLCD - defined as less than 800 kilocalories per day) have been shown to restore this first phase response to induce remission of T2D, while Glucagon-like peptide-1 agonists also improve the first phase response by enhancing postprandial insulin secretion. Here, we present interim results of an investigation exploring the effect of combining these two interventions on beta cell function, in individuals with T2D. Eighteen individuals with T2D and body mass index >27kg.m-2 were randomly allocated into 3 groups: i) Semaglutide (S), ii) VLCD (V), and iii) Semaglutide-plus-VLCD (SV). Semaglutide was administered once weekly gradually up titrated to a maximum dose of 1mg and VLCD regime was provided by LighterLife® total meal replacement. Beta cell function was assessed using intravenous glucose tolerance tests (IVGTT) performed at baseline and 12 weeks. First-phase insulin response was calculated as the incremental area under the suprabasal plasma insulin concentration curve during 0-10 minutes of the IVGTT (µU.min.ml-1). Data were analysed using GraphPad Prism 9.5.0 (La Jolla, USA). All groups were equally matched at baseline. Mean weight loss was 6.4, 14.1 and 14.9 kg in S, V and SV, respectively. A significant improvement in first phase response was observed in all groups (S: +398.5; V: +88.4; SV: +547.8 µU.min.ml-1, all p<0.05 vs. baseline). At 12 weeks, first phase response in SV was significantly higher than in V (583.9 vs. 169.2 µU.min.ml-1 respectively, p<0.05). These data suggest that combination of VLCD and Semaglutide results in a significantly greater improvement in first phase response than VLCD alone. This approach could result in a more robust remission of T2D in the longer-term, and may have important implications for the future design of interventions for the clinical management of T2D. Disclosure O. Anyiam: None. B. E. Phillips: None. D. J. Wilkinson: None. K. Smith: None. P. J. Atherton: None. I. R. Idris: None. Funding Medical Research Council Confidence in Concept Scheme

Liraglutide protects β-cells in novel human islet spheroid models of type 1 diabetes

To enable accurate, high-throughput and longer-term studies of the immunopathogenesis of type 1 diabetes (T1D), we established three in-vitro islet-immune injury models by culturing spheroids derived from primary human islets with proinflammatory cytokines, activated peripheral blood mononuclear cells or HLA-A2-restricted preproinsulin-specific cytotoxic T lymphocytes. In all models, β-cell function declined as manifested by increased basal and decreased glucose-stimulated insulin release (GSIS), and decreased intracellular insulin content. Additional hallmarks of T1D progression such as loss of the first-phase insulin response (FFIR), increased proinsulin-to-insulin ratios, HLA-class I expression, and inflammatory cytokine release were also observed. Using these models, we show that liraglutide, a glucagon-like peptide 1 receptor agonist, prevented loss of GSIS under T1D-relevant stress, by preserving the FFIR and decreasing immune cell infiltration and cytokine secretion. Our results corroborate that liraglutide mediates an anti-inflammatory effect that aids in protecting β-cells from the immune-mediated attack that leads to T1D.

Assessing the Pathophysiology of Hyperglycemia in the Diabetes RElated to Acute Pancreatitis and Its Mechanisms Study: From the Type 1 Diabetes in Acute Pancreatitis Consortium.

The metabolic abnormalities that lead to diabetes mellitus (DM) after an episode of acute pancreatitis (AP) have not been extensively studied. This article describes the objectives, hypotheses, and methods of mechanistic studies of glucose metabolism that comprise secondary outcomes of the DREAM (Diabetes RElated to Acute pancreatitis and its Mechanisms) Study. Three months after an index episode of AP, participants without preexisting DM will undergo baseline testing with an oral glucose tolerance test. Participants will be followed longitudinally in three subcohorts with distinct metabolic tests. In the first and largest subcohort, oral glucose tolerance tests will be repeated 12 months after AP and annually to assess changes in β-cell function, insulin secretion, and insulin sensitivity. In the second, mixed meal tolerance tests will be performed at 3 and 12 months, then annually, and following incident DM to assess incretin and pancreatic polypeptide responses. In the third, frequently sampled intravenous glucose tolerance tests will be performed at 3 months and 12 months to assess the first-phase insulin response and more precisely measure β-cell function and insulin sensitivity. The DREAM study will comprehensively assess the metabolic and endocrine changes that precede and lead to the development of DM after AP.

Oral Glucose Tolerance Test Measures of First-phase Insulin Response and Their Predictive Ability for Type 1 Diabetes.

