The effect of bolus advisors on glycaemic parameters in adults with diabetes on intensive insulin therapy: A systematic review with meta-analysis

AIM

To conduct a systematic review with meta-analysis to provide a comprehensive synthesis of randomized controlled trials (RCTs) and prospective cohort studies investigating the effects of currently available bolus advisors on glycaemic parameters in adults with diabetes.

MATERIALS AND METHODS

An electronic search of PubMed, Embase, CINAHL, Cochrane Library and ClinicalTrials.gov was conducted in December 2022. The risk of bias was assessed using the revised Cochrane Risk of Bias tool. (Standardized) mean difference (MD) was selected to determine the difference in continuous outcomes between the groups. A random-effects model meta-analysis and meta-regression were performed. This systematic review was registered on PROSPERO (CRD42022374588).

RESULTS

A total of 18 RCTs involving 1645 adults (50% females) with a median glycated haemoglobin (HbA1c) concentration of 8.45% (7.95%-9.30%) were included. The majority of participants had type 1 diabetes (N = 1510, 92%) and were on multiple daily injections (N = 1173, 71%). Twelve of the 18 trials had low risk of bias. The meta-analysis of 10 studies with available data on HbA1c showed that the use of a bolus advisor modestly reduced HbA1c compared to standard treatment (MD -011%, 95% confidence interval -0.22 to -0.01; I2 = 0%). This effect was accompanied by small improvements in low blood glucose index and treatment satisfaction, but not with reductions in hypoglycaemic events or changes in other secondary outcomes.

CONCLUSION

Use of a bolus advisor is associated with slightly better glucose control and treatment satisfaction in people with diabetes on intensive insulin treatment. Future studies should investigate whether personalizing bolus advisors using artificial intelligence technology can enhance these effects.

An Insulin-Chromogranin A Hybrid Peptide Activates DR11-Restricted T Cells in Human Type 1 Diabetes

Hybrid insulin peptides (HIPs) formed through covalent cross-linking of proinsulin fragments to secretory granule peptides are detectable within murine and human islets. The 2.5HIP (C-peptide-chromogranin A [CgA] HIP), recognized by the diabetogenic BDC-2.5 clone, is a major autoantigen in the nonobese diabetic mouse. However, the relevance of this epitope in human disease is currently unclear. A recent study probed T-cell reactivity toward HIPs in patients with type 1 diabetes, documenting responses in one-third of the patients and isolating several HIP-reactive T-cell clones. In this study, we isolated a novel T-cell clone and showed that it responds vigorously to the human equivalent of the 2.5HIP (designated HIP9). Although the responding patient carried the risk-associated DRB1*04:01/DQ8 haplotype, the response was restricted by DRB1*11:03 (DR11). HLA class II tetramer staining revealed higher frequencies of HIP9-reactive T cells in individuals with diabetes than in control participants. Furthermore, in DR11+ participants carrying the DRB4 allele, HIP9-reactive T-cell frequencies were higher than observed frequencies for the immunodominant proinsulin 9-28 epitope. Finally, there was a negative correlation between HIP9-reactive T-cell frequency and age at diagnosis. These results provide direct evidence that this C-peptide-CgA HIP is relevant in human type 1 diabetes and suggest a mechanism by which nonrisk HLA haplotypes may contribute to the development of β-cell autoimmunity.

ARTICLE HIGHLIGHTS

Association Between Type 1 Diabetes Mellitus and Eating Disorders: A Systematic Review and Meta-Analysis

BACKGROUND

Previous meta-analyses have shown mixed results regarding the association between eating disorders (EDs) and type 1 diabetes mellitus (T1DM). Our paper aimed to analyse different EDs and disordered eating behaviours that may be practiced by patients with T1DM.

METHODS

A literature search of PubMed, Scopus and Web of Science was conducted on 17 January 2023, using the key terms "T1DM," "Eating Disorders" and "Bulimia." Only observational controlled studies were included. The Revman software (version 5.4) was used for the analysis.

