Beta-cell Function Research Articles

Four weeks SGLT2 inhibition improves beta cell function and glucose tolerance without affecting muscle free fatty acid or glucose uptake in subjects with type 2 diabetes.

Sodium glucose co-transporter-2 (SGLT2) inhibition lowers glucose levels independently of insulin, leading to reduced insulin secretion and increased lipolysis, resulting in elevated circulating free fatty acids (FFAs). While SGLT2 inhibition improves tissue insulin sensitivity, the increase in circulating FFAs could reduce insulin sensitivity in skeletal muscle and the liver. We aimed to investigate the effects of SGLT2 inhibition on substrate utilization in skeletal muscle and the liver and to measure beta-cell function and glucose tolerance. Thirteen metformin-treated individuals with type 2 diabetes were randomized to once-daily empagliflozin 25 mg or placebo for 4 weeks in a crossover design. Skeletal muscle glucose and FFA uptake together with hepatic tissue FFA uptake were measured using [18F]FDG positron emission tomography/computed tomography (PET/CT) and [11C]palmitate PET/CT. Insulin secretion and action were estimated using the oral minimal model. Empagliflozin did not affect glucose (0.73 ± 0.30 vs. 1.16 ± 0.64, μmol/g/min p = 0.11) or FFA (0.60 ± 0.30 vs. 0.56 ± 0.3, μmol/g/min p = 0.54) uptake in skeletal muscle. FFA uptake in the liver (21.2 ± 10.1 vs. 19 ± 8.8, μmol/100 ml/min p = 0.32) was unaffected. Empagliflozin increased total beta-cell responsivity (20 ± 8 vs. 14 ± 9, 10-9min-1, p < 0.01) and glucose effectiveness (2.6 × 10-2 ± 0.3 × 10-2 vs. 2.4 × 10-2 ± 0.3 × 10-2, dL/kg/min, p = 0.02). Despite improved beta-cell function and glucose tolerance, empagliflozin does not appear to affect skeletal muscle FFA or glucose uptake.

Glycemic variability assessed using continuous glucose monitoring in individuals without diabetes and associations with cardiometabolic risk markers: A systematic review and meta-analysis

Continuous glucose monitoring (CGM) provides data on short-term glycemic variability (GV). GV is associated with adverse outcomes in individuals with diabetes. Whether GV is associated with cardiometabolic risk in individuals without diabetes is unclear. We systematically reviewed the literature to assess whether GV is associated with cardiometabolic risk markers or outcomes in individuals without diabetes. Searches were performed in PubMed/Medline, Embase and Cochrane from inception through April 2022. Two researchers were involved in study selection, data extraction and quality assessment. Studies evaluating GV using CGM for ≥24h were included. Studies in populations with acute and/or critical illness were excluded. Both narrative synthesis and meta-analyzes were performed, depending on outcome. Seventy-one studies were included; the majority were cross-sectional. Multiple measures of GV are higher in individuals with compared to without prediabetes and GV appears to be inversely associated with beta cell function. In contrast, GV is not clearly associated with insulin sensitivity, fatty liver disease, adiposity, blood lipids, blood pressure or oxidative stress. However, GV may be positively associated with the degree of atherosclerosis and cardiovascular events in individuals with coronary disease. GV is elevated in prediabetes, potentially related to beta cell dysfunction, but less clearly associated with obesity or traditional risk factors. GV is associated with coronary atherosclerosis development and may predict cardiovascular events and type 2 diabetes. Prospective studies are warranted, investigating the predictive power of GV in relation to incident disease. GV may be an important risk measure also in individuals without diabetes.

Effects of vitamin D and/or calcium intervention on sleep quality in individuals with prediabetes: a post hoc analysis of a randomized controlled trial.