Decreased first-phase insulin response (FPIR) during intravenous glucose tolerance testing (IVGTT) is an early indicator of β-cell dysfunction and predictor of type 1 diabetes (T1D). Assess whether oral glucose tolerance test (OGTT) measures could serve as FPIR alternatives in their ability to predict T1D in autoantibody positive (Aab+) subjects. OGTT and IVGTT were performed within 30 days of each other. Eleven OGTT variables were evaluated for (1) correlation with FPIR and (2) T1D prediction. Type 1 Diabetes TrialNet "Oral Insulin for Prevention of Diabetes in Relatives at Risk for T1D" (TN-07) and Diabetes Prevention Trial-Type 1 Diabetes (DPT-1) studies clinical sites. TN-07 (n = 292; age 9.4 ± 6.1 years) and DPT-1 (n = 194; age 15.1 ± 10.0 years) Aab + relatives of T1D individuals. (1) Correlation coefficients of OGTT measures with FPIR and (2) T1D prediction at 2 years using area under receiver operating characteristic (ROCAUC) curves. Index60 showed the strongest correlation in DPT-1 (r = -0.562) but was weaker in TN-07 (r = -0.378). C-peptide index consistently showed good correlation with FPIR across studies (TN-07, r = 0.583; DPT-1, r = 0.544; P < 0.0001). Index60 and C-peptide index had the highest ROCAUCs for T1D prediction (0.778 vs 0.717 in TN-07 and 0.763 vs 0.721 in DPT-1, respectively; P = NS), followed by FPIR (0.707 in TN-07; 0.628 in DPT-1). C-peptide index was the strongest measure to correlate with FPIR in both studies. Index60 and C-peptide index had the highest predictive accuracy for T1D and were comparable. OGTTs could be considered instead of IVGTTs for subject stratification in T1D prevention trials.

Could Dietary Modification Independent of Energy Balance Influence the Underlying Pathophysiology of Type 2 Diabetes? Implications for Type 2 Diabetes Remission.

High-quality clinical trial data demonstrate that remission is possible for people living with type 2 diabetes (T2D) if they lose a large amount of weight (≥ 10 kg). Durable remission appears predicated on the long-term maintenance of weight loss. Unfortunately, long-term follow-up data from lifestyle-based weight loss programmes show that, on average, most people regain at least some of the weight lost. In addition, restoration of a diminished first-phase insulin response also appears necessary for durable remission, and this becomes less likely as T2D progresses. A pragmatic approach to enhance the effects of weight loss on durable remission is to consider whether dietary components could help control blood glucose, independent of caloric balance. This manuscript reviews current evidence on weight-neutral effects of diet on blood glucose, including high-protein, low-carbohydrate, high-fibre and plant-based diets, with a particular focus on the effect of nutrition on the underlying pathophysiology of T2D, including the first-phase insulin response. The importance of mechanistic data in enhancing our understanding of dietary strategies in T2D remission is described, and suggestions are made for future advances in remission research.

Oral Glucose Tolerance Test-based Measures of Insulin Secretory Response in Pregnancy.

Oral glucose tolerance test (OGTT)-based measures of insulin secretory response have not been validated in pregnancy. In a secondary analysis of a longitudinal study, participants were studied prepregnancy (n = 40), in early pregnancy (n = 36; 12-14 weeks' gestation), and in late pregnancy (n = 36; 34-36 weeks' gestation). Participants underwent an OGTT, an intravenous glucose tolerance test (IVGTT), and a hyperinsulinemic-euglycemic clamp at each timepoint. We calculated homeostatic model assessment of beta-cell function (HOMA-2B), insulinogenic index (IGI), corrected insulin response (CIR), ratio of the area under the insulin curve and the area under the glucose curve (AUCins/AUCglu), and Stumvoll first-phase estimate (Stumvoll) from OGTT insulin and glucose levels. We used Pearson correlation to compare measures from OGTT and IVGTT. We used mixed effects models to examine longitudinal changes in insulin secretory response. Stumvoll was the only OGTT-based measure that was significantly correlated with first-phase insulin response prior to and across gestation (prepregnancy: r = 0.44, P = 0.01; early pregnancy: r = 0.67, P = 0.0001; late pregnancy: r = 0.67, P = 0.0001). In early and late pregnancy, AUCins/AUCglu had the strongest correlation with first-phase insulin response (early pregnancy: r = 0.79, P < 0.0001; late pregnancy: r = 0.69, P < 0.0001) but was not significantly correlated prepregnancy. IGI and CIR were significantly correlated with first-phase insulin response prepregnancy (IGI: r = 0.50, P = 0.005; CIR r = 0.47, P = 0.008) and in late pregnancy (IGI: r = 0.68, P = 0.0001; CIR r = 0.57, P = 0.002) but not in early pregnancy. HOMA-2B was the weakest correlate of first-phase insulin response. Stumvoll and AUCins/AUCglu recapitulated the longitudinal changes in insulin secretory response observed by IVGTT. Stumvoll and AUCins/AUCglu are valid OGTT-based insulin secretory response measures for pregnancy studies.

