Introduction:Paraoxonase 1 (PON1) is a liver-derived HDL-associated enzyme with key antioxidant functions implicated in cardiometabolic disease. Genetic variation in PON1 strongly influences enzyme activity; however, whether specific genetic configurations contribute to dysglycemia and metabolic liver risk beyond enzymatic activity remains unclear. Methods:We analyzed 922 individuals from the PREVADIAB2 cohort to investigate the relationship between PON1 genetic variation, serum paraoxonase (PONase) activity, and dysmetabolic phenotypes. Genetic determinants of PONase activity were identified using genome-wide analysis. Independent variants were combined into haplotypes, and their associations with dysglycemia and metabolic liver risk (Fibrotic NASH Index, FNI) were assessed in individuals aged >55 years. Results:Two independent PON1 variants-rs2057681 (in strong linkage disequilibrium with Q192R) and the promoter variant rs854572-were identified as major determinants of PONase activity. Haplotype analysis revealed that promoter-transcribed region combinations exert graded effects on enzyme activity. Importantly, these genetic configurations were differentially associated with dysglycemia and metabolic liver risk in a genotype-dependent manner. In carriers of the rs2057681 G allele, the C-A haplotype was associated with lower risk of dysglycemia and elevated FNI, whereas in rs2057681 AA homozygotes the same haplotype showed an opposite association with metabolic liver risk. Notably, despite strong genetic effects on PONase activity, enzyme activity itself was not directly associated with dysmetabolic phenotypes. Discussion:PON1 genetic architecture, defined by promoter- transcribed region interactions, is associated with dysglycemia and metabolic liver risk in a genotype-dependent manner beyond steady-state enzyme activity. These findings provide insight into the genetic regulation of metabolic risk and may help explain inconsistent associations of PON1 variants in cardiometabolic disease.

AIMS/HYPOTHESIS:Type 2 diabetes is a multifactorial condition whose greatest impact comes from its complications. We hypothesized that distinct insulin-derived mechanisms and lipid profiles discriminate sex differences and can be used to identify subjects at higher risk to develop diabetes-related complications. METHODS:The PREVADIAB2 study evaluated metabolic alterations after 5 years in individuals initially free of Type 2 Diabetes (PREVADIAB1). In this analysis, 953 participants were stratified into clusters using hierarchical clustering based on insulinogenic index (IGI), fasting insulin secretion rate, HOMA-IR, and fasting insulin clearance. A subset of participants (n = 488) had their lipidome assessed using LC/MS-QTOF. RESULTS:Four clusters were identified: Liver Sensitive (LS), Pancreas Glucose Sensitive (PGS), Insulin Deficient (ID), and Insulin Resistant (IR), each with distinct dysglycemia risk. While metabolic features were similar across sexes, the parameter thresholds differed, resulting in sex-specific lipidomic profiles. Women exhibited higher levels of circulating dihydroceramides (5.3 ± 1.9 vs. 4.7 ± 1.8, p < .001), associated with de novo ceramide synthesis, and elevated sphingomyelins (SM), suggesting altered lipid metabolism. Conversely, the ceramide-to-SM ratio was higher in men (1.04 ± .21 vs. .90 ± .18, p < .001). Except for the LS cluster, all other clusters exhibit distinct lipid signatures associated with metabolic dysfunction, further accentuated by specific lipid profile sex differences. CONCLUSIONS:Distinct insulin-related metabolic features and sex identify different phenotypes with distinct lipidome profiles, highlighting the need to place prediabetes in a broader context of metabolism beyond glucose.