RESULTS

T1DM was associated with increased risk of ED compared with nondiabetic individuals (RR = 2.47, 95% CI = 1.84-3.32, p-value < 0.00001), especially bulimia nervosa (RR = 2.80, 95% CI = 1.18-6.65, p-value = 0.02) and binge eating (RR = 1.53, 95% CI = 1.18-1.98, p-value = 0.001). Our analysis has shown that increased risk of ED among T1DM persisted regardless of the questionnaire used to diagnose ED; DM-validated questionnaires (RR = 2.80, 95% CI = 1.91-4.12, p-value < 0.00001) and generic questionnaires (RR = 2.03, 95% CI = 1.27-3.23, p-value = 0.003). Prevalence of insulin omission/misuse was 10.3%; diabetic females demonstrated a significantly higher risk of insulin omission and insulin misuse than diabetic males.

CONCLUSION

Our study establishes a significant and clear connection between EDs and T1DM, particularly bulimia and binge eating, with T1DM. Moreover, female diabetics are at higher risk of insulin misuse/omission. Early proactive screening is essential and tailored; comprehensive interventions combining diabetes and ED components are recommended for this population, with referral to a specialised psychiatrist.

Exploring Factors That Influence Postexercise Glycemia in Youth With Type 1 Diabetes in the Real World: The Type 1 Diabetes Exercise Initiative Pediatric (T1DEXIP) Study

OBJECTIVE

To explore 24-h postexercise glycemia and hypoglycemia risk, data from the Type 1 Diabetes Exercise Initiative Pediatric (T1DEXIP) study were analyzed to examine factors that may influence glycemia.

RESEARCH DESIGN AND METHODS

This was a real-world observational study with participant self-reported physical activity, food intake, and insulin dosing (multiple daily injection users). Heart rate, continuous glucose data, and available pump data were collected.

RESULTS

A total of 251 adolescents (42% females), with a mean ± SD age of 14 ± 2 years, and hemoglobin A1c (HbA1c) of 7.1 ± 1.3% (54 ± 14.2 mmol/mol), recorded 3,319 activities over ∼10 days. Trends for lower mean glucose after exercise were observed in those with shorter disease duration and lower HbA1c; no difference by insulin delivery modality was identified. Larger glucose drops during exercise were associated with lower postexercise mean glucose levels, immediately after activity (P < 0.001) and 12 to <16 h later (P = 0.02). Hypoglycemia occurred on 14% of nights following exercise versus 12% after sedentary days. On nights following exercise, more hypoglycemia occurred when average total activity was ≥60 min/day (17% vs. 8% of nights, P = 0.01) and on days with longer individual exercise sessions. Higher nocturnal hypoglycemia rates were also observed in those with longer disease duration, lower HbA1c, conventional pump use, and if time below range was ≥4% in the previous 24 h.

CONCLUSIONS

In this large real-world pediatric exercise study, nocturnal hypoglycemia was higher on nights when average activity duration was higher. Characterizing both participant- and event-level factors that impact glucose in the postexercise recovery period may support development of new guidelines, decision support tools, and refine insulin delivery algorithms to better support exercise in youth with diabetes.

Exploring the Pathophysiology of ATP-Dependent Potassium Channels in Insulin Resistance

Ionic channels are present in eucaryotic plasma and intracellular membranes. They coordinate and control several functions. Potassium channels belong to the most diverse family of ionic channels that includes ATP-dependent potassium (KATP) channels in the potassium rectifier channel subfamily. These channels were initially described in heart muscle and then in other tissues such as pancreatic, skeletal muscle, brain, and vascular and non-vascular smooth muscle tissues. In pancreatic beta cells, KATP channels are primarily responsible for maintaining the membrane potential and for depolarization-mediated insulin release, and their decreased density and activity may be related to insulin resistance. KATP channels' relationship with insulin resistance is beginning to be explored in extra-pancreatic beta tissues like the skeletal muscle, where KATP channels are involved in insulin-dependent glucose recapture and their activation may lead to insulin resistance. In adipose tissues, KATP channels containing Kir6.2 protein subunits could be related to the increase in free fatty acids and insulin resistance; therefore, pathological processes that promote prolonged adipocyte KATP channel inhibition might lead to obesity due to insulin resistance. In the central nervous system, KATP channel activation can regulate peripheric glycemia and lead to brain insulin resistance, an early peripheral alteration that can lead to the development of pathologies such as obesity and Type 2 Diabetes Mellitus (T2DM). In this review, we aim to discuss the characteristics of KATP channels, their relationship with clinical disorders, and their mechanisms and potential associations with peripheral and central insulin resistance.

The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes

Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.