Heterogeneity of beta-cell function in subjects with multiple islet autoantibodies in the TEDDY family prevention study - TEFA

BackgroundIndividuals with multiple islet autoantibodies are at increased risk for clinical type 1 diabetes and may proceed gradually from stage to stage complicating the recruitment to secondary prevention studies. We evaluated multiple islet autoantibody positive subjects before randomisation for a clinical trial 1 month apart for beta-cell function, glucose metabolism and continuous glucose monitoring (CGM). We hypothesized that the number and type of islet autoantibodies in combination with different measures of glucose metabolism including fasting glucose, HbA1c, oral glucose tolerance test (OGTT), intra venous glucose tolerance test (IvGTT) and CGM allows for more precise staging of autoimmune type 1 diabetes than the number of islet autoantibodies alone.MethodsSubjects (n = 57) at 2–50 years of age, positive for two or more islet autoantibodies were assessed by fasting plasma insulin, glucose, HbA1c as well as First Phase Insulin Response (FPIR) in IvGTT, followed 1 month later by OGTT, and 1 week of CGM (n = 24).ResultsAutoantibodies against GAD65 (GADA; n = 52), ZnT8 (ZnT8A; n = 40), IA-2 (IA-2A; n = 38) and insulin (IAA; n = 28) were present in 9 different combinations of 2–4 autoantibodies. Fasting glucose and HbA1c did not differ between the two visits. The estimate of the linear relationship between log2-transformed FPIR as the outcome and log2-transformed area under the OGTT glucose curve (AUC) as the predictor, adjusting for age and sex was − 1.88 (− 2.71, − 1.05) p = 3.49 × 10–5. The direction of the estimates for all glucose metabolism measures was positive except for FPIR, which was negative. FPIR was associated with higher blood glucose. Both the median and the spread of the CGM glucose data were significantly associated with higher glucose values based on OGTT, higher HbA1c, and lower FPIR. There was no association between glucose metabolism, autoantibody number and type except that there was an indication that the presence of at least one of ZnT8(Q/R/W) A was associated with a lower log2-transformed FPIR (− 0.80 (− 1.58, − 0.02), p = 0.046).ConclusionsThe sole use of two or more islet autoantibodies as inclusion criterion for Stage 1 diabetes in prevention trials is unsatisfactory. Staging type 1 diabetes needs to take the heterogeneity in beta-cell function and glucose metabolism into account.Trial registrationClinicalTrials.gov identifier: NCT02605148, November 16, 2015

Long-Term Follow-up of β-Transfusion-Dependent Thalassemia (TDT) Normoglycemic Patients with Reduced Insulin Secretion to Oral Glucose Tolerance Test (OGTT): A Pilot Study.

ObjectiveTo study the endocrine pancreas’ function in transfusion-dependent β-thalassemia (β-TDT) patients with a normal glucose tolerance test (NGT) and hypoinsulinemia. In addition, the prospective long–term follow-up using an annual oral glucose tolerance test (OGTT) to detect any abnormality of glucose metabolism.Patients and methodsSeven β-TDT patients (mean age 22.4 ± 4.2 years) with NGT and inadequate insulin response (hypoinsulinemia) to OGTT were referred for a second opinion to an Italian Centre.ResultsThe first-phase insulin response (FPIR), expressed as the sum of 1 and 3 minutes insulin, to intravenous glucose tolerance test (IVGTT), was between the 1st and 3rd percentile in two patients and between the 3rd and 10th percentile in five. The results were not associated with β-cell autoimmunity. After 43 ± 26 months (range 11 – 80 months) of follow-up, two patients developed impaired glucose tolerance (IGT), three both IGT and impaired fasting glucose (IFG) and two overt diabetes mellitus (DM). Interestingly, the patients who developed DM had, at baseline, the lowest value of the insulinogenic index (IGI: 0.08 and 0.25), defined as the ratio of the increment of plasma insulin to plasma glucose during the first 30 minutes after OGTT. Moreover, a significant correlation was found between the IGI at baseline and at follow-up in the patients who developed IGT with or without IFG (R= 0.927; P: 0.023). A significant reduction of Matsuda insulin sensitivity index (ISIM) and Insulin Secretion-Sensitivity Index-2 (ISSI-2) was documented in the study cohort at the diagnosis of IFG, IGT, and DM. There was a significant inverse correlation between ISSI-2 and area under the curve plasma glucose (AUC-PG).ConclusionsThese data demonstrated, for the first time, progressive deterioration in glucose homeostasis in β-TDT subjects with NGT and hypoinsulinemia and that the ISSI-2 index may be a valuable parameter to identify patients at high risk for developing glucose dysregulation.

