Acute Insulin Response To Glucose Research Articles

Plasma Proteomic Risk Markers of Incident Type 2 Diabetes Reflect Physiologically Distinct Components of Glucose-Insulin Homeostasis.

Plasma proteins are associated with the risk of incident diabetes in older adults independent of various demographic, lifestyle, and biochemical risk factors. These same proteins are associated with subtle differences in measures of glucose homeostasis earlier in life. Proteins that are associated with lower insulin sensitivity in individuals without diabetes tend to be associated with appropriate compensatory mechanisms, such as a stronger acute insulin response or higher glucose effectiveness. Proteins that are associated with future diabetes risk, but not with insulin insensitivity, tend to be associated with lower glucose effectiveness and/or impaired acute insulin response.

Abstract 13308: Complementary Investigations of Plasma Proteomics Identify Novel Protein Associations With Incident Diabetes and Glucose Metabolism

Introduction: Type 2 diabetes (T2D) is a cardiovascular disease risk equivalent and likely results from broad metabolic changes, which high throughput proteomics have helped to unravel. Prior studies are limited by proteomic coverage, cross sectional design, and lack of physiologic phenotyping. Hypothesis: Complementary proteomic studies of incident T2D and physiologic responses to an intravenous glucose tolerance test (IVGTT) will identify novel proteins with roles in glucose homeostasis and future risk of T2D. Methods: Cardiovascular Health Study (CHS) and HERITAGE study participants without diabetes underwent SomaScan ® profiling of 4,776 plasma proteins. HERITAGE participants underwent IVGTT, from which insulin sensitivity index (S I ), acute insulin response to glucose (AIR G ), and glucose effectiveness (S G ) were derived. We used Cox regression to test protein associations with 18-year incident T2D in CHS, and multivariable linear regression to test protein associations with IVGTT measures in HERITAGE. Results: In CHS (N = 2631, 74 ± 5 years, 62% female, 14% Black), 57 proteins were significantly associated with incident T2D after comprehensive covariate and multiple testing adjustment. Of these, 44, 9, and 8 were associated with S I , AIR G , and S G respectively in HERITAGE (N = 752, 35 ± 14 years, 55% female, 38% Black) (Figure). Notable findings include beta-glucuronidase, which associated with increased T2D risk (HR 1.46 per SD increase in log 2 protein level) and lower S G , suggesting a role in insulin-independent glucose disposal, and thrombospondin-2, which associated with increased T2D risk (HR 1.26 per SD), lower AIR G , and not with S I , indicating that it may be a marker of pancreatic dysfunction. Conclusions: By integrating proteomics from two complementary prospective cohorts using different but related outcomes, we identified 34 novel protein-T2D associations, and characterized their relationship with physiologic axes of glucose metabolism.

Validity and reliability of simple surrogate indexes to evaluate beta-cell function and insulin sensitivity.

Simple surrogate indexes (SSI) to assess beta-cell function, insulin sensitivity (IS) and insulin resistance (IR) are an easy and economic tool used in clinical practice to identify glucose metabolism disturbances. To evaluate the validity and reliability of SSI that estimate beta-cell function, IS and IR using as a reference the parameters obtained from the frequently sampled intravenous glucose tolerance test (FSIVGTT). We included 62 subjects aged 20-45 years, with a normal body mass index and without diabetes or prediabetes. SSI were compared with the acute insulin response to glucose (AIRg), insulin sensitivity index (Si) and disposition index (DI) obtained from the FSIVGTT using the minimal model approach. Half of the participants (n = 31) were randomly selected for a second visit two weeks later to evaluate the reliability of all the variables. HOMA1-%B and HOMA2-%B had a significant correlation with AIRg (Spearman Rho (rs) = 0.33 and 0.37 respectively, p < 0.01). The SSI evaluating IS/IR that showed stronger correlation (rs > 0.50) with Si were fasting insulin, HOMA1-IR, HOMA2-IR, HOMA1-%S, HOMA2-%S, QUICKI, and the McAuley index. The parameters that showed good reliability with an intraclass correlation coefficient (ICC) > 0.75 were AIRg, HOMA1-%S, HOMA2-%S, and QUICKI. Our results suggest that most of the SSI are useful and reliable.

Comparison of insulin sensitivity between healthy neonatal foals and horses using minimal model analysis.