Background: Exercise is known to provide multiple metabolic benefits such as improved insulin sensitivity and glucose control in individuals with type 2 diabetes mellitus (T2DM) and those at risk. Beyond the traditional exercise dose, exercise timing is perceived as a contemporary hot-topic, especially in the field of T2DM, however, the number of intervention studies assessing exercise timing and glucose metabolism is scarce. Our aim is to test the effect of exercise timing (i.e., morning, afternoon, or evening) on the inter-individual response variability in glycemic control and related metabolic health parameters in individuals with T2DM and those at risk during a 12-week intervention. Methods: A randomized cross-over exercise intervention will be conducted involving 2 groups: Group 1, individuals with T2DM; Group 2, age-matched older adults with overweight/obesity. The intervention will consist of 3, 2-week blocks of supervised post-prandial exercise using high-intensity interval training (HIIT). Between each training block, a 2-week washout period, where participants avoid structured exercise, will take place. Assessments will be conducted in both groups before and after each exercise block. The primary outcomes include the 24-hour area under the curve continuous glucose monitoring based glucose. The secondary outcomes include body composition, resting energy expenditure, insulin response to a meal tolerance test, maximal aerobic capacity, peak power output, physical activity, sleep quality, and insulin and glucose levels. All primary and secondary outcomes will be measured at each assessment point. Discussion: Outcomes from this trial will provide us additional insight into the role of exercise timing on the inter-individual response variability in glycemic control and other related metabolic parameters in two distinct populations, thus contributing to the development of more effective exercise prescription guidelines for individuals with T2DM and those at risk. Trial registration: This study was retrospectively registered, and the details are at: https://clinicaltrials.gov/study/NCT06136013; Registered 18 November 2023.

BACKGROUND:Type 2 diabetes (T2DM) and obesity are characterized by altered insulin metabolism and action. Reduced hepatic insulin clearance is increasingly recognized as a key contributor to hyperinsulinemia and insulin resistance. CEACAM1 promotes hepatic insulin clearance, and its loss in hepatocytes is associated with reduced insulin clearance in mice and men. This study examines whether CEACAM1 circulating levels reflect compromised insulin metabolism and resistance in the PREVADIAB2 cohort. METHODS:A total of 1019 individuals from the PREVADIAB2 cohort were evaluated for diabetes by 75 g-OGTT and classified according to WHO 2019 criteria. CEACAM1 circulating levels were measured by ELISA, and insulin metabolism parameters were calculated. Hierarchical clustering of insulin metabolic indices and CEACAM1 levels was performed. Statistical significance was assessed using Kruskal-Wallis and Wilcoxon-Mann-Whitney tests. RESULTS:BMI, insulin resistance (HOMA-IR), and hepatic steatosis progressively increased with disease severity. Insulin secretion rose and its clearance declined in parallel to circulating CEACAM1 levels in prediabetes and T2DM, indicating compensatory hyperinsulinemia. Hierarchical metabolic clustering identified four clusters with distinct patterns and further showed that insulin clearance positively correlated with circulating CEACAM1, especially in individuals with normoglycemia, lower obesity and hepatic steatosis. This suggests that circulating CEACAM1 can reflect the status of hepatic insulin clearance. CONCLUSIONS:This study demonstrates a progressive increase in insulin resistance and hyperinsulinemia in parallel to elevated BMI and hepatic steatosis prevalence, accompanied by declining circulating CEACAM1 levels. Cluster analysis further linked reduced insulin clearance to lower circulating CEACAM1 levels, suggesting its potential usefulness as a biomarker for metabolic disease progression.

Type 2 diabetes mellitus (T2DM) is a disease that affects more than 380 million people worldwide. In this study, we developed a model, for these type of patients, that predicts blood glucose values over long prediction horizons (PHs), whose existence in the literature is almost nonexistent. These horizons allow patients to be warned in advance so that they can take action to avoid dangerous health situations. We used data from 3 of the 10 real patients available to test the implemented models. The overall results for the best model (simple Recurrent Neural Network) were: 34.82 mg/dL for root mean square error (RMSE) and 18.33% for mean absolute percentage error (MAPE) (PH = 2h); 46.59 mg/dL for RMSE and 24.35% for MAPE (PH = 4h).