Pancreatic islet reserve in type 1 diabetes.

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by pancreatic islet βcellloss and dysfunction resulting in insulin deficiency and hyperglycemia. During a presymptomatic phase of established β cell autoimmunity, βcellloss may first be evident through assessment of βcellsecretory capacity, a measure of functional βcellmass. Reduction in pancreatic islet βcellreserve eventually manifests as impaired first-phase insulin response to glucose and abnormal glucose tolerance, which progresses until the functional capacity for βcellsecretion can no longer meet the demand for insulin to control glycemia. A functional βcellmass of ∼25% of normal may be required to avoid symptomatic T1D but is already associated with dysregulated glucagon secretion. With symptomatic T1D, stimulated C-peptide levels >0.60 ng/mL (0.200 pmol/mL) indicate the presence of clinically meaningful residual βcellfunction for contributing to glycemic control, although even higher residual C-peptide appears necessary for evidencing glucose-dependent islet β and α cell function that may contribute to maintaining (near)normal glycemia. βcellreplacement by islet transplantation can restore a physiologic reserve capacity for insulin secretion, confirming thresholds for functional βcellmass required for independence from insulin therapy.

Beta cell function in participants with single or multiple islet autoantibodies at baseline in the TEDDY Family Prevention Study: TEFA.

AimThe aim of the present study was to assess beta cell function based on an oral glucose tolerance test (OGTT) in participants with single islet autoantibody or an intravenous glucose tolerance test (IvGTT) in participants with multiple islet autoantibodies.Materials and methodsHealthy participants in Sweden and Finland, between 2 and 49.99 years of age previously identified as positive for a single (n = 30) autoantibody to either insulin, glutamic acid decarboxylase, islet antigen‐2, zinc transporter 8 or islet cell antibodies or multiple autoantibodies (n = 46), were included. Participants positive for a single autoantibody underwent a 6‐point OGTT while participants positive for multiple autoantibodies underwent an IvGTT. Glucose, insulin and C‐peptide were measured from OGTT and IvGTT samples.ResultsAll participants positive for a single autoantibody had a normal glucose tolerance test with 120 minutes glucose below 7.70 mmol/L and HbA1c values within the normal range (<42 mmol/mol). Insulin responses to the glucose challenge on OGTT ranged between 13.0 and 143 mIU/L after 120 minutes with C‐peptide values between 0.74 and 4.60 nmol/L. In Swedish participants, the first‐phase insulin response (FPIR) on IvGTT was lower in those positive for three or more autoantibodies (n = 13; median 83.0 mIU/L; range 20.0‐343) compared to those with two autoantibodies (n = 15; median 146 mIU/L; range 19.0‐545; P = .0330).ConclusionParticipants positive for a single autoantibody appeared to have a normal beta cell function. Participants positive for three or more autoantibodies had a lower FPIR as compared to participants with two autoantibodies, supporting the view that their beta cell function had deteriorated.

1618-P: Insulin Secretion Variability According to the Specific Type 1 Diabetes (T1D) Risk Predictor

The risk for T1D, a major criterion for entry into disease prevention trials, can be assessed in various ways, but usually includes autoantibody (Ab) and/or metabolic measures. Given inherent variations in these biomarkers, it is possible that informative characteristics differ between populations selected by different risk measures. Thus, we assessed whether indices of insulin secretion [C-pep; first phase insulin response (FPIR)] vary between groups defined by distinctive risk measures. We used data from Diabetes Prevention Trial-Type 1 (DPT-1) participants, all being ICA positive subjects with or without biochemical Ab (bAb) positivity (GADA, IA-2A, mIAA). C-pep and FPIR values from baseline oral and intravenous glucose tolerance tests were compared between those who had 2-3 bAbs (≥2bAb) and those who had 0-1 bAb plus Index60≥0.40 (≤1bAb+Ind60). Index60 is a composite C-pep and glucose measure. These groups were chosen so that T1D risk would be similar (50% 5-year risk for both, log rank p=0.95). Ages (mean±SD) for ≥2bAb (n=289) and ≤1bAb+Ind60 (n=175) were 12.8±8.2 and 13.3±9.6 yrs, respectively (p=0.53). BMI Z-score was greater for ≥2bAb (0.42±1.12 vs. 0.15±1.09, p=0.01). C-pep levels were consistently higher for ≥2bAb than ≤1bAb+Ind60 [30-0 minute C-pep: 2.73±1.58 vs. 2.04±1.12 ng/mL, p&amp;lt;0.0001; area under the curve (AUC) C-pep: 3.70±1.55 vs. 3.27±1.12 ng/ml, p=0.013; AUC C-pep/AUC glucose: 0.030±0.013 vs. 0.025±0.007 (ng/ml)/(mg/dl), p&amp;lt;0.001]. FPIR was also higher for ≥2bAb (122.0±87.3 vs. 96.2±47.1 µU/ml, p&amp;lt;0.01). All comparisons remained significant with adjustments for age and BMI Z-score. Of those with ≤1bAb+Ind60, 0 bAb did not differ from 1 bAb for C-pep indices or FPIR. In conclusion, C-pep and FPIR values can differ appreciably according to the measure that defines risk. This should be considered in choosing risk measures for prevention trials. Disclosure L.M. Jacobsen: None. B.M. Nathan: None. H.M. Ismail: None. M.J. Redondo: None. D. Schatz: None. M.J. Haller: Advisory Panel; Self; SAB Biotherapeutics, Inc. E.K. Sims: None. J.S. Skyler: Advisory Panel; Self; Abvance Therapeutics, ADOCIA, Avotres, Boehringer Ingelheim Pharmaceuticals, Inc., Dance Biopharm Holdings, Inc., Immunomolecular Therapeutics, Intrexon, Oramed Pharmaceuticals, Orgenesis Inc., Sanofi, Tolerion, Inc., Viacyte, Inc. Board Member; Self; Applied Therapeutics, Dexcom, Inc., Intarcia Therapeutics. Consultant; Self; Novo Nordisk A/S. Research Support; Self; Tolerion, Inc. Stock/Shareholder; Self; Applied Therapeutics, Dexcom, Inc., Intarcia Therapeutics. J.P. Palmer: None. K.C. Herold: Consultant; Self; Provention Bio, Inc. J. Sosenko: None.