The Discovery of New Inhibitors of Insulin-Regulated Aminopeptidase by a High-Throughput Screening of 400,000 Drug-like Compounds

With the ambition to identify novel chemical starting points that can be further optimized into small drug-like inhibitors of insulin-regulated aminopeptidase (IRAP) and serve as potential future cognitive enhancers in the clinic, we conducted an ultra-high-throughput screening campaign of a chemically diverse compound library of approximately 400,000 drug-like small molecules. Three biochemical and one biophysical assays were developed to enable large-scale screening and hit triaging. The screening funnel, designed to be compatible with high-density microplates, was established with two enzyme inhibition assays employing either fluorescent or absorbance readouts. As IRAP is a zinc-dependent enzyme, the remaining active compounds were further evaluated in the primary assay, albeit with the addition of zinc ions. Rescreening with zinc confirmed the inhibitory activity for most compounds, emphasizing a zinc-independent mechanism of action. Additionally, target engagement was confirmed using a complementary biophysical thermal shift assay where compounds causing positive/negative thermal shifts were considered genuine binders. Triaging based on biochemical activity, target engagement, and drug-likeness resulted in the selection of 50 qualified hits, of which the IC50 of 32 compounds was below 3.5 µM. Despite hydroxamic acid dominance, diverse chemotypes with biochemical activity and target engagement were discovered, including non-hydroxamic acid compounds. The most potent compound (QHL1) was resynthesized with a confirmed inhibitory IC50 of 320 nM. Amongst these compounds, 20 new compound structure classes were identified, providing many new starting points for the development of unique IRAP inhibitors. Detailed characterization and optimization of lead compounds, considering both hydroxamic acids and other diverse structures, are in progress for further exploration.

Investigating the Effects of Diet-Induced Prediabetes on Skeletal Muscle Strength in Male Sprague Dawley Rats

Type 2 diabetes mellitus, a condition preceded by prediabetes, is documented to compromise skeletal muscle health, consequently affecting skeletal muscle structure, strength, and glucose homeostasis. A disturbance in skeletal muscle functional capacity has been demonstrated to induce insulin resistance and hyperglycemia. However, the modifications in skeletal muscle function in the prediabetic state are not well elucidated. Hence, this study investigated the effects of diet-induced prediabetes on skeletal muscle strength in a prediabetic model. Male Sprague Dawley rats were randomly assigned to one of the two groups (n = 6 per group; six prediabetic (PD) and six non-pre-diabetic (NPD)). The PD group (n = 6) was induced with prediabetes for 20 weeks. The diet that was used to induce prediabetes consisted of fats (30% Kcal/g), proteins (15% Kcal/g), and carbohydrates (55% Kcal/g). In addition to the diet, the experimental animals (n = 6) were supplied with drinking water that was supplemented with 15% fructose. The control group (n = 6) was allowed access to normal rat chow, consisting of 35% carbohydrates, 30% protein, 15% fats, and 20% other components, as well as ordinary tap water. At the end of week 20, the experimental animals were diagnosed with prediabetes using the American Diabetes Association (ADA) prediabetes impaired fasting blood glucose criteria (5.6-6.9 mmol/L). Upon prediabetes diagnosis, the animals were subjected to a four-limb grip strength test to assess skeletal muscle strength at week 20. After the grip strength test was conducted, the animals were euthanized for blood and tissue collection to analyze glycated hemoglobin (HbA1c), plasma insulin, and insulin resistance using the homeostatic model of insulin resistance (HOMA-IR) index and malondialdehyde (MDA) concentration. Correlation analysis was performed to examine the associations of skeletal muscle strength with HOMA-IR, plasma glucose, HbA1c, and MDA concentration. The results demonstrated increased HbA1c, FBG, insulin, HOMA-IR, and MDA concentrations in the PD group compared to the NPD group. Grip strength was reduced in the PD group compared to the NPD group. Grip strength was negatively correlated with HbA1c, plasma glucose, HOMA-IR, and MDA concentration in the PD group. These observations suggest that diet-induced prediabetes compromises muscle function, which may contribute to increased levels of sedentary behavior during prediabetes progression, and this may contribute to the development of hyperglycemia in T2DM.

Accuracy of intermittently scanned continuous glucose monitoring during caesarean delivery in pregnant women with insulin-treated diabetes

AIM

Continuous Glucose Monitoring (CGM) systems are not currently recommended to guide intrapartum glucose and insulin infusion, due to insufficient data. In this study, intrapartum accuracy of intermittently scanned CGM (isCGM), compared to simultaneously measured capillary glucose (CG), was evaluated.