The equine neonate is considered to have impaired glucose tolerance due to delayed maturation of the pancreatic endocrine system. Few studies have investigated insulin sensitivity in newborn foals using dynamic testing methods. The objective of this study was to assess insulin sensitivity by comparing the insulin-modified frequently sampled intravenous glucose tolerance test (I-FSIGTT) between neonatal foals and adult horses. This study was performed on healthy neonatal foals (n = 12), 24 to 60 hours of age, and horses (n = 8), 3 to 14 years of age using dextrose (300 mg/kg IV) and insulin (0.02 IU/kg IV). Insulin sensitivity (SI), acute insulin response to glucose (AIRg), glucose effectiveness (Sg), and disposition index (DI) were calculated using minimal model analysis. Proxy measurements were calculated using fasting insulin and glucose concentrations. Nonparametric statistical methods were used for analysis and reported as median and interquartile range (IQR). SI was significantly higher in foals (18.3 L·min-1· μIU-1 [13.4–28.4]) compared to horses (0.9 L·min-1· μIU-1 [0.5–1.1]); (p < 0.0001). DI was higher in foals (12 × 103 [8 × 103−14 × 103]) compared to horses (4 × 102 [2 × 102−7 × 102]); (p < 0.0001). AIRg and Sg were not different between foals and horses. The modified insulin to glucose ratio (MIRG) was lower in foals (1.72 μIUinsulin2/10·L·mgglucose [1.43–2.68]) compared to horses (3.91 μIU insulin2/10·L·mgglucose [2.57–7.89]); (p = 0.009). The homeostasis model assessment of beta cell function (HOMA-BC%) was higher in horses (78.4% [43–116]) compared to foals (23.2% [17.8–42.2]); (p = 0.0096). Our results suggest that healthy neonatal foals are insulin sensitive in the first days of life, which contradicts current literature regarding the equine neonate. Newborn foals may be more insulin sensitive immediately after birth as an evolutionary adaptation to conserve energy during the transition to extrauterine life.

Racial differences in psychological stress and insulin sensitivity in non-Hispanic Black and White adolescents with overweight/obesity

Introduction: Racial differences in type 2 diabetes risk persist among non-Hispanic Black and non-Hispanic White adolescents with overweight/obesity; however, the role of psychological stress in this disparity is less clear. Purpose: To examine racial differences in the association between psychological stress, insulin sensitivity (Si), acute insulin response to glucose (AIRg), and disposition index (DI) among non-Hispanic Black and non-Hispanic White adolescents with overweight/obesity. Methods: Ninety-six adolescents (60% female; 51% non-Hispanic Black; 16.6 ± 1.8 years of age) with overweight/obesity (BMI percentile ≥ 85th percentile) were included in this analysis. Psychological stress was assessed using the 14-item Perceived Stress Scale. Glucose and insulin data from an intravenous glucose tolerance test was modeled to obtain Si, AIRg, and DI. Multivariable linear regression models were used to examine the association between race, psychological stress and metabolic outcomes (Si, AIRg, and DI). Results: Race was a significant predictor of log-AIRg and log-DI (ps < 0.05) independent of all covariates in the main effect models. Lower Si (pinteraction = 0.014) and DI (pinteraction = 0.012) was also observed among Black adolescents who reported higher stress levels, whereas higher Si and DI was observed among non-Hispanic White adolescents reporting higher stress in the race interaction models. Race however, did not moderate the association between psychological stress and AIRg (p > 0.05), nor was stress associated with Si, AIRg, or DI ("p" "s" > 0.05) across all other models. Conclusions: Psychological stress may play an important and distinct role in shaping racial differences in type 2 diabetes risk among adolescents with overweight/obesity. Additional research is needed to understand the long-term effects of psychological stress on metabolic health among non-Hispanic Black and non-Hispanic White adolescents with overweight/obesity.

Chronic binge alcohol and ovariectomy-mediated impaired insulin responsiveness in SIV-infected female rhesus macaques.

Aging people living with HIV (PLWH), especially postmenopausal women may be at higher risk of comorbidities associated with HIV, antiretroviral therapy (ART), hypogonadism, and at-risk alcohol use. Our studies in simian immunodeficiency virus (SIV)-infected male macaques demonstrated that chronic binge alcohol (CBA) reduced acute insulin response to glucose (AIRG), and at-risk alcohol use decreased HOMA-β in PLWH. The objective of this study was to examine the impact of ovariectomy (OVX) on glucose-insulin dynamics and integrity of pancreatic endocrine function in CBA/SIV-infected female macaques. Female macaques were administered CBA (12-15 g/kg/wk) or isovolumetric water (VEH) intragastrically. Three months after initiation of CBA/VEH administration, all macaques were infected with SIVmac251, and initiated on antiretroviral therapy (ART) 2.5 mo postinfection. After 1 mo of ART, macaques were randomized to OVX or sham surgeries (n = 7 or 8/group), and euthanized 8 mo post-OVX (study endpoint). Frequently sampled intravenous glucose tolerance tests (FSIVGTT) were performed at selected time points. Pancreatic gene expression and islet morphology were determined at study endpoint. There was a main effect of CBA to decrease AIRG at Pre-SIV and study endpoint. There were no statistically significant OVX effects on AIRG (P = 0.06). CBA and OVX decreased the expression of pancreatic markers of insulin docking and release. OVX increased endoplasmic stress markers. CBA but not OVX impaired glucose-insulin expression dynamics in SIV-infected female macaques. Both CBA and OVX altered integrity of pancreatic endocrine function. These findings suggest increased vulnerability of PLWH to overt metabolic dysfunction that may be exacerbated by alcohol use and ovarian hormone loss.