Exercise is known to provide multiple metabolic benefits such as improved insulin sensitivity and glucose control in individuals with type 2 diabetes mellitus (T2DM) and those at risk. Beyond the traditional exercise dose, exercise timing is perceived as a contemporary hot topic, especially in the field of T2DM; however, the number of intervention studies assessing exercise timing and glucose metabolism is scarce. Our aim is to test the effect of exercise timing (i.e., morning, afternoon, or evening) on the inter-individual response variability in glycemic control and related metabolic health parameters in individuals with T2DM and those at risk during a 12-week intervention. A randomized crossover exercise intervention will be conducted involving two groups: group 1, individuals with T2DM; group 2, age-matched older adults with overweight/obesity. The intervention will consist of three 2-week blocks of supervised post-prandial exercise using high-intensity interval training (HIIT). Between each training block, a 2-week washout period, where participants avoid structured exercise, will take place. Assessments will be conducted in both groups before and after each exercise block. The primary outcomes include the 24-h area under the curve continuous glucose monitoring-based glucose. The secondary outcomes include body composition, resting energy expenditure, insulin response to a meal tolerance test, maximal aerobic capacity, peak power output, physical activity, sleep quality, and insulin and glucose levels. All primary and secondary outcomes will be measured at each assessment point. Outcomes from this trial will provide us additional insight into the role of exercise timing on the inter-individual response variability in glycemic control and other related metabolic parameters in two distinct populations, thus contributing to the development of more effective exercise prescription guidelines for individuals with T2DM and those at risk. ClinicalTrials.gov NCT06136013. Registered on November 18, 2023.

Type 2 diabetes (T2D) is a multifactorial condition whose greatest impact comes from its complications. Not only impaired glucose homeostasis, but also lipid alterations have a relevant role, with insulin derived mechanisms behind this milieu, i.e., glycemia and lipidemia. Thus, we hypothesized that a) distinct glucose and lipid profiles and b) sex differences, particularly in lipids patterns, may be used to identify subjects at higher risk to develop T2D. The PREVADIAB2 study evaluated metabolic alterations after 5 years in subjects without T2D when participating to PREVADIAB1. Herein, 953 subjects from the PREVADIAB2 cohort were stratified using a hierarchical clustering algorithm, informed by HOMA-IR, IGI, f ISR and f IC. The resulting clusters were profiled and the lipidome of a subset (n=488) was assessed by LC/MS-QTOF. We identified four clusters, named according to their main metabolic features: Liver Sensitive (LS); Pancreas Glucose Sensitive (PGS); Insulin Deficient (ID); and Insulin Resistant (IR). These cluster metabolic patterns were similar between sexes. However, men and women had distinct parameters cut-offs and lipidomic profiles. Overall, women presented higher long chain ceramides. Nonetheless, men had higher ceramide to sphingomyelin ratio and higher lysophosphatidylcholine to phosphatidylcholine ratio. For both genders, the LS cluster had the most advantageous lipid profile, whereas the other clusters presented lipid specificities towards dysmetabolism. This work shows that clustering individuals by distinct insulin-related metabolic features and sex identifies different phenotypes with distinct lipidome profile, thus demonstrating the importance of placing diabetes in a broader context of metabolism beyond glucose.

Coffee may protect against non-alcoholic fatty liver disease (NAFLD), but the roles of the caffeine and non-caffeine components are unclear. Coffee intake by 156 overweight subjects (87% with Type-2-Diabetes, T2D) was assessed via a questionnaire, with 98 subjects (all T2D) also providing a 24 h urine sample for quantification of coffee metabolites by LC–MS/MS. NAFLD was characterized by the fatty liver index (FLI) and by Fibroscan® assessment of fibrosis. No associations were found between self-reported coffee intake and NAFLD parameters; however, total urine caffeine metabolites, defined as Σcaffeine (caffeine + paraxanthine + theophylline), and adjusted for fat-free body mass, were significantly higher for subjects with no liver fibrosis than for those with fibrosis. Total non-caffeine metabolites, defined as Σncm (trigonelline + caffeic acid + p-coumaric acid), showed a significant negative association with the FLI. Multiple regression analyses for overweight/obese T2D subjects (n = 89) showed that both Σcaffeine and Σncm were negatively associated with the FLI, after adjusting for age, sex, HbA1c, ethanol intake and glomerular filtration rate. The theophylline fraction of Σcaffeine was significantly increased with both fibrosis and the FLI, possibly reflecting elevated CYP2E1 activity—a hallmark of NAFLD worsening. Thus, for overweight/obese T2D patients, higher intake of both caffeine and non-caffeine coffee components is associated with less severe NAFLD. Caffeine metabolites represent novel markers of NAFLD progression.