The aim of this study was to evaluate the effects of vitamin D and/or calcium supplementation on sleep quality in individuals with prediabetes. A 24-week randomized controlled trial (RCT) was conducted in a 212 Chinese population with prediabetes. Participants were randomly assigned to four groups: vitamin D + calcium group (1600IU/day + 500mg/day, n = 53), vitamin D group (1600IU/day, n = 54), calcium group (500mg/day, n = 51), and control group (placebo, n = 54). The Pittsburgh Sleep Quality Index (PSQI) was used as the primary outcome to assess sleep quality. Questionnaires and fasting blood samples were collected at baseline and post-intervention for demographic assessment and correlation index analysis. After a 24-week intervention, a significant difference was observed in serum 25(OH)D concentration among the four groups (P < 0.05), and the total PSQI score in vitamin D + calcium group was lower compared to the preintervention levels. Subgroup analyses revealed improved sleep quality with calcium supplementation (P < 0.05) for specific groups, including women, individuals with a low baseline 25(OH)D level (< 30ng/mL), and individuals in menopause. Moreover, correlation analysis revealed a negative correlation between the extent of change in sleep efficiency scores before and after the calcium intervention and the degree of change in insulin efficiency scores (r = - 0.264, P = 0.007), as well as the magnitude of change in islet beta cell function (r = - 0.304, P = 0.002). The combined intervention of vitamin D and calcium, as well as calcium interventions alone, exhibits substantial potential for improving sleep quality in individuals with prediabetes. The trial was registered in August 2019 as ChiCTR190002487.

Efficacy and safety of enavogliflozin vs. dapagliflozin as add-on therapy in patients with type 2 diabetes mellitus based on renal function: a pooled analysis of two randomized controlled trials

BackgroundWe assessed the efficacy and safety of enavogliflozin (0.3 mg), a newly developed SGLT-2 inhibitor, in patients with type 2 diabetes mellitus based on kidney function via pooled analysis of two 24-week, randomized, double-blind phase III trials.MethodsData from 470 patients were included (enavogliflozin: 0.3 mg/day, n = 235; dapagliflozin: 10 mg/day, n = 235). The subjects were classified by mildly reduced (60 ≤ eGFR < 90 mL/min/1.73 m², n = 247) or normal eGFR (≥ 90 mL/min/1.73 m², n = 223).ResultsIn the mildly reduced eGFR group, enavogliflozin significantly reduced the adjusted mean change of HbA1c and fasting plasma glucose levels at week 24 compared to dapagliflozin (− 0.94% vs. −0.77%, P = 0.0196). Enavogliflozin exhibited a more pronounced glucose-lowering effect by HbA1c when combined with dipeptidyl peptidase-4 inhibitors than that observed in their absence. Enavogliflozin showed potent blood glucose-lowering effects regardless of renal function. Conversely, dapagliflozin showed a significant decrease in the glucose-lowering efficacy as the renal function decreased. Enavogliflozin showed a higher urinary glucose excretion rate in both groups. The homeostatic model assessment showed that enavogliflozin markedly decreased the insulin resistance. The blood pressure, weight loss, or homeostasis model assessment of beta-cell function values did not differ significantly between enavogliflozin and dapagliflozin. Adverse events were similar between both drugs.ConclusionsThe glucose-lowering efficacy of enavogliflozin is superior to that of dapagliflozin in patients with type 2 diabetes mellitus with mild renal function impairment; this is attributed to its potent urinary glucose excretion-promoting ability. The emergence of new and potent SGLT-2 inhibitors is considered an attractive option for patients with inadequate glycemic control and decreased renal function.Trial registrationNot applicable (pooled analysis).

A mandatory practice in type 2 diabetes mellitus to maintain quality of life

Nepalese owing to modern lifestyle and processed food are racially at an elevated risk of acquiring central obesity-related insulin resistance (IR) and thus Type 2 diabetes mellitus (T2DM) and Diabetic Kidney Disease (DKD). Low birth weight in utero and later becoming obese risks the development of T2DM. In a total of eighty-four newly diagnosed treatment-naive Nepalese T2DMs, incidence of IR, percentage beta-cell function (%BCF) and percentage insulin sensitivity (%IS) were determined using Homeostatic Model Assessment 2 (HOMA2-IR). Association of HOMA2-IR with albuminuria, kidney function, hs-CRP, fatty liver, fatty pancreas, several anthropometric and biochemical parameters were analyzed. Among the eighty-four T2DMs, fifty-four agreeing regular follow-ups were prescribed a low-carbohydrate diet (&amp;#60;130gm/day). At 6 months, their glycemic controls were monitored. From 84 newly diagnosed T2DMs, 56 (66.7%) were insulin resistant and 28(33.3%) insulin-sensitive on HOMA2-IR. There was a significant association of HOMA2-IR with albuminuria and declining kidney function (p=0.006 and 0.034 respectively) and most of them were at reversible stages. Waist circumference (WC), waist-hip ratio (WHR), lipid profile ratios, fatty liver and fatty pancreas were elucidated as potential markers for IR. The IS group (ISG) had significantly inadequate %BCF (p=0.001) but high %IS (p&amp;#60;0.001) has healthier WHR (p=0.001) and lipid profile ratios which are opposite to IR group (IRG). 13 ISG had raised hs-CRP and 15 normal and 21 IRG had normal hs-CRP and 35 raised. At 6 months, the IRG achieved significantly better postprandial glycemic goals (p=0.04) and significant improvement in WC and WHR (p=0.008 and 0.03 respectively) with a low-carbohydrate diet as compared to ISG. Severe insulin resistance and IR-associated DKD, fatty liver and fatty pancreas are highly prevalent from the time of diagnosis of T2DM in the Nepalese population. Thus inspecting for IR and its consequences mandatorily at diagnosis and applying precision therapies like adjustments in the quality and quantity of staple food carbohydrates significantly improves IR-related parameters and glycemia.