344-OR: Slowed Metabolic Decline after Oral Insulin (OI) in Relatives at High Risk for Type 1 Diabetes (T1D)

We assessed whether OI slowed metabolic decline after 1 yr of treatment among highest risk relatives who participated in the Diabetes Prevention Trial-Type 1 (DPT1) and TrialNet (TN) T1D prevention trials for OI. As published, with a diagnosis of T1D as the endpoint, both OI trials (7.5 mg/day) were negative overall. However, subgroup analyses suggested efficacy for those at high risk in each trial (DPT1: higher titer of insulin autoantibodies; TN: lower first-phase insulin response). Thus, we assessed whether OI slowed metabolic decline among the OI trial participants at highest risk, defined by DPT1 Risk Scores over a 6.75 threshold (DPTRS; OGTT C-peptide and glucose, age, and BMI), above which T1D risk increases sharply as DPTRS increases. Of 73% in DPT1 and 89% in TN with 1 yr OGTTs, 32% in DPT1 (90/282; age: 8.7±4.8 yrs) and 35% in TN (118/340; age: 6.9±3.3 yrs) were in the highest risk groups (3 yr risks: 56% in DPT-1; 55% in TN). In the analysis, area under curve (AUC) C-peptide increased from baseline to 1 yr in both OI groups (DPT1: p&amp;lt;0.01; TN: p&amp;lt;0.05) but not in the placebo groups, while AUC glucose increased more in the placebo groups (DPT1: p&amp;lt;0.01; TN: p&amp;lt;0.01) than in the OI groups (DPT1: p&amp;lt;0.05; TN: n.s.). Consistent with those changes, in both trials the 1 yr AUC C-peptide/AUC glucose ratio (x100; AUC ratio) was greater in the OI group than in the placebo group [DPT1: 2.86±1.06 vs. 2.42±1.03 (ng/ml)/(mg/dl); TN: 3.06±1.13 vs. 2.57±0.96 (ng/ml)/(mg/dl); p-value&amp;lt;0.05 for each (baseline adjusted)]. For DPT1 and TN combined (no interaction for treatment between trials), the p-value for the AUC ratio difference was &amp;lt;0.001. Of those with DPTRS &amp;lt;6.75 (3 yr risk: 24% for both DPT1 and TN), the AUC ratio did not differ between OI and placebo. In conclusion, when DPTRS was &amp;gt;6.75 metabolic outcomes at 1 yr appeared similarly favorable for OI in the DPT1 and TN trials, suggesting OI slows insulin decline in those at high risk for T1D. Moreover, metabolic measures could be useful endpoints for T1D prevention trials. Disclosure J. Sosenko: None. J.P. Palmer: None. M.J. Haller: Advisory Panel; Self; SAB Biotherapeutics, Inc. J.S. Skyler: Advisory Panel; Self; Abvance Therapeutics, ADOCIA, Avotres, Boehringer Ingelheim Pharmaceuticals, Inc., Dance Biopharm Holdings, Inc., Immunomolecular Therapeutics, Intrexon, Oramed Pharmaceuticals, Orgenesis Inc., Sanofi, Tolerion, Inc., Viacyte, Inc. Board Member; Self; Applied Therapeutics, Dexcom, Inc., Intarcia Therapeutics. Consultant; Self; Novo Nordisk A/S. Research Support; Self; Tolerion, Inc. Stock/Shareholder; Self; Applied Therapeutics, Dexcom, Inc., Intarcia Therapeutics. A. Pugliese: None. D. Schatz: None.