202-LB: Reduced Glucose Effectiveness Exacerbates Impaired Glucose Tolerance in Prediabetic Dogs

The prodromal prediabetic state is characterized by glucose intolerance. Both insulin-dependent (sensitivity, secretion, clearance) and -independent factors (“glucose effectiveness”) contribute to glucose homeostasis. The relative importance of glucose effectiveness is not known. Healthy dogs (n=18) were tested at baseline (BL), after 6 wk on a high-fat diet (HFD), and 2 wk, after a sub-diabetogenic dose of streptozotocin (STZ, 18.5 mg/kg); HFD was continued. We performed intravenous glucose tolerance tests (IVGTTs)at 0, 6, and 8 wks. Minimal model analysis quantified insulin sensitivity (SI), acute insulin response to glucose (AIRg), disposition index (DI, = SI x AIRg), and glucose tolerance (KG). Glucose effectiveness (SG) was measured both by minimal model analysis and directly by multi-step hyperglycemic clamps at basal insulin in a subset of the dogs (n=5). Consumption of HFD induced 7.7±1.0% weight gain (P&amp;lt;0.001) and reduced SI (BL: 3.33±0.35; HFD: 2.01±0.38 x 104 min-1 per µU/ml; P=0.02). HFD elicited an increased AIRg (BL: 596±42; HFD: 1865±476 µU/ml, P=0.03) while maintaining KG (BL: 3.33±0.25; HFD: 3.67±0.33 min-1, P=0.69) as well as β-cell function expressed as DI (BL: 1939±236; HFD: 1882±199, P=0.97). SG was not changed by fat feeding per se (P=0.88). Prediabetes (STZ) conserved fasting glucose, but KG deteriorated (-45% from HFD to STZ) due to sustained insulin resistance with compromised β-cell function (DI decreased by 45±8%, P&amp;lt;0.01). Additionally, minimal model-based SG declined 37±8% from HFD to STZ (0.044±0.003 vs. 0.027±0.003 min-1, P&amp;lt;0.01), a result confirmed by glucose clamps (-30%). Impairments in both insulin-dependent and insulin-independent factors contribute to the glucose intolerance of experimental prediabetes. Rather than compensating for insulin resistance and beta-cell dysfunction, glucose effectiveness also declines, demonstrating that it exacerbates and contributes to glucose intolerance in the canine model of prediabetes. Disclosure C. M. Kolka: Research Support; Self; AstraZeneca. J. Porter: None. M. Ader: None. R. N. Bergman: None. Funding National Institutes of Health (DK27619, DK29867)

Chronic binge alcohol impairs glucose‐insulin dynamics in SIV‐infected female rhesus macaques

Background Antiretroviral therapy (ART) has significantly reduced mortality of people living with HIV (PLWH). Older PLWH, especially post-menopausal women, experience complex interactions of HIV, ART, hormonal status, and lifestyle behaviors such as at-risk alcohol use, increasing the risk of metabolic comorbidities. We have previously shown that chronic binge alcohol (CBA) reduces the acute insulin response to a glucose challenge in SIV-infected male macaques and that at-risk alcohol use decreases HOMA-β (a marker for pancreatic beta cell function) in PLWH. Meanwhile, the role of estrogen in pancreatic health maintenance is not fully understood. The objective of this study was to determine the effect of CBA and ovarian hormone loss, resulting from ovariectomy (OVX), on glucose-insulin dynamics and pancreatic integrity in SIV-infected female rhesus macaques. Hypothesis We hypothesized that chronic binge alcohol and ovariectomy would decrease insulin response to a glucose challenge and impair insulin and glucagon expression in pancreatic islets. Methods 28 adult female macaques were used in the study. CBA or isovolumetric water (VEH) was administered through an intragastric catheter for 30 minutes, 5 days a week, with blood alcohol concentrations reaching 50-60 mM. Three months after initiation of CBA/VEH administration, macaques were infected with SIVMac251 and 2.5 months later initiated on ART. After 1 month of ART, macaques underwent sham surgery or ovariectomy. Using a modified frequently sampled intravenous glucose tolerance test (FSIVGTT), blood glucose and serum insulin values were measured. Glucose and insulin dynamic measures including the acute insulin response to glucose (AIRg), insulin sensitivity (Si), disposition index (DI), and glucose effectiveness (Sg) were determined using minimal model software. Insulin and glucagon expression was determined in formalin-fixed, paraffin-embedded pancreatic tissue collected at study endpoint. Corrected total cell fluorescence for insulin and glucagon were calculated using ImageJ software. To confirm these results, total RNA was isolated from pancreas and mRNA expression of insulin and glucagon determined using quantitative PCR. Results There was a main effect of CBA to decrease AIRg (p=0.02) and increase Si (p=0.01). There were no statistically significant effects of OVX on AIRg (p=0.06) or Si (p=0.4). There were also no statistically significant effects of CBA or OVX on DI or Sg. Neither CBA nor OVX altered the protein or mRNA expression of insulin and glucagon in pancreatic islets. Conclusion CBA decreased the acute endogenous insulin release in response to a glucose challenge without significantly altering basal pancreatic islet expression of insulin and glucagon, while OVX did not significantly alter any of these measures. These results indicate that CBA impairs the immediate release of insulin from beta cell insulin secretory vesicles, and we speculate that CBA dysregulates the metabolic signaling pathway of insulin secretion. Determining mechanisms of pancreatic endocrine dysfunction will inform therapeutic strategies to improve alcohol-mediated impaired glucose insulin dynamics in the context of SIV/HIV.