Keeping pace: the primary cilium as the conducting baton of the islet.

Primary cilia are rod-like sensory organelles that protrude from the surface of most mammalian cells, including the cells of the islet, and mounting evidence supports important roles of these structures in the regulation of beta cell function and insulin secretion. The sensory abilities of the cilium arise from local receptor activation that is coupled to intrinsic signal transduction, and ciliary signals can propagate into the cell and influence cell function. Here, we review recent advances and studies that provide insights into intra-islet cues that trigger primary cilia signalling; how second messenger signals are generated and propagated within cilia; and how ciliary signalling affects beta cell function. We also discuss the potential involvement of primary cilia and ciliary signalling in the development and progression of type 2 diabetes, identify gaps in our current understanding of islet cell cilia function and provide suggestions on how to further our understanding of this intriguing structure.

GLP1R and GIPR expression and signaling in pancreatic alpha cells, beta cells and delta cells

Glucagon-like peptide-1 receptor (GLP1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are transmembrane receptors involved in insulin, glucagon and somatostatin secretion from the pancreatic islet. Therapeutic targeting of GLP1R and GIPR restores blood glucose levels in part by influencing beta cell, alpha cell and delta cell function. Despite the importance of the incretin-mimetics for diabetes therapy, our understanding of GLP1R and GIPR expression patterns and signaling within the islet remain incomplete. Here, we present the evidence for GLP1R and GIPR expression in the major islet cell types, before addressing signaling pathway(s) engaged, as well as their influence on cell survival and function. While GLP1R is largely a beta cell-specific marker within the islet, GIPR is expressed in alpha cells, beta cells, and (possibly) delta cells. GLP1R and GIPR engage Gs-coupled pathways in most settings, although the exact outcome on hormone release depends on paracrine communication and promiscuous signaling. Biased agonism away from beta-arrestin is an emerging concept for improving therapeutic efficacy, and is also relevant for GLP1R/GIPR dual agonism. Lastly, dual agonists exert multiple effects on islet function through GIPR > GLP1R imbalance, increased GLP1R surface expression and cAMP signaling, as well as beneficial alpha cell-beta cell-delta cell crosstalk.

Evidence for C-Peptide as a Validated Surrogate to Predict Clinical Benefits in Trials of Disease-Modifying Therapies for Type 1 Diabetes.

Type 1 diabetes is a chronic autoimmune disease in which destruction of pancreatic beta cells causes life-threatening metabolic dysregulation. Numerous approaches are envisioned for new therapies, but limitations of current clinical outcome measures are significant disincentives to development efforts. C-peptide, a direct byproduct of proinsulin processing, is a quantitative biomarker of beta cell function that is not cleared by the liver and can be measured in the peripheral blood. Studies of quantitative measures of beta cell function have established a predictive relationship between stimulated C-peptide as a measure of beta cell function and clinical benefits. C-peptide levels at diagnosis are often high enough to afford glycemic control benefits associated with protection from end-organ complications of diabetes, and even lower levels offer protection from severe hypoglycemia in type 1 diabetes, as observed in large prospective cohort studies and interventional trials of islet transplantation. These observations support consideration of C-peptide not just as a biomarker of beta cell function, but also as a specific, sensitive, feasible, and clinically meaningful outcome defining beta cell preservation or restoration for clinical trials of disease-modifying therapies. Regulatory acceptance of C-peptide as a validated surrogate for demonstration of efficacy would greatly facilitate development of disease-modifying therapies for type 1 diabetes.