The effect of the ghrelin-receptor agonist capromorelin on glucose metabolism in healthy cats

Somatostatin secretion from islet delta cells is important in maintaining low glycemic variability (GV) by providing negative feedback to beta cells and inhibiting insulin secretion. Capromorelin is a ghrelin-receptor agonist that activates the growth hormone secretagogue receptor on delta cells. We hypothesized that in cats, capromorelin administration will result in decreased GV at the expense of reduced insulin secretion and glucose tolerance. Seven healthy cats were treated with capromorelin from days 1–30. After the first day, fasting blood glucose increased (+13 ± 3 mg/dL, P < 0.0001), insulin decreased (+128 ± 122 ng/dL, P = 0.03), and glucagon was unchanged. Blood glucose was increased throughout an intravenous glucose tolerance test on day 1 with blunting of first-phase insulin response ([FPIR] 4,931 ± 2,597 ng/L/15 min) compared with day −3 (17,437 ± 8,302 ng/L/15 min, P = 0.004). On day 30, FPIR was still blunted (9,993 ± 4,285 ng/L/15 min, P = 0.045), but glucose tolerance returned to baseline. Mean interstitial glucose was increased (+19 ± 6 mg/dL, P = 0.03) on days 2–4 but returned to baseline by days 27–29 (P = 0.3). On days 2–4, GV was increased (SD = 9.7 ± 3.2) compared with baseline (SD = 5.0 ± 1.1, P = 0.02) and returned to baseline on days 27–29 (SD = 6.1 ± 1.1, P = 0.16). In summary, capromorelin caused a decline in insulin secretion and glycemic control and an increase in glucose variability early in the course of treatment, but these effects diminished toward the end of 30 d of treatment.

Time Course of Normalization of Functional β-Cell Capacity in the Diabetes Remission Clinical Trial After Weight Loss in Type 2 Diabetes.

To assess functional β-cell capacity in type 2 diabetes during 2 years of remission induced by dietary weight loss. A Stepped Insulin Secretion Test with Arginine was used to quantify functional β-cell capacity by hyperglycemia and arginine stimulation. Thirty-nine of 57 participants initially achieved remission (HbA1c <6.5% [<48 mmol/mol] and fasting plasma glucose <7 mmol/L on no antidiabetic drug therapy) with a 16.4 ± 7.7 kg weight loss and were followed up with supportive advice on avoidance of weight regain. At 2 years, 20 participants remained in remission in the study. A nondiabetic control (NDC) group, matched for age, sex, and weight after weight loss with the intervention group, was studied once. During remission, median (interquartile range) maximal rate of insulin secretion increased from 581 (480-811) pmol/min/m2 at baseline to 736 (542-998) pmol/min/m2 at 5 months, 942 (565-1,240) pmol/min/m2 at 12 months (P = 0.028 from baseline), and 936 (635-1,435) pmol/min/m2 at 24 months (P = 0.023 from baseline; n = 20 of 39 of those initially in remission). This was comparable to the NDC group (1,016 [857-1,507] pmol/min/m2) by 12 (P = 0.064) and 24 (P = 0.244) months. Median first-phase insulin response increased from baseline to 5 months (42 [4-67] to 107 [59-163] pmol/min/m2; P < 0.0001) and then remained stable at 12 and 24 months (110 [59-201] and 125 [65-166] pmol/min/m2, respectively; P < 0.0001 vs. baseline) but lower than that of the NDC group (250 [226-429] pmol/min/m2; P < 0.0001). A gradual increase in assessed functional β-cell capacity occurred after weight loss, becoming similar to that of NDC group participants by 12 months. This result was unchanged at 2 years with continuing remission of type 2 diabetes.

Hepatic Lipoprotein Export and Remission of Human Type 2 Diabetes after Weight Loss

The role of hepatic lipoprotein metabolism in diet-induced remission of type 2 diabetes is currently unclear. Here, we determined the contributions of hepatic VLDL1-triglyceride production rate and VLDL1-palmitic acid content to changes in intra-pancreatic fat and return of first phase insulin response in a subgroup of the Diabetes Remission Clinical Trial. Liver fat, VLDL1-triglyceride production, and intra-pancreatic fat decreased after weight lossand remained normalized after 24months of remission. First-phase insulin response remained increased only in those maintaining diabetes remission. Compared with those in remission at 24months, individuals who relapsed after initial remission had agreater rise in the content of VLDL1-triglyceride and VLDL1-palmitic acid, re-accumulated intra-pancreatic fat, and lost first-phase response by 24months. Thus, we observed temporal relationships between VLDL1-triglyceride production, hepatic palmitic acid flux, intra-pancreatic fat, and β-cell function. Weight-related disordered fat metabolism appears to drive development and reversal of type 2 diabetes.