METHODS

Paired isCGM (Freestyle Libre 2) - CG data during caesarean delivery in pregnant women with insulin-treated diabetes were prospectively collected. The isCGM accuracy was assessed by MARD and Clarke Error Grid analysis. Moreover, the impact on intrapartum management was evaluated.

RESULTS

Sixty-eight paired isCGM-CG data of 19 women were evaluated. The overallMARD was 9.28 %. All values were in A and B zones of Clarke Error Grid. Forty-six (68 %) isCGM-CG pairs were in the same glycemic range, meaning the same intrapartum management. All discordant data were identified by checking CG in case of isCGM above 110 mg/dL or less than 70 mg/dL [chi-square 21.76, p < 0.001]. At ROC curve, isCGM above 110 mg/dL was associated with 100 % sensitivity to discordant result at CG (AUC 0.859, p < 0.001).

CONCLUSION

The accuracy of isCGM during caesarean delivery was good, particularly for glucose values between 70 and 110 mg/dL, when CG confirmation could be safely avoided.

A Real-World Prospective Study of the Effectiveness and Safety of Automated Insulin Delivery Compared With Other Modalities of Type 1 Diabetes Treatment During Ramadan Intermittent Fasting

OBJECTIVE

To compare the fasting experience and glycemic control during Ramadan among people with type 1 diabetes (PWT1D) who use automated insulin delivery (AID) versus other modalities of treatment.

RESEARCH DESIGN AND METHODS

A total of 294 PWT1D who attempted fasting during Ramadan in 2022 were categorized on the basis of treatment modality into one of five groups: 1) AID (n = 62); 2) conventional pump + continuous glucose monitoring (CGM; n = 37); 3) pump + self-monitoring of blood glucose (SMBG; n = 8); 4) multiple daily injections (MDI) + CGM (n = 155); and 5) MDI + SMBG (n = 32). Predictors of fasting most days of Ramadan (i.e., breaking fast ≤2 days because of diabetes) were analyzed using uni- and multivariable logistic regression.

RESULTS

The median numbers of days when fasting was broken because of diabetes were 2, 5, 3, 3.5, and 2.5 for AID, conventional pump + CGM, MDI + CGM, pump + SMBG, and MDI + SMBG users, respectively (P = 0.047). Users of AID had a significantly greater time in range (TIR) and lower glycemia risk index, time below range, and time above range compared with users of conventional pumps and MDI (both P < 0.05). Likewise, 53% of AID users attained the double target of 1) breaking fast ≤2 days because of diabetes and 2) maintaining TIR ≥70% during Ramadan compared with only 3% of the conventional pump users and 44% of the MDI + CGM users (both P < 0.05). Compared with MDI + CGM users, AID users were twice as likely to complete fasting most days of Ramadan.

CONCLUSIONS

Use of AID is associated with the highest rates of fasting and best glycemic control during Ramadan fasting.

Clues to the Design of Aggregation-Resistant Insulin from Proline Scanning of Highly Amyloidogenic Peptides Derived from the N-Terminal Segment of the A-Chain

Insulin aggregation poses a significant problem in pharmacology and medicine as it occurs during prolonged storage of the hormone and in vivo at insulin injection sites. We have recently shown that dominant forces driving the self-assembly of insulin fibrils are likely to arise from intermolecular interactions involving the N-terminal segment of the A-chain (ACC1-13). Here, we study how proline substitutions within the pilot GIVEQ sequence of this fragment affect its propensity to aggregate in both neutral and acidic environments. In a reasonable agreement with in silico prediction based on the Cordax algorithm, proline substitutions at positions 3, 4, and 5 turn out to be very effective in preventing aggregation according to thioflavin T-fluorescence-based kinetic assay, infrared spectroscopy, and atomic force microscopy (AFM). Since the valine and glutamate side chains within this segment are strongly involved in the interactions with the insulin receptor, we have focused on the possible implications of the Q → P substitution for insulin's stability and interactions with the receptor. To this end, comparative molecular dynamics (MD) simulations of the Q5P mutant and wild-type insulin were carried out for both free and receptor-bound (site 1) monomers. The results point to a mild destabilization of the mutant vis à vis the wild-type monomer, as well as partial preservation of key contacts in the complex between Q5P insulin and the receptor. We discuss the implications of these findings in the context of the design of aggregation-resistant insulin analogues retaining hormonal activity.