Malondialdehyde Serum Levels in a Full Characterized Series of 430 Rheumatoid Arthritis Patients

Background. Oxidative stress has been involved in the pathogenesis of rheumatoid arthritis (RA). The serum malondialdehyde (MDA) level is a reliable biomarker of oxidative stress status. In the present work, we aimed to analyze how a comprehensive characterization of the disease characteristics in RA, including a lipid profile, insulin resistance, and subclinical atherosclerosis, relates to serum MDA levels. Methods. In a cross-sectional study that included 430 RA patients, serum MDA levels were evaluated. Multivariable analysis was performed to examine the relationship of MDA with disease activity scores and disease characteristics, including subclinical carotid atherosclerosis, a comprehensive lipid molecule profile, and indices of insulin resistance and beta cell function indices. Results. The erythrocyte sedimentation rate (ESR) showed a significant and positive relationship with MDA. However, this did not occur for other acute phase reactants such as C-reactive protein or interleukin-6. Although the DAS28-ESR score (Disease Activity Score in 28 joints) had a positive and significant association with MDA serum levels, other disease activity scores that do not use the erythrocyte sedimentation rate in their formula did not show a significant relationship with MDA. Other disease characteristics, such as disease duration and the existence of rheumatoid factor and antibodies against citrullinated protein, were not related to serum MDA levels. This also occurred for lipid profiles, insulin resistance indices, and subclinical carotid atherosclerosis, for which no associations with circulating MDA were found. Conclusions. The disease characteristics are not related to circulating MDA levels in patients with RA.

Approaches to Measuring Beta Cell Reserve and Defining Partial Clinical Remission in Paediatric Type 1 Diabetes.

Type 1 diabetes (T1D) results from the autoimmune T-cell mediated destruction of pancreatic beta cells leading to insufficient insulin secretion. At the time of diagnosis of T1D, there is residual beta cell function that declines over the subsequent months to years. Recent interventions have been approved to preserve beta cell function in evolving T1D. The aim of this review is to summarise the approaches used to assess residual beta cell function in evolving T1D, and to highlight potential future directions. Studies including subjects aged 0 to 18 years were included in this review. The following search terms were used; "(type 1 diabetes) and (partial remission)" and "(type 1 diabetes) and (honeymoon)". References of included studies were reviewed to determine if additional relevant studies were eligible. There are numerous approaches to quantifying beta cell reserve in evolving T1D. These include c-peptide measurement after a mixed meal or glucagon stimuli, fasting c-peptide, the urinary c-peptide/creatinine ratio, insulin dose-adjusted haemoglobin A1c, and other clinical models to estimate beta cell function. Other biomarkers may have a role, including the proinsulin/c-peptide ratio, cytokines, and microRNA. Studies using thresholds to determine if residual beta cell function is present often differ in values used to define remission. As interventions are approved to preserve beta cell function, it will become increasingly necessary to quantify residual beta cell function in research and clinical contexts. In this report, we have highlighted the strengths and limitations of the current approaches.

Prolonged Remission Induced by FENofibrate in children with newly diagnosed type 1 diabetes (PRIFEN): protocol of a randomised controlled trial

IntroductionSphingolipids regulate proinsulin folding, insulin secretion and control beta cells apoptosis. Recent evidence has demonstrated that, among other factors, reduced amounts of sulfatide may be relevant in the development of...

Glucometabolism in Kidney Transplant Recipients with and without Posttransplant Diabetes: Focus on Beta-Cell Function.

Posttransplant diabetes mellitus (PTDM) is a common complication after kidney transplantation. Pathophysiologically, whether beta-cell dysfunction rather than insulin resistance may be the predominant defect in PTDM has been a matter of debate. The aim of the present analysis was to compare glucometabolism in kidney transplant recipients with and without PTDM. To this aim, we included 191 patients from a randomized controlled trial who underwent oral glucose tolerance tests (OGTTs) 6 months after transplantation. We derived several basic indices of beta-cell function and insulin resistance as well as variables from mathematical modeling for a more robust beta-cell function assessment. Mean ± standard deviation of the insulin sensitivity parameter PREDIM was 3.65 ± 1.68 in PTDM versus 5.46 ± 2.57 in NON-PTDM. Model-based glucose sensitivity (indicator of beta-cell function) was 68.44 ± 57.82 pmol∙min-1∙m-2∙mM-1 in PTDM versus 143.73 ± 112.91 pmol∙min-1∙m-2∙mM-1 in NON-PTDM, respectively. Both basic indices and model-based parameters of beta-cell function were more than 50% lower in patients with PTDM, indicating severe beta-cell impairment. Nonetheless, some defects in insulin sensitivity were also present, although less marked. We conclude that in PTDM, the prominent defect appears to be beta-cell dysfunction. From a pathophysiological point of view, patients at high risk for developing PTDM may benefit from intensive treatment of hyperglycemia over the insulin secretion axis.