Two-Year Treatment With Metformin During Puberty Does Not Preserve β-Cell Function in Youth With Obesity.

Youth-onset type 2 diabetes is a disease of pubertal onset, associated with additional burden of pubertal insulin resistance on the β-cell. Evaluate the impact of metformin treatment during puberty, a critical window of cardiometabolic change, on insulin sensitivity (Si) and compensatory β-cell response in youth with obesity. Pediatric academic hospital clinical translational research center. Healthy youth in early puberty [Tanner stage (T) 2-3] with normoglycemia and obesity (n = 44). Double-blinded placebo-control trial of metformin during puberty (until T5). Insulin sensitivity (Si), insulin response [acute insulin response to glucose (AIRg)], and disposition index (DI), estimated from frequently sampled intravenous glucose tolerance testing; body fat (dual X-ray absorptiometry); and other laboratory parameters, collected at baseline, T4, and T5. Placebo-subtracted treatment effect was calculated using linear mixed models. At T5, metformin treatment, adjusting for sex, race, and baseline value, was associated with improved BMI z-score (-0.44 ± 0.16, P = 0.02), percentage body fat (%body fat; -3.4 ± 1.2%, P = 0.06), and waist circumference (-11.3 ± 3.2cm, P = 0.003). There were no significant treatment effects at T5 on Si or secretion: Si (0.85 ± 0.87 × 10-4/min-1/μIU/mL, P = 0.34), AIRg (-259 ± 386 μIU/mL, P = 0.51), or DI (508 ± 802 × 10-4/min-1, P = 0.53). High baseline DI predicted longitudinal decline in DI. Two years of metformin treatment in obese youth during puberty improved BMI and body fat, but not Si or β-cell function. Of note, high DI in early puberty may be predictive of later decline in DI. Further studies are needed to develop strategies for preservation of β-cell function in youth at risk for type 2 diabetes.

Dissociation Between Insulin Resistance and Abnormalities in Lipoprotein Particle Concentrations and Sizes in Normal-Weight Chinese Adults.

Insulin resistance in obesity coincides with abnormalities in lipid profile and lipoprotein subclass distribution and size even before abnormalities in glucose homeostasis manifest. We aimed to assess this relationship in the absence of obesity. Insulin sensitivity (3-h intravenous glucose tolerance test and minimal modeling) and lipoprotein particle concentrations and sizes (proton nuclear magnetic resonance spectroscopy) were evaluated in 15 insulin-resistant and 15 insulin-sensitive lean Asians of Chinese descent with normal glucose tolerance, matched on age, sex, and body mass index. Despite a ~50% lower insulin sensitivity index (Si) in insulin-resistant than in insulin-sensitive subjects, which was accompanied by significantly greater acute insulin response to glucose (AIRg) and fasting insulin concentration but not different fasting glucose concentration, there were no significant differences between groups in the blood lipid profile (p ≥ 0.44) or the lipoprotein subclass concentrations (p ≥ 0.30) and particle sizes (p ≥ 0.43). We conclude that, contrary to observations in subjects with obesity, insulin resistance is not accompanied by unfavorable changes in the plasma lipid profile and lipoprotein particle concentrations and sizes in lean Asians with normal glucose tolerance. Therefore, insulin resistance at the level of glucose metabolism is mechanistically or temporally dissociated from lipid and lipoprotein metabolism.Trial Registration: clinicaltrials.gov, NCT03264001.

The role of family history of diabetes as a predictor of insulin activity in a sample of diverse, normal weight children

AimsThis study aimed to examine the relationship between family history of type 2 diabetes and insulin activity in a diverse sample of normal weight children. MethodsMeasures of fasting insulin, insulin sensitivity and acute insulin response to glucose (AIRg) were obtained from a multiethnic sample of normal weight children ages 7-12 years (n=199). Multiple linear regression was used to determine the effect of family history of type 2 diabetes on the variables of interest. All models were adjusted by age, sex, pubertal status, ethnicity, waist circumference and total grams of carbs. ResultsFamily history of type 2 diabetes was a significant predictor of fasting insulin (p=0.04). There were no significant differences in age, sex, ethnicity, BMI percentile, pubertal stage, or body composition between children with and without a family history of diabetes. ConclusionsFamily history of diabetes is a significant predictor of fasting insulin in a cross-sectional group of children who are normal weight. These results contribute to the further understanding of the relationship between family history and type 2 diabetes risk, which could be utilized to develop earlier detection of dysglycemia and unique disease prevention strategies for at-risk children.