Continuous Glucose Monitoring-Based Metrics and Hypoglycemia Duration in Insulin-Experienced Individuals With Long-standing Type 2 Diabetes Switched From a Daily Basal Insulin to Once-Weekly Insulin Icodec: Post Hoc Analysis of ONWARDS 2 and ONWARDS 4

OBJECTIVE

This post hoc analysis assessed continuous glucose monitoring (CGM)-based metrics and hypoglycemia duration with once-weekly insulin icodec versus once-daily basal insulin analogs in insulin-experienced individuals with long-standing type 2 diabetes from two 26-week phase 3a trials (ONWARDS 2 and ONWARDS 4).

RESEARCH DESIGN AND METHODS

Time in range (TIR) (3.9-10.0 mmol/L), time above range (TAR) (>10.0 mmol/L), and time below range (TBR) (<3.9 mmol/L and <3.0 mmol/L) were assessed during three CGM time periods (switch [weeks 0-4], end of treatment [weeks 22-26], and follow-up [weeks 27-31]) for icodec versus comparators (ONWARDS 2, insulin degludec [basal regimen]; ONWARDS 4, insulin glargine U100 [basal-bolus regimen]) using double-blind CGM data. CGM-derived hypoglycemic episode duration (<3.9 mmol/L) was assessed.

RESULTS

In both trials, there were no statistically significant differences in TIR, TAR, or TBR (<3.0 mmol/L) for icodec versus comparators across all time periods. In the end-of-treatment period, mean TIR was 63.1% (icodec) vs. 59.5% (degludec) in ONWARDS 2 and 66.9% (icodec) vs. 66.4% (glargine U100) in ONWARDS 4. Mean TBR <3.9 mmol/L and <3.0 mmol/L remained within recommended targets (<4% and <1%, respectively) across time periods and treatment arms. Hypoglycemic episode duration (<3.9 mmol/L) was comparable across time periods and treatment arms (median duration ≤40 min).

CONCLUSIONS

In insulin-experienced participants with long-standing type 2 diabetes, CGM-based TIR, TAR, and CGM-derived hypoglycemia duration (<3.9 mmol/L) were comparable for icodec and once-daily basal insulin analogs during all time periods. TBR remained within recommended targets.

β-Cell Function and Insulin Dynamics in Obese Patients With and Without Diabetes After Sleeve Gastrectomy

Improved β-cell function seems to be essential for better glucose homeostasis after Roux-en-Y gastric bypass but is less studied after sleeve gastrectomy (SG). We evaluated the effects of SG on β-cell function in obese patients with diabetes (DM group) and without (control group) in response to both oral and intravenous glucose stimulation. The DM group demonstrated impaired insulin sensitivity and insulin response to glucose before surgery. The insulin sensitivity index of both groups significantly improved after SG. In addition, the insulin response to glucose (early insulinogenic index in oral glucose tolerance test and acute insulin response to glucose in an intravenous glucose tolerance test) increased in the DM group but decreased in the control group. As a result, β-cell function improved significantly in both groups after SG since the disposition index (DI) increased in both. However, the DI of the DM group was not restored to the level of control group up to 1 year after SG. Our results support that obese patients, with and without diabetes, could benefit from SG in β-cell function. For obese patients at risk for or who have been diagnosed with diabetes, interventions should be recommended early to preserve or restore β-cell function, and SG could be an effective choice. Further studies are needed for long-term effects.