Insulin sensitivity and beta cell function after duodenal mucosal resurfacing: an open-label, mechanistic, pilot study

Background and AimsThe duodenum has been shown to play a key role in glucose homeostasis. Duodenal mucosal resurfacing (DMR) is an endoscopic procedure for patients with type 2 diabetes (T2D) in which the duodenal mucosa is hydrothermally ablated. DMR improves glycemic control, but the underlying mechanisms remain unclear. Here, we report changes in glucoregulatory hormones and indices of insulin sensitivity and beta cell function after DMR. MethodsWe included 28 patients on non-insulin glucose lowering medications who underwent open-label DMR and a mixed meal test (MMT) in Revita-1 or Revita-2. Inclusion criteria were hemoglobin A1c (HbA1c) 7.6-10.4% and BMI 24-40kg/m2. Baseline and 3-months MMT data included plasma glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), and gastric inhibitory polypeptide (GIP) concentrations. Glucoregulatory hormones, insulin sensitivity indices (homeostatic model assessment for insulin resistance [HOMA-IR], Matsuda index [MI] and hepatic insulin resistance [HIR]), and beta cell function (insulinogenic index [IGI], disposition index [DI] and insulin secretion rate [ISR]) were assessed. ResultsFasting insulin, glucagon, and C-peptide decreased significantly. Insulin sensitivity (HOMA-IR, MI, and HIR) and beta cell function (DI and ISR) all improved significantly. Decline in postprandial glucose, mainly driven by a decrease in fasting levels, was observed, as well as a decline in postprandial glucagon whereas GLP-1 and GIP did not change. ConclusionsInsulin sensitivity and insulin secretion improved 3 months after DMR. It is unlikely that incretin changes are responsible for improved glucose control after DMR. These data add to the growing evidence validating the duodenum as a therapeutic target for patients with T2D.

Baricitinib for preservation of beta-cell function in type 1 diabetes

Baricitinib for preservation of beta-cell function in type 1 diabetes

Low-Dose Sulfonylurea Plus DPP4 Inhibitor Lower Blood Glucose and Enhance Beta-Cell Function Without Hypoglycemia.

Low-dose sulfonylureas (SUs) have been found to augment the classical incretin effect, increase glucose sensitivity and late phase incretin potentiation. To evaluate potential synergy between low-dose SU plus a dipeptidyl peptidase 4 (DPP4) inhibitor. Unblinded randomized crossover study at the Clinical Research Centre, University of Dundee. Thirty participants with T2DM (HbA1c < 64 mmol/mol) were treated with diet or metformin. Participants completed 4, 14-day blocks in a random order: control, gliclazide 20 mg (SU), sitagliptin 100 mg (DPP4 inhibitor [DPP4i]), or combination (SUDPP4i). A mixed meal test was conducted after each intervention. The primary outcome was the effect of treatment on beta-cell glucose sensitivity. Secondary outcomes included frequency of glucose <3 mmol/L on continuous glucose monitoring, subanalyses by genotype (KNCJ11 E23K), gender, and body mass index. SU combination with DPP4i showed additive effect on glucose lowering: mean glucose area under the curve (mean 95% CI) (mmol/L) was control 11.5 (10.7-12.3), DPP4i 10.2 (9.4-11.1), SU 9.7 (8.9-10.5), SUDPP4i 8.7 (7.9-9.5) (P < .001). Glucose sensitivity mirrored the additive effect (pmol min-1 m-2 mM-1): control 71.5 (51.1-91.9), DPP4i 75.9 (55.7-96.0), SU 86.3 (66.1-106.4), SUDPP4i 94.1 (73.9-114.3) (P = .04). The additive effect was seen in men but not women. Glucose time in range <3 mmol/L on continuous glucose monitoring (%) was unaffected: control 1 (2-4), DPP4i 2 (3-6), SU 1 (0-4), SUDPP4i 3 (2-7) (P = .65). Low-dose sulfonylurea plus DPP4i has a potent glucose-lowering effect through augmentation of beta-cell function. A double-blind randomized controlled trial would formalize efficacy and safety of this combination, which may avoid negative aspects of SU.