Effect of oral aleurone supplementation on glucose and insulin dynamics of horses in training

Aleurone is known to have positive effects on energy metabolism in pigs and mice. Our aim was to study the effect of oral aleurone supplementation on glucose and insulin dynamics in healthy trained horses in a cross-over training trial. Sixteen Standardbred mares (3-4y) were trained for 2 periods of 8 weeks, fed iso-energetic diets with and without 200 gr/day aleurone. A frequently sampled intravenous glucose tolerance test (FSIGTT) and an oral glucose tolerance test (OGTT) were executed before and after each training period. For the OGTT outcome variables included: Maximumglucose, AUCglucose, Maximuminsulin, AUCinsulin, and Time to peakinsulin; for the FSIGTT: acute insulin response to glucose (AIRg), insulin sensitivity (SI), glucose effectiveness (Sg) and disposition index (DI). Either a paired T-test was applied or a paired Wilcoxon test. Training without aleurone induced significant OGTT variable changes, which were not seen in the FSIGTT. OGTT Maximuminsulin was significantly lower (P=0.005); Time to peakinsulin was higher (P=0.03) and AUCinsulin was lower after training (P=0.001). Training with aleurone decreased AIRg (P=0.03) and increased Sg (P=0.02). When comparing the FSIGTT variables after training with aleurone to those after training without aleurone AIRg was significantly lower in the aleurone fed group (P=0.004). Aleurone has a beneficial effect on glucose and insulin dynamics on top of training in healthy horses. This is attributable to increased tissue glucose uptake capacity. However, more research is needed to elucidate the mode of action of aleurone at the level of the skeletal muscle and the gut.

360-OR: BETA-2 Score Is Highly Correlated with Acute Insulin Response to Intravenous Glucose: An Analysis of the Clinical Islet Transplantation Consortium Trials

Accurate measurement of islet function after clinical islet transplantation (CIT) is challenging. Maximum insulin secretion can be estimated from the acute insulin response to glucose (AIRg) during frequently sampled intravenous glucose tolerance tests (FSIGT). BETA-2, a composite measure derived from a single blood test is practical for routine use. To test the validity of BETA-2, we examined its relationship with AIRg in subjects participating in CIT Consortium trials. 128 C-peptide negative subjects (48.2 ± 10.9 yrs, 38.7% male) underwent 355 FSIGTs prior to and every 6 months after CIT. They received 1-3 islet infusions of &amp;gt;4000 IE/kg. AIRg was derived using the minimal model. BETA-2 was calculated within 90 days of FSIGT (&amp;gt;75% were within 1 day). BETA-2 is plotted against log (AIRg+1) with a loess smoothing curve. BETA-2 is linearly related to log(AIRg) particularly when AIRg &amp;gt; ∼ 6.5 (ie log(AIRg +1) &amp;gt; 2). A linear regression, after raising AIRgs below 6.5 to 6.5, shows an intercept close to 0, a slope of 8.71, and an R2 of 0.69. Limiting the linear regression to test pairs done on successive days had no significant or meaningful effect on this relation. BETA-2 is highly correlated with AIRg, which is related to maximum insulin release and can be used as a validated measure to estimate beta cell mass in CIT. Disclosure P.A. Senior: None. M.R. Rickels: Consultant; Self; Semma Therapeutics, Inc. Research Support; Self; Xeris Pharmaceuticals, Inc. T. Eggerman: None. L. Bayman: None. J. Qidwai: None. R. Alejandro: None. J.F. Markmann: None. L.G. Hunsicker: Advisory Panel; Self; Allergan plc., Bristol-Myers Squibb.

358-OR: ß-Cell Function and Insulin Sensitivity with Islet Alone and Islet-after-Kidney Transplantation for Type 1 Diabetes in the Clinical Islet Transplantation (CIT) Consortium

Phase 3 studies of islet transplant alone (ITA) and islet-after-kidney (IAK) transplantation in type 1 diabetes were completed by the CIT Consortium using the same procedures for islet manufacturing and induction immunosuppression but differing in maintenance immunosuppression. Both studies met their criteria for safety and efficacy over 2 and 3 year planned follow-up, respectively. The insulin sensitivity index, SI, was derived from an insulin-modified frequently sampled intravenous glucose tolerance (FSIGT) test using the minimal model approach before (repeated annually) and after islet transplantation, with post-transplant tests also used to assess β-cell function from the acute insulin response to glucose (AIRg) and the disposition index (DI = AIRg SI). Seventy subjects (48 ITA and 22 IAK) completed 79 tests before and 203 tests between 75 days and 3 years after islet transplantation. SI increased post-transplant in both groups and displayed an apparent hyperbolic relationship with post-transplant AIRg. Post-transplant SI was greater in ITA vs. IAK (P &amp;lt; 0.001). Log-transformed AIRg and SI indicate that SI is ∼24% lower at any given AIRg for IAK than ITA. Neither AIRg nor DI was significantly different between ITA and IAK post-transplant. Log-transformed AIRg and DI demonstrate significant prediction of islet graft failure (defined by mixed-meal tolerance test stimulated C-peptide &amp;lt; 0.3 ng/mL) such that each log increase of AIRg and DI reduces the hazard of islet graft failure by 45% and 42%, respectively. These results indicate that while insulin sensitivity improved after islet transplantation, post-transplant measures of β-cell function may better predict islet graft survival. Whether the differences in maintenance immunosuppression (low-dose tacrolimus and sirolimus, ITA; tacrolimus and mycophenolic acid, IAK) may explain the greater insulin sensitivity in ITA vs. IAK requires further study. Disclosure M.R. Rickels: Consultant; Self; Semma Therapeutics, Inc. Research Support; Self; Xeris Pharmaceuticals, Inc. T. Eggerman: None. L. Bayman: None. J. Qidwai: None. J. Naji: None. H.T. Nguyen: None. R. Alejandro: None. M. Bellin: Research Support; Self; Dexcom, Inc., Viacyte, Inc. Other Relationship; Self; Insulet Corporation. P. Senior: Research Support; Self; Allergan, Novo Nordisk. L.G. Hunsicker: Advisory Panel; Self; Allergan plc., Bristol-Myers Squibb. Funding National Institutes of Health; JDRF (1-SRA-2019-728-A-N)