Introduction: In Non-Alcoholic Fatty Liver Disease (NAFLD), events driving early hepatic dysfunction with respect to specific metabolic pathways are still poorly known.Methods: We enrolled 84 subjects with obesity and/or type 2 diabetes (T2D). FibroScan (R) served to assess NAFLD by controlled attenuation parameter (CAP), and fibrosis by liver stiffness (LS). Patients with LS above 7 kPa were excluded. APRI and FIB-4 were used as additional serum biomarkers of fibrosis. The stable-isotope dynamic breath test was used to assess the hepatic efficiency of portal extraction (as DOB15) and microsomal metabo-lization (as cPDR30) of orally-administered (13C)-methacetin.Results: NAFLD occurred in 45%, 65.9%, and 91.3% of normal weight, overweight, and obese subjects, respec-tively. Biomarkers of liver fibrosis were comparable across subgroups, and LS was higher in obese, than in normal weight subjects. DOB15 was 23.2 +/- 1.5%o in normal weight subjects, tended to decrease in overweight (19.9 +/- 1.0%o) and decreased significantly in obese subjects (16.9 +/- 1.3, P = 0.008 vs. normal weight). Subjects with NAFLD had lower DOB15 (18.7 +/- 0.9 vs. 22.1 +/- 1.2, P = 0.03) but higher LS (4.7 +/- 0.1 vs. 4.0 +/- 0.2 kPa, P = 0.0003) than subjects without NAFLD, irrespective of fibrosis. DOB15 (but not cPDR30) decreased with increasing degree of NAFLD (R =-0.26; P = 0.01) and LS (R =-0.23, P = 0.03). Patients with T2D showed increased rate of NAFLD than those without T2D but similar LS, DOB15 and cPDR30.Conclusions: Overweight, obesity and liver fat accumulation manifest with deranged portal extraction efficiency of methacetin into the steatotic hepatocyte. This functional alteration occurs early, and irrespective of significant fibrosis and presence of T2D.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Nonalcoholic fatty liver disease (NAFLD) diagnosis without using invasive methods is extremely challenging, highlighting the need for simple indexes for this end. Recently, the fibrotic nonalcoholic steatohepatitis index (FNI) was developed and proposed as an affordable non-invasive score calculated with aspartate aminotransferase, high-density lipoprotein cholesterol and haemoglobin A1c. Herein, and given the link between NAFLD and diabetes, we aimed at validating FNI in a population with type 2 diabetes (T2D), also considering diabetes duration and glycaemic severity. The performance of FNI was higher than FIB-4 (AUROC = 0.89 vs 0.67, respectively). Additionally, using 0.1 as the rule-out cut-off of FNI, the sensitivity was 0.99 and the positive predictive value was 0.19. Both duration of diabetes and A1c did not impact FNI performance. In sum, FNI is a valuable score for predicting fibrotic nonalcoholic steatohepatitis not only for primary care units but also for diabetes specialized care.

INTRODUCTION:The increasing burden of diabetes poses a great challenge to healthcare systems and economy worldwide. Although modern therapeutic strategies for diabetes are widely available, most patients still fail to achieve optimal clinical targets and well-being. The primary objective of this study was to assess and explore potential drivers and successful management of diabetes among people with diabetes, family members and healthcare professionals in Portugal, by applying the protocol of the multinational study "Diabetes, Attitudes, Wishes and Needs (DAWN2)".MATERIAL AND METHODS:A total of 767 adults, including 417 people with diabetes, 123 family members and 227 healthcare professionals, participated in the study. Surveys assessed health-related quality of life, self-management, attitudes/beliefs, social support and priorities for improvement areas in diabetes care.RESULTS:Diabetes has a negative impact on the physical health and emotional well-being of patients in Portugal and is also a psychological burden for family members. Earlier diagnosis and treatment of diabetes were mentioned as a major area of improvement. Healthcare professionals indicated the need for diabetes self-management education.CONCLUSION:We have used for the first time in Portugal the DAWN2 protocol to address the wishes, needs, and attitudes of Portuguese diabetes patients, their relatives, and healthcare professionals regarding the disease.