DNA Methylation-Based Assessment of Cell Composition in Human Pancreas and Islets.

Assessment of pancreas cell type composition is crucial to the understanding of the genesis of diabetes. Current approaches use immunodetection of protein markers, for example insulin as a marker of beta-cells. A major limitation of these methods is that protein content varies in physiological and pathological conditions, complicating the extrapolation to actual cell number. Here we demonstrate the use of cell type-specific DNA methylation markers for determining the fraction of specific cell types in human islet and pancreas specimens. We identified genomic loci that are uniquely demethylated in specific pancreatic cell types and applied targeted PCR to assess the methylation status of these loci in tissue samples, enabling inference of cell type composition. In islet preparations, normalization of insulin secretion to beta-cell DNA revealed similar beta-cell function in pre-T1D, T1D and T2D , which was significantly lower than in non-diabetic donors. In histological pancreas specimens from recent-onset T1D this assay showed beta-cell fraction within the normal range, suggesting a significant contribution of beta-cell dysfunction. In T2D pancreata we observed increased alpha-cell fraction and normal beta-cell fraction. Methylation-based analysis provides an accurate molecular alternative to immune detection of cell types in the human pancreas, with utility in the interpretation of insulin secretion assays and the assessment of pancreas cell composition in health and disease.

Tirzepatide Improved Markers of Islet Cell Function and Insulin Sensitivity in People With T2D (SURPASS-2).

In previous SURPASS studies tirzepatide reduced hemoglobin glycated A1c (HbA1c) and body weight and improved markers of insulin sensitivity and β-cell function to a greater extent than comparators. Explore changes in biomarkers of β-cell function and insulin sensitivity and in efficacy profiles in baseline biomarker quartile analyses with tirzepatide compared to semaglutide. Post hoc analysis of SURPASS-2 phase 3 trial (participants randomly assigned to receive weekly subcutaneous tirzepatide or semaglutide for 40 weeks). Post hoc analysis of 128 sites in 8 countries. A total of 1879 participants with type 2 diabetes. Once-weekly tirzepatide (5, 10, 15 mg) or semaglutide 1 mg. Change in homeostatic model assessment indices for pancreatic β-cell function (HOMA2-B) and for insulin resistance (HOMA2-IR), fasting glucagon, fasting C-peptide, and fasting insulin. At week 40, a greater increase in HOMA2-B was seen with tirzepatide (5, 10, 15 mg) doses (96.9-120.4%) than with semaglutide 1 mg (84.0%) (P < .05). There was a greater reduction in HOMA2-IR with all doses of tirzepatide (15.5%-24.0%) than with semaglutide 1 mg (5.1%) (P < .05). Tirzepatide 10 and 15 mg resulted in a significant reduction in both fasting C-peptide (5.2%-6.0%) and fasting glucagon (53.0%-55.3%) compared with an increase of C-peptide (3.3%) and a reduction of glucagon (47.7%) with semaglutide 1 mg (P < .05). HbA1c and body weight reductions were greater with all tirzepatide doses than semaglutide within each HOMA2-B and HOMA2-IR baseline quartile. In this post hoc analysis, improvements in HbA1c and weight loss were consistent and significantly higher with tirzepatide, regardless of baseline β-cell function and insulin resistance, compared with semaglutide.

Insulin resistance and impaired insulin secretion and gastrointestinal cancer risk in Korean adults: Preliminary results from Korean Genome and Epidemiology study.