1266-P: Puberty Is Associated with a Rising HbA1c, Even in Healthy Normal Weight Youth

Objective: ADA definitions of prediabetes are applied to children, yet little is known about the impact of the transient insulin resistance of puberty on glycemia. We aimed to evaluate the longitudinal trajectory of hemoglobin A1c (HbA1c) in youth with normal weight and with obesity as they progressed through puberty. Methods: Youth with normal weight (n=47, 49% female) or obesity (n=37, 62% female) of mixed race/ethnicity (Non-Hispanic White 34%, Hispanic 45%, Non-Hispanic Black 13%) entered the study in Tanner stage 2-3 (T2-3) and were followed until T5. Study visits were done at T2-3, T4, and T5 and included an IV glucose tolerance test, DXA, and fasting laboratory studies. HbA1c was measured by high-performance liquid chromatography and insulin sensitivity (Si), acute insulin response to glucose (AIRg), and disposition index (DI) were calculated. Group differences in HbA1c over time and time-dependent predictors of HbA1c were evaluated by mixed models, with and without adjusting for sex, race/ethnicity, and DXA %Fat. Results: Mean HbA1c was higher in youth with obesity (5.30±0.08%) vs. normal weight (5.10±0.06%, p=0.04) at baseline and each subsequent time point; differences were attenuated by adjusting for %Fat. HbA1c increased from T2/3 to T5 in the whole cohort (0.16±0.05%, p=0.004), and in youth with obesity (+0.18±0.08%, p=0.08), or normal weight (+0.14±0.05%, p=0.02); findings were similar after adjusting for sex, race/ethnicity, and %Fat. In a multivariate model adjusted for sex and race/ethnicity, HbA1c was associated with leptin (β=0.005, p=0.01) and adiponectin (β=-0.01p=0.02); these associations are similar after adjusting for %Fat. HbA1c was not associated with Si, AIRg or DI. Conclusions: Obesity is associated with higher HbA1c than normal weight during puberty. However, HbA1c increased during puberty, independent of body weight and composition. This increase in HbA1c is associated with changes in adipokines, but not with typical predictors of progression to diabetes (Si, DI). Disclosure M.M. Kelsey: Other Relationship; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Janssen Pharmaceuticals, Inc., Merck Sharp &amp; Dohme Corp. A.M. Hilkin: None. C. Severn: None. L. Pyle: None. K.J. Nadeau: None. P. Zeitler: Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly and Company, Merck &amp; Co., Inc. Funding American Diabetes Association (1-11-JF-23 to M.M.K.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (HD057022-04); University of Colorado Center for Women’s Health Research; Children’s Hospital Colorado Research Institute; National Institute for Diabetes and Digestive and Kidney Diseases (DK048520-13); National Center for Advancing Translational Sciences (UL1TR001082)

SUN-621 Body Weight and Body Composition in Patients with Chronic Pancreatitis Are Associated with Islet Function After Total Pancreatectomy and Islet Cell Transplantation