Aims/hypothesis Imbalances in glucose metabolism are hallmarks of clinically silent prediabetes (defined as impaired fasting glucose and/or impaired glucose tolerance) representing dysmetabolism trajectories leading to type 2 diabetes. CD26/dipeptidyl peptidase 4 (DPP4) is a clinically proven molecular target of diabetes-controlling drugs but the DPP4 gene control of dysglycaemia is not proven. Methods We dissected the genetic control of post-OGTT and insulin release responses by the DPP4 gene in a Portuguese population-based cohort of mainly European ancestry that comprised individuals with normoglycaemia and prediabetes, and in mouse experimental models of Dpp4 deficiency and hyperenergetic diet. Results In individuals with normoglycaemia, DPP4 single-nucleotide variants governed glycaemic excursions (rs4664446, p =1.63x10 −7 ) and C-peptide release responses (rs2300757, p =6.86x10 −5 ) upon OGTT. Association with blood glucose levels was stronger at 30 min OGTT, but a higher association with the genetic control of insulin secretion was detected in later phases of the post-OGTT response, suggesting that the DPP4 gene directly senses glucose challenges. Accordingly, in mice fed a normal chow diet but not a high-fat diet, we found that, under OGTT, expression of Dpp4 is strongly downregulated at 30 min in the mouse liver. Strikingly, no genetic association was found in prediabetic individuals, indicating that post-OGTT control by DPP4 is abrogated in prediabetes. Furthermore, Dpp4 KO mice provided concordant evidence that Dpp4 modulates post-OGTT C-peptide release in normoglycaemic but not dysmetabolic states. Conclusions/interpretation These results showed the DPP4 gene as a strong determinant of post-OGTT levels via glucose-sensing mechanisms that are abrogated in prediabetes. We propose that impairments in DPP4 control of post-OGTT insulin responses are part of molecular mechanisms underlying early metabolic disturbances associated with type 2 diabetes. Graphical abstract

Aims This study aims to estimate the associations between area-level deprivation and individual-level socio-economic factors, as well as their interaction, with glycated haemoglobin (HbA(1c)) levels. Methods We conducted a gamma multilevel regression analysis using individual-level data from the Portuguese National Health Examination Survey and a deprivation index built through factor analysis, at municipality level, with census variables. Results Living in a municipality with high material deprivation and having a low level of education were independently associated with an increase of 2.3% (95% confidence interval [CI] 0.6, 4.0) and of 1.6% (95% CI 0.6, 2.7) in the mean levels of HbA(1c), respectively. The interaction between area material deprivation and individual-level education was not associated with the levels of HbA(1c) (0.5%, 95% CI -1.3, 2.3). Conclusions Our findings support the collective resources model that argues that people in less deprived areas have better health because there are more collective resources. The results suggest that to reduce socio-economic inequalities associated with the levels of HbA(1c) and, consequently, with diabetes, will require attention to the area material deprivation and individual-level education. Upstream social determinants of health are thus highlighted.

ABSTRACTAims/hypothesisImbalances in glucose metabolism are hallmarks of clinically silent prediabetes representing dysmetabolism trajectories leading to type 2 diabetes (T2D). CD26/DPP4 is a clinically proven molecular target of diabetes-controlling drugs but the CD26 gene control of disglycemia is unsettled.MethodsWe dissected the genetic control of postprandial glycemic and insulin release responses by the CD26/DPP4 gene in an European/Portuguese population-based cohort that comprised individuals with normoglycemia and prediabetes, and in mouse experimental models of CD26 deficiency and hypercaloric diet.ResultsIn individuals with normoglycemia, CD26/DPP4 single-nucleotide variants governed glycemic excursions (rs4664446, P=1.63×10−7) and C-peptide release responses (rs2300757, P=6.86×10−5) upon OGTT. Association with glycemia was stronger at 30min OGTT but the higher association of the genetic control of insulin secretion was detected in later phases of the postprandial response suggesting that CD26/DDP4 gene directly senses glucose challenges. Accordingly, in mice fed normal chow diet but not high fat diet, we found that under OGTT expression of CD26/DPP4 gene is strongly down-regulated at 30min in the mouse liver. Strikingly, no genetic association was found in prediabetic individuals indicating that postprandial glycemic control by CD26/DPP4 is abrogated in prediabetes. Furthermore, CD26 null mice provided concordant evidence that CD26/DPP4 modulates postprandial C-peptide release in normoglycemic but not in dysmetabolic states.Conclusions/interpretationThese results unveiled CD26/DPP4 gene as a strong determinant of postprandial glycemia via glucose sensing mechanisms that are abrogated in prediabetes. We propose that impairments in CD26/DDP4 control of postprandial glucose-insulin responses are part of molecular mechanisms underlying early metabolic disturbances associated with T2D.RESEARCH IN CONTEXTWhat is already known about this subject?CD26/DPP4 is a clinically proven molecular target of diabetes-controlling drugsDPP4 enzymatic activity impacts in glycemia by degrading incretinsDPP4 represents a potential link between dysmetabolism and insulin resistance.What is the key question?Is CD26/DPP4 controlling postprandial glycemic and pancreatic responses?What are the new findings?Functional link between postprandial glycemia excursions and subsequent insulin release is operational in NGT individuals but is altered in prediabetes.CD26/DPP4 gene is a robust component of mechanisms that control postprandial glycemia excursions and insulin secretion in NGT individuals.CD26/DPP4 gene controls postprandial glucose-insulin responses via glucose sensing mechanisms that are abrogated in prediabetes.Postprandial reduction of hepatic CD26/DPP4 gene expression is abrogated in experimental diet-induced dysglycemia.CD26/DPP4 gene action in reducing post-prandial insulin release is not operating in experimental diet-induced dysglycemia.How might this impact on clinical practice in the foreseeable future?Impairments in the control of postprandial glucose-insulin responses by CD26/DDP4 are indicators of early metabolic disturbances and possible predictors of dysmetabolic trajectories leading to T2D.