761 Background: To date, few studies conducted on the effect of insulin resistance or insulin secretory function on cancer risk in non-diabetic population. This study evaluated whether insulin resistance and/or insulin secretory function affect gastrointestinal cancer risk in the Korean population. Methods: We analyzed data from Korean Genome and Epidemiology Study, Korea Association Resource dataset. It consists of 10,030 participants aged 40-69y observed from 2001 to 2018. The risk of all cancers, and gastrointestinal cancers were assessed. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Homeostasis Model Assessment of Beta-cell function (HOMA-β) were used as indicators of insulin resistance and insulin secretory function. Results: In the final dataset, 8,649 individuals without previous history of any cancers were included. During an average follow-up of 15 years, 415 subjects (4.8%) developed cancers. Compared to the low HOMA-IR/high HOMA-β group (reference), diabetic patients had the highest risk of overall cancers, followed by high HOMA-IR/low HOMA-β group (Adjusted hazard ratio[95% confidence interval]: 1.74 [1.11 - 2.75] and 1.40 [0.96 – 2.06], respectively) Among gastrointestinal cancers, the risk of gastric cancer was higher in the low HOMA-IR/low HOMA-β and high HOMA-IR/high HOMA-β groups (1.92 [1.06 - 3.47] and 2.27 [1.26 - 4.06], respectively) When further analyzed by HOMA-β stratified by quartiles, the lowest quartile (Q1) showed an increased risk of gastric cancer compared to the highest-quartile (Q4; 1.84 [0.98 – 3.46], p = 0.06) In contrast, no significant results were observed regarding the colorectal cancer risk, when analyzed based on HOMA-IR and HOMA-β. However, when further analyzed by HOMA-IR stratified by quartiles, the highest quartile (Q4) exhibited a significantly elevated colorectal cancer risk compared to the lowest quartile (Q1; 2.14 [1.11 - 4.11], P for trend = 0.04). Conclusions: Insulin resistance and impaired insulin secretion function may increase the risk of cancer, but the underlying mechanisms may differ by cancer type.

Telomere Maintenance Is Associated with Type 2 Diabetes Remission in Response to a Long-Term Dietary Intervention without Non-Weight Loss in Patients with Coronary Heart Disease: From the CORDIOPREV Randomized Controlled Trial.

In order to evaluate whether telomere maintenance is associated with type 2 diabetes remission, newly diagnosed type 2 diabetes patients without glucose-lowering treatment (183 out of 1002) from the CORDIOPREV study (NCT00924937) were randomized to consume a Mediterranean or low-fat diet. Patients were classified as Responders, those who reverted from type 2 diabetes during the 5 years of dietary intervention (n = 69), and Non-Responders, who did not achieve diabetes remission by the end of the follow-up period (n = 104). We found no differences in diabetes remission between the two diets, and we determined telomere length (TL) by measuring qPCR, telomerase activity using the TRAP assay, and direct redox balance based on the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSH) via colorimetric assay. Responders exhibited higher baseline TL in comparison with Non-Responders (p = 0.040), and a higher TL at baseline significantly predicted a higher probability of type 2 diabetes remission (OR 2.13; 95% CI, 1.03 to 4.41). After the dietary intervention, Non-Responders showed significant telomere shortening (-0.19, 95% CI -0.32 to 0.57; p = 0.005). Telomere shortening was significantly pronounced in type 2 diabetes patients with a worse profile of insulin resistance and/or beta-cell functionality: high hepatic insulin resistance fasting, a high disposition index (-0.35; 95% CI, -0.54 to -0.16; p < 0.001), and a low disposition index (-0.25; 95% CI, -0.47 to -0.01; p = 0.037). In addition, changes in TL were correlated to the GSH/GSSG ratio. Responders also showed increased telomerase activity compared with baseline (p = 0.048), from 0.16 (95% CI, 0.08 to 0.23) to 0.28 (95% CI, 0.15 to 0.40), with a more marked increase after the dietary intervention compared with Non-Responders (+0.07; 95% CI, -0.06-0.20; p = 0.049). To conclude, telomere maintenance may play a key role in the molecular mechanisms underlying type 2 diabetes remission in newly diagnosed patients. However, further larger-scale prospective studies are necessary to corroborate our findings.

Sox9 regulates alternative splicing and pancreatic beta cell function

Despite significant research, mechanisms underlying the failure of islet beta cells that result in type 2 diabetes (T2D) are still under investigation. Here, we report that Sox9, a transcriptional regulator of pancreas development, also functions in mature beta cells. Our results show that Sox9-depleted rodent beta cells have defective insulin secretion, and aging animals develop glucose intolerance, mimicking the progressive degeneration observed in T2D. Using genome editing in human stem cells, we show that beta cells lacking SOX9 have stunted first-phase insulin secretion. In human and rodent cells, loss of Sox9 disrupts alternative splicing and triggers accumulation of non-functional isoforms of genes with key roles in beta cell function. Sox9 depletion reduces expression of protein-coding splice variants of the serine-rich splicing factor arginine SRSF5, a major splicing enhancer that regulates alternative splicing. Our data highlight the role of SOX9 as a regulator of alternative splicing in mature beta cell function.