Longitudinal Pattern of First-Phase Insulin Response Is Associated With Genetic Variants Outside the Class II HLA Region in Children With Multiple Autoantibodies.

A declining first-phase insulin response (FPIR) is associated with positivity for multiple islet autoantibodies, irrespective of class II HLA DR-DQ genotype. We examined the associations of FPIR with genetic variants outside the HLA DR-DQ region in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study in children with and without multiple autoantibodies. Association between FPIR and class I alleles A*24 and B*39 and eight single nucleotide polymorphisms outside the HLA region were analyzed in 438 children who had one or more FPIR results available after seroconversion. Hierarchical linear mixed models were used to analyze repeated measurements of FPIR. In children with multiple autoantibodies, the change in FPIR over time was significantly different between those with various PTPN2 (rs45450798), FUT2 (rs601338), CTSH (rs3825932), and IKZF4 (rs1701704) genotypes in at least one of the models. In general, children carrying susceptibility alleles for type 1 diabetes experienced a more rapid decline in insulin secretion compared with children without susceptibility alleles. The presence of the class I HLA A*24 allele was also associated with a steeper decline of FPIR over time in children with multiple autoantibodies. Certain genetic variants outside the class II HLA region may have a significant impact on the longitudinal pattern of FPIR.

Augmented insulin secretory response in early pregnancy.

This study aimed to examine changes in the insulin secretory response in early pregnancy, while accounting for changes in insulin sensitivity. This is a secondary analysis of a previously conducted longitudinal physiological study. In 34 women, insulin secretory response (by IVGTT) and insulin sensitivity (by euglycaemic clamp) were assessed prior to pregnancy, in early pregnancy (12-14weeks gestation) and in late pregnancy (34-36weeks gestation). Using mixed-effects models, we compared insulin secretory response and sensitivity in early pregnancy to the same variables prior to pregnancy and in late pregnancy, with adjustment for age, obesity status and gestational diabetes mellitus (GDM). We examined changes in insulin secretory response after adjustment for insulin sensitivity using both multivariate modelling and the disposition index (DI). We explored the relationship between insulin secretory response and circulating hormones. The insulin secretory response increased from prior to pregnancy to early pregnancy (unadjusted mean [SD] first-phase insulin response 465.1 [268.5] to 720 [358.2], p < 0.0001) and from early pregnancy to late pregnancy (to 924 [494.6], p = 0.01). Insulin sensitivity increased from prior to pregnancy to early pregnancy (insulin sensitivity index 0.10 [0.04] to 0.12 [0.05], p = 0.001) and decreased in late pregnancy (to 0.06 [0.03], p < 0.0001). Accounting for changes in insulin sensitivity, using either multivariate modelling or the DI, did not attenuate the early-pregnancy augmentation of insulin secretory response. Leptin was positively associated with insulin secretory response, independent of insulin sensitivity and adiposity (p = 0.004). Adjustment for leptin attenuated the observed augmentation of insulin secretory response in early pregnancy (adjusted mean change 121.5, p = 0.13). The insulin secretory response increases markedly in early pregnancy, prior to and independent of changes in insulin sensitivity. Circulating hormones may mediate this metabolic adaptation. Identifying mediators of this physiological effect could have therapeutic implications for treating hyperglycaemia during and outside of pregnancy.

1343-P: A Comparison of C-Peptide and Glucose Responses between Children and Adolescents Who Progress to Type 1 Diabetes (T1D)