Background and aims: Blinded retrospective continuous glucose monitoring (rCGM) provides detailed information about real-life glycaemic profile. In persons with type 2 diabetes without adequate glycaemic control, the structured introduction of rCGM may be beneficial to sustain improvements in diabetes management. Methods and results: 102 individuals with insulin-treated type 2 diabetes, age less than 66 years old and HbA1c >7.5%, were recruited. Participants performed a 7-day blinded rCGM (iPro2) every four months for one year. Biochemical, anthropometric, and rCGM data was collected. Partici-pants' and healthcare professionals' perceptions were assessed. 90 participants completed the protocol. HbA1c was 9.1 +/- 0.1% one year prior to enrolment and 9.4 +/- 0.1% at enrolment (p < 0.01). With the rCGM-based intervention, a decrease in HbA1c was achieved at 4 months (8.4 +/- 0.1%, p < 0.0001), and 12 months (8.1 +/- 0.1%, p < 0.0001). A signif-icant increase in time-in-range was observed (50.8 +/- 2.4 at baseline vs 61.5 +/- 2.2% at 12 months, for 70-180 mg/dL, p < 0.001), with no difference in exposure time to hypoglycaemia. After 12 months, there was an increase in self-reported diabetes treatment satisfaction (p < 0.05). Conclusion: In persons with type 2 diabetes and poor metabolic control, specific data from blinded rCGM informed therapeutic changes and referral to targeted education consultations on nutrition and insulin administration technique. Therapeutic changes were made more frequently and targeted to changes in medication dose, timing, and/or type, as well as to lifestyle. Together, these brought significant improvements in clinical outcomes, effective shared decision-making, and satisfaction with treatment. Registration number: NCT04141111. (c) 2021 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND li-cense (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Dietary fructose overshadows glucose in promoting metabolic complications. Intestinal fructose metabolism (IFM) protects against these effects in rodents, by favoring gluconeogenesis, but the extent of IFM in humans is not known. We therefore aimed to infer the extent of IFM by comparing the contribution of dietary fructose to systemic glucose and hepatic glycogen appearance postprandially. Twelve fasting healthy subjects ingested two protein meals in random order, one supplemented with 50 g 5/95 fructose/glucose (LF) and the other with 50 g 55/45 fructose/glucose (HF). Sources of postprandial plasma glucose appearance and hepatic glycogen synthesis were determined with deuterated water. Plasma glucose excursions, as well as pre- and post-meal insulin, c-peptide, and triglyceride levels were nearly identical for both meals. The total gluconeogenic contribution to plasma glucose appearance was significantly higher for HF versus LF (65 ± 2% vs. 34 ± 3%, p < 0.001). For HF, Krebs cycle anaplerosis accounted for two-thirds of total gluconeogenesis (43 ± 2%) with one-third from Triose-P sources (22 ± 1%). With LF, three-quarters of the total gluconeogenic contribution originated via Krebs cycle anaplerosis (26 ± 2%) with one-quarter from Triose-P sources (9 ± 2%). HF and LF gave similar direct and indirect pathway contributions to hepatic glycogen synthesis. Increasing the fructose/glucose ratio had significant effects on glucose appearance sources but no effects on hepatic glycogen synthesis sources, consistent with extensive IFM. The majority of fructose carbons were converted to glucose via the Krebs cycle.