Background: Total pancreatectomy with islet autotransplant (TPIAT) is done in patients with chronic pancreatitis to treat intractable pain. In TPIAT, islets are isolated after pancreatectomy and infused into the liver via the portal vein to mitigate post-operative diabetes. Outcomes vary, with ≥60% needing exogenous insulin supplementation to maintain normoglycemia. The current study’s aim was to determine if pre-surgical body composition is associated with islet function and insulin sensitivity after TPIAT. Methods: We characterized body weight and composition as related to insulin sensitivity and dependence and diabetes outcome in 88 adults who underwent TPIAT for chronic pancreatitis at the University of Minnesota. At baseline, 12 and 18 months after TPIAT, insulin independence was assessed; metabolic testing used mixed meal tolerance testing and frequent sample intravenous glucose tolerance testing. Body composition was measured by Dual X-ray absorptiometry (DXA). Statistical analyses used linear and logistic regression. Results: At baseline, mean age was 39.9 (SD 11.1) years. 9.1% were underweight (BMI<18.5 kg/m2), 45.5% normal weight (BMI=18.5–24.9), 22.7% overweight (BMI=25–29.9) and 22.7% obese (BMI≥30). Islet equivalent per kg did not differ between body weight categories (p=0.17). Overweight/obese patients had higher peak and AUC c-peptide and lower insulin sensitivity index, as expected. Compared to baseline, android to gynoid fat ratio was lower at 12 (0.80 vs 0.88; p=0.012) and 18 months (0.81 vs 0.88; p=0.041), and lean mass was lower at 18 months (38848 vs 42338 kg; p=0.029). Baseline body weight was positively associated with acute insulin response to glucose (AIRg) at 12 months (effect size 38.5, SE 17.1 mU/L/min; p=0.029) and 18 months (38.3, SE 18.5 mU/L/min; p=0.045), while baseline lean mass was inversely associated with AIRg at 12 (p=0.01) and 18 months (p=0.033). Baseline body weight was positively associated, and fat mass inversely associated with disposition index (Di; islets’ ability to secrete insulin normalized to insulin resistance) at 18 months (p=0.019 for both).Percent body fat and percent gynoid fat predicted Sg (glucose effectiveness index, i.e., ability of glucose to promote its own disposal and inhibit hepatic glucose production absent an incremental insulin effect) at 18 months (p=0.042 and p=0.019, respectively). Insulin independence at 12 and 18 months was not significantly associated with baseline body weight or body composition. Conclusions: Overweight/obesity is common in patients with chronic pancreatitis. After TPIAT, patients had lower muscle mass and A/G ratio. Preoperative body weight and composition were associated with islet function but not insulin independence after TPIAT surgery.

Trafficking of nonesterified fatty acids in insulin resistance and relationship to dysglycemia.

In adipose, insulin functions to suppress intracellular lipolysis and secretion of nonesterified fatty acid (NEFA) into plasma. We applied glucose and NEFA minimal models (MM) following a frequently sampled intravenous glucose tolerance test (FSIVGTT) to assess glucose-specific and NEFA-specific insulin resistance. We used total NEFA and individual fatty acids in the NEFA MM, comparing the model parameters in metabolic syndrome (MetSyn) subjects (n = 52) with optimally healthy controls (OptHC; n = 14). Results are reported as mean difference (95% confidence interval). Using the glucose MM, MetSyn subjects had lower [-73% (-82, -57)] sensitivity to insulin (Si) and higher [138% (44, 293)] acute insulin response to glucose (AIRg). Using the NEFA MM, MetSyn subjects had lower [-24% (-35, -13)] percent suppression, higher [32% (15, 52)] threshold glucose (gs), and a higher [81% (12, 192)] affinity constant altering NEFA secretion (ϕ). Comparing fatty acids, percent suppression was lower in myristic acid (MA) than in all other fatty acids, and the stearic acid (SA) response was so unique that it did not fit the NEFA MM. MA and SA percent of total were increased at 50 min after glucose injection, whereas oleic acid (OA) and palmitic acid (PA) were decreased (P < 0.05). We conclude that the NEFA MM, as well as the response of individual NEFA fatty acids after a FSIVGTT, differ between OptHC and MetSyn subjects and that the NEFA MM parameters differ between individual fatty acids.

Conjugated Estrogens and Bazedoxifene Improve β Cell Function in Obese Menopausal Women.

ContextStudies suggest that menopausal hormone therapy (MHT) prevents type 2 diabetes (T2D). The combination of conjugated estrogens (CE) with the selective estrogen receptor modulator bazedoxifene (BZA) is an MHT that improves obesity and T2D in preclinical models of menopausal metabolic syndrome. The effect of CE/BZA on adiposity and glucose homeostasis in obese postmenopausal women is unknown.ObjectiveTo investigate the effect of CE/BZA on body composition, glucose homeostasis, and markers of inflammation in obese postmenopausal women.Research Design, Intervention, and ParticipantsRandomized, double-blind, placebo-controlled pilot trial of 12 obese menopausal women assigned to 12-week treatment with CE 0.45 mg/BZA 20 mg (n = 7) or placebo (n = 5). At baseline and after 12 weeks, we assessed body composition (dual-energy X-ray absorptiometry), glucose homeostasis (IV glucose tolerance test), and inflammation biomarkers.ResultsWomen treated with CE/BZA exhibited increased β cell function using homeostatic model assessment-B [median (interquartile range) CE/BZA vs placebo: 18.5 (−0.9 to 320.6) μU/mM vs −25.5 (−39.9 to −0.1) μU/mM; P = 0.045], and decreased basal glucose concentrations (Gb) [−5.2 (−9.2 to −1.7) mg/dL vs 2.7 (0.9 to 4.9) mg/dL; P = 0.029]. Insulin sensitivity was higher in the placebo arm [1.35 (1.12 to 1.82) (μU/mL) min−1 vs −0.24 (−1.50 to 0.19) (μU/mL) min−1; P = 0.029]. No changes between treatment groups were observed for the acute insulin response to glucose (AIRg), the disposition index (DI), body composition, and inflammatory biomarkers.ConclusionsA 12-week treatment of obese postmenopausal women with CEs/BZA improves fasting β cell function and glucose concentrations without change in AIRg, HOMA-IR, DI, body composition, or markers of inflammation.