Type 1 diabetes is a heterogeneous disease with differences in β-cell dysfunction and rates of progression. We thus assessed whether there are differences in C-peptide and glucose responses during 2-hour oral (OGTTs) and intravenous (IVGTTs) glucose tolerance tests between children and adolescents at high risk for T1D. Data from the Diabetes Prevention Trial-type 1 (DPT-1) study participants who progressed to T1D was used for the analysis. We compared C-peptide and glucose responses between children (&amp;lt;10.0 years old; 7.1±1.9 years; n=125) and adolescents (10.0 years to &amp;lt;18.0 years old; 12.8±2.2 years; n=94). The risks for T1D were similar between the children and adolescents (mean 3-year T1D estimates from DPT-1 Risk Score: 63% and 56% respectively), as was the time to diagnosis (2.4±2.1 years vs. 2.5±2.2 years, respectively). Adolescents had higher OGTT derived AUC C-peptide levels (3.8±1.5 ng/ml vs. 1.9±1.4 ng/ml; p&amp;lt;0.001 with BMIZ adjustment), whereas their AUC glucose levels were similar to children (138.6±25.1 mg/dl vs. 139.6±22.8 mg/dl). The 0 to 30 minute C-peptide response from baseline OGTTs was significantly higher among adolescents compared to children (2.6±1.6 vs. 2.1±1.2, p=0.004 with BMIZ adjustment). However, C-peptide and glucose changes for each subsequent 30-minute OGTT interval were nearly identical between the children and adolescents. Similar to the 0 to 30 minute C-peptide response, the first-phase insulin response from baseline IVGTTs was higher in adolescents (114.1±74.0 µU/ml vs. 88.6±59.9 µU/ml; p&amp;lt;0.001 with BMIZ adjustment). In conclusion, the findings showed that despite a lower early insulin response in children, OGTT glucose levels were not higher. This suggests increased insulin sensitivity. The findings also showed that despite the lower early insulin response, the time to diagnosis did not differ. Other aspects of insulin responsiveness, and perhaps sensitivity, appear to also determine the progression rate to T1D. Disclosure H.M. Ismail: None. B.M. Nathan: None. J.P. Palmer: None. L. DiMeglio: Research Support; Self; Amgen Inc., Caladrius Biosciences, Inc., Janssen Research &amp; Development, Medtronic, Sanofi. Other Relationship; Self; Dexcom, Inc. J.M. Sosenko: None. Funding National Institutes of Health

Postprandial Reactive Hypoglycemia.

Reactive hypoglycemia (RH) is the condition of postprandially hypoglycemia occurring 2-5 hours after food intake. RH is clinically seen in three different forms as follows: idiopathic RH (at 180 min), alimentary (within 120 min), and late RH (at 240–300 min). When the first-phase insulin response decreases, firstly, blood glucose starts to rise after the meal. This leads to late but excessive secretion of the second-phase insulin secretion. Thus, late reactive hypoglycemia occurs. Elevated insulin levels also cause down-regulation of the insulin post-receptor on the muscle and fat cells, thus decreasing insulin sensitivity. The cause of the increase in insulin sensitivity in IRH at 3 h is not completely clear. However, there is a decrease in insulin sensitivity in late reactive hypoglycaemia at 4 or 5 hours. Thus, patients with hypoglycemia at 4 or 5 h who have a family history of diabetes and obesity may be more susceptible to diabetes than patients with hypoglycemia at 3 h. We believe that some cases with normal glucose tolerance in OGTT should be considered as prediabetes at <55 or 60 mg/dl after 4-5 hours after OGTT. Metformin and AGI therapy may be recommended if there is late RH with IFG. Also Metformin, AGİ, TZD, DPP-IVInhibitors, GLP1RA therapy may be recommended if there is late RH with IGT. As a result, postprandial RH (<55 or 60 mg/dl), especially after 4 hours may predict diabetes. Therefore, people with RH along with weight gain and with diabetes history in the family will benefit from a lifestyle modification as well as the appropriate antidiabetic approach in the prevention of diabetes.

Ventilation inhomogeneity is associated with OGTT-derived insulin secretory defects in cystic fibrosis.

Progressive deterioration of β-cell function is the main mechanism underlying diabetes in cystic fibrosis (CF). Diabetes negatively impacts the clinical status of CF patients years before its onset. We aimed to evaluate if OGTT-derived indices of β-cell function are associated with early markers of lung disease. We carried out a cross-sectional study on 80 CF patients who performed OGTT, spirometry, and nitrogen-multiple breath washout test. β-cell glucose sensitivity and the insulinogenic indices were used as markers of β-cell function and first-phase insulin response to glucose stimulus. We used sex- and age-adjusted multiple linear regression models to estimate the association between OGTT-derived indices and lung function measures. An increment of β-cell glucose sensitivity equal to its interquartile range was associated with an increase in ppFEV1 of 7.6 points (95%CI: 0.8; 14.4) as well as with a decrease in LCI of -1.96 units (95%CI: -3.40; -0.51) and in Scond of -0.016 L-1 (95%CI: -0.026; -0.007). The corresponding figures for insulinogenic index were: 8.6 (95%CI: 3.4; 13.9) for ppFEV1 , -2.03 (95%CI: -3.13; -0.94) for LCI, and -0.014 L-1 (95%CI: -0.021; -0.071) for Scond . When adjusting also for 2-h plasma glucose, both β-cell glucose sensitivity and insulinogenic index remained inversely associated with Scond . Deterioration of β-cell function is related to early lung disease in young patients with mild to normal pulmonary function. This relationship is independent from hyperglycemia and mainly involves conductive airways.