Systemic insulin availability is determined by a balance between beta-cell secretion capacity and insulin clearance (IC). Insulin-degrading enzyme (IDE) is involved in the intracellular mechanisms underlying IC. The liver is a major player in IC control yet the role of hepatic IDE in glucose and lipid homeostasis remains unexplored. We hypothesized that IDE governs postprandial IC and hepatic IDE dysfunction amplifies dysmetabolic responses and prediabetes traits such as hepatic steatosis. In a European/Portuguese population-based cohort, IDE SNPs were strongly associated with postprandial IC in normoglycemic men but to a considerably lesser extent in women or in subjects with prediabetes. Liver-specific knockout-mice (LS-IDE KO) under normal chow diet (NCD), showed reduced postprandial IC with glucose intolerance and under high fat diet (HFD) were more susceptible to hepatic steatosis than control mice. This suggests that regulation of IC by IDE contributes to liver metabolic resilience. In agreement, LS-IDE KO hepatocytes revealed reduction of Glut2 expression levels with consequent impairment of glucose uptake and upregulation of CD36, a major hepatic free fatty acid transporter. Together these findings provide strong evidence that dysfunctional IC due to abnormal IDE regulation directly impairs postprandial hepatic glucose disposal and increases susceptibility to dysmetabolic conditions in the setting of Western diet/lifestyle.

Background: Hypoglycaemias represent a frequent acute complication in people with type 2 diabetes on insulin regimens, potentiated by symptoms, associated complications and quality of life reduction. Additionally, frequent episodes and inadequate treatment contribute to a gradual reduction of the ability to perceive hypos. Objective: To identify the occurrence of perceived and unperceived hypoglycaemias in persons with type 2 diabetes on insulin, especially through the use of a continuous glucose monitoring system (CGMS) device, the possible causes for the perceived episodes, and followed treatment. Methods People with type 2 diabetes used CGMS during 7 days, filling in data related with hypoglycaemias occurrence, including recorded glycaemia values, symptoms, estimated causes treatment and the need to get help from others. Results: The participating people with type 2 diabetes (n=60) had a mean age of 60.8±0.9 years, and a mean HbA1c of 7.5±0.1% (58 mmol/mol). One third of the participants reported hypoglycaemia symptoms, identifying 42 situations. 57% of those were confirmed by capillary glucose measurement, 17% were related only with symptoms, and 26% were pseudo-hypoglycaemias. Regarding these documented hypoglycaemias, the most common symptoms were: tremors (63%), visual difficulties (33%), perspiration (29%), hunger (17%), and heat (17%). On the other hand, 45% of participants had 89 episodes of non-perceived hypoglycaemias, of which 15% were of level 2 (≤54mg/dl). We identified non-perceived hypoglycaemias in both people who reported hypoglycaemia symptoms (56%) and people who didn´t report hypoglycaemia symptoms (40%). The causes reported by participants were related with intense or unexpected physical activity (23%), delay between meals (8%), less carbohydrate ingestion at last meal (8%), and excess of insulin administration (8%). Participants were not able to identify any cause in 42% of hypoglycaemia episodes. Taking into account hypoglycaemia therapeutic guidelines, we observed that only 50% were treated accordingly to recommendations (namely, glucose ingestion). Conclusion: A considerable proportion of non-perceived hypoglycaemias was uncovered through the CGMS, in people with type 2 diabetes on insulin, with or without perceived hypoglycaemias. Furthermore, half of the situations where the hypoglycaemia episode was symptomatic were treated in a less than adequate way. Funding Information: This research was supported by the Portuguese NovoNordisk. Declaration of Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Ethics Approval Statement: Ethical and regulatory approvals were obtained from the local Ethics Committee at APDP (117/2017).