Effect Of Breaking-up Sedentary Activity On Metabolic Flexibility And Glycemia In Free-living Overweight/obese Adults

PURPOSE: Sedentary behavior (SB) triggers an inability to adjust substrate use to substrate availability (metabolic flexibility, MF), which may precede glucose intolerance in the pathogenesis of insulin resistance. We and others have shown that frequent interruptions in SB leads to improved glycemic control, however the underlying role of MF in this process is unknown. This study examined the effects of breaking up SB on MF and glucose metabolism in free-living overweight and obese adults. To distinguish effects of breaking up SB from being physically active, we also studied a group where participants performed a single energy matched continuous bout of exercise. METHODS: Physically inactive, adults (12F/7M, mean±SD; 33±8 yrs, BMI = 29.5±3.3kg/m2) were randomly assigned to a 4 week intervention consisting of brisk walking for 5 min each hour for 10h, 5 d/wk (MICRO), or 4 weeks of an intervention consisting of one continuous 45 min bout of exercise per day, 5d/wk (ONE). Outcomes assessed at baseline and after each intervention included: MF (waking respiratory quotient,RQ, minus sleeping RQ as measured in a whole room calorimeter), insulin sensitivity (SI, IVGTT), 24h glycaemia (continuous glucose monitor), 24h glucose oxidation (U13C glucose tracer), SB, time spent stepping, and performing moderate to vigorous activity (MVPA; ActivPAL and ActiGraph). Groups were similar on all outcome variables at baseline. Linear mixed models evaluated intervention and intervention-by-group effects. RESULTS: MICRO and ONE decreased time sitting (-43.5±93.4 min), increased time stepping (+26.3±44.0 min) and time spent in MVPA (+9.8±17.6 min) (p<0.05 for all). No significant changes were observed in SI, but both interventions decreased fasting insulin and HOMA IR (p<0.05 for both). Compared to ONE, MICRO improved the acute insulin response to glucose (AIRg), lowered 24h glycemic variability, maintained exogenous glucose oxidation, and improved MF (interaction: p<0.05 for all). Improvements in MF were positively associated with changes in SI (r=0.59, p=0.02). CONCLUSIONS: Independent of time sitting and stepping, breaking up SB improves glucose homeostasis and MF. The effects of such an intervention in persons with type 2 diabetes warrants further study.

MON-223 Adipose Insulin Resistance in Normal-Weight Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism and oligo-ovulation associated with insulin resistance (IR). Adipose-IR may underlie this PCOS phenotype and could contribute to IR by impairing insulin-mediated glucose uptake and/or lipogenesis, while diminishing insulin suppression of lipolysis. The present study examined whether adipose-IR, defined as the product of fasting circulating free fatty acid and insulin levels (1), was increased in normal-weight PCOS versus age-/BMI-balanced normo-androgenic ovulatory (control) women and, if so, whether it correlated with insulin sensitivity (Si) as measured by frequently-sampled intravenous glucose tolerance testing (FSIVGTT) and/or hyperandrogenism. Ten normal-weight PCOS women (by NIH criteria) and 18 controls (19-35 years; 19-25 kg/m2) of non-Hispanic Caucasian descent underwent serum hormone/metabolic measurements, FSIVGTT, total body dual-energy x-ray absorptiometry, and subcutaneous (SC) abdominal fat biopsy. Circulating hormone/metabolite levels, adipose-IR, Si, acute insulin response to glucose (AIRg), body fat distribution and adipocyte size distribution were compared between female types using Student’s t-test. Partial correlation coefficients examined associations between adipose-IR and outcome variables, adjusting for serum androgen levels. PCOS women exhibited greater serum LH, androstenedione (A4), total testosterone (T) and free (f) T levels than controls (P<0.05, all parameters), and demonstrated trends for increased abdominal adiposity (P=0.06) and serum triglyceride (TG) levels (P=0.09) with low-normal Si values. PCOS women also had greater (P=0.007) adipose-IR than controls, with a value of 29 pM/L*mM/L providing 94% specificity (95% CI 84%-100%) and 80% sensitivity (95% CI 55%-100%) in discriminating PCOS subjects from controls (AUC=0.81, 95% CI 0.61-1.00, P<0.001). In all women combined, adipose-IR negatively correlated with Si (P=0.01) and positively correlated with serum A4 (P=0.002), total T (P=0.004), fT (P=0.001) and fasting TG (P=0.001) levels as well as with AIRg (P=0.03) and percent small SC abdominal adipocytes (P=0.01). Relationships of adipose-IR with Si (P=0.04) and with serum TG (P=0.01) levels remained after adjusting for serum total T and fT levels, respectively, while the other correlations lost significance. Thus, in normal-weight PCOS women, adipose-IR is intimately linked with dyslipidemia and is associated with reduced Si in part through hyperandrogenism. Reference: Sondergaard E, et al. JCEM 2017;102:1193. Sources of Research Support: NIH Grants and Santa Monica Bay Woman’s Club.