ARTICLE HIGHLIGHTS

Continuous Glucose Monitoring Systems in Noninsulin-Treated People with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Introduction: Continuous glucose monitoring (CGM) has shown favorable outcomes in patients with type 2 diabetes (T2D) who are on insulin therapy. However, the efficacy of CGM in managing glucose levels in noninsulin-treated people with T2D remains controversial. Methods: PubMed, Cochrane, and Embase were searched for randomized controlled trials (RCTs) comparing CGM to self-monitoring of blood glucose (SMBG) in people with T2D not using insulin. We computed weighted mean differences (WMDs) and standard mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CIs). Heterogeneity was assessed using I2 statistics. Statistical analyses were performed using R version 4.2.3. Results: We included six RCTs comprising 407 noninsulin-treated people with T2D of whom 228 were randomized to CGM. Diabetes duration ranged from 5.4 to 13.9 years. The mean age was 57.9 years and the mean body mass index was 30.8 kg/m2. Four trials used real-time CGM (rt-CGM) and two intermittent scanning CGM (is-CGM). Compared with SMBG, CGM significantly reduced the glycated hemoglobin level (WMD -0.31%; 95% CI -0.42 to -0.21; I2 = 0%), glucose level (WMD -11.16 mg/dL; 95% CI -19.94 to -2.39; I2 = 0%), time in hypoglycemia level 2 (WMD -0.28%; 95% CI -0.52 to -0.03; I2 = 91%), glucose time >180 mg/dL (WMD -7.75%; 95% CI -12.04 to -3.45; I2 = 0%), and the standard deviation of glucose variation (WMD -4.00 mg/dL; 95% CI -6.86 to -1.14; I2 = 0%). CGM also increased time in range (WMD 8.63%; 95% CI 4.54-12.71; I2 = 0%) and treatment satisfaction (SMD 0.79; 95% CI 0.54-1.05; I2 = 0%). Conclusion: In this meta-analysis, rt-CGM and is-CGM were associated with improvement in glycemic control in people with T2D not using insulin when compared to SMBG.

GPAT1 Activity and Abundant Palmitic Acid Impair Insulin Suppression of Hepatic Glucose Production in Primary Mouse Hepatocytes

BACKGROUND

Glycerol-3-phosphate acyltransferase (GPAT) activity is correlated with obesity and insulin resistance in mice and humans. However, insulin resistance exists in people with normal body weight, and individuals with obesity may be metabolically healthy, implying the presence of complex pathophysiologic mechanisms underpinning insulin resistance.

OBJECTIVE

We asked what conditions related to GPAT1 must be met concurrently for hepatic insulin resistance to occur.

METHODS

Mouse hepatocytes were overexpressed with GPATs via adenoviral infection or exposed to high or low concentrations of glucose. Glucose production by the cells and phosphatidic acid (PA) content in the cells were assayed, GPAT activity was measured, relative messenger RNA expressions of sterol-regulatory element-binding protein 1c (SREBP1c), carbohydrate response element-binding protein (ChREBP), and GPAT1 were analyzed, and insulin signaling transduction was examined.

RESULTS

Overexpressing GPAT1 in mouse hepatocytes impaired insulin's suppression of glucose production, together with an increase in both N-ethylmaleimide-resistant GPAT activity and the content of di-16:0 PA. Akt-mediated insulin signaling was inhibited in hepatocytes that overexpressed GPAT1. When the cells were exposed to high-glucose concentrations, insulin suppression of glucose production was impaired, and adding palmitic acid exacerbated this impairment. High-glucose exposure increased the expression of SREBP1c, ChREBP, and GPAT1 by ∼2-, 5-, and 5.7-fold, respectively. The addition of 200 mM palmitic acid or linoleic acid to the culture media did not change the upregulation of expression of these genes by high glucose. High-glucose exposure increased di-16:0 PA content in the cells, and adding palmitic acid further increased di-16:0 PA content. The effect was specific to palmitic acid because linoleic acid did not show these effects.

CONCLUSION

These data demonstrate that high-GPAT1 activity, whether induced by glucose exposure or acquired by transfection, and abundant palmitic acid can impair insulin's ability to suppress hepatic glucose production in primary mouse hepatocytes.

Docosahexaenoic and Eicosapentaenoic Acids Promote the Accumulation of Browning-Related Myokines via Calcium Signaling in Insulin-Resistant Mice

BACKGROUND

Myokines have a prominent effect on improving insulin resistance (IR) by inducing browning of white adipose tissue (WAT). Although docosahexaenoic acids (DHA) and eicosapentaenoic acids (EPA) play roles in improving IR and stimulating browning, whether they mediate myokines directly remains unknown.

OBJECTIVE

This study aims to investigate the effects of DHA and EPA on browning-related myokines under IR and clarify the mechanism via Ca2+ signaling.

METHODS

The expression and secretion levels of myokines in IR mice and IR myotubes were detected after DHA/EPA treatment. The crosstalk between myotubes and adipocytes was evaluated through a method in which IR adipocytes were treated with the culture medium supernatant of myotubes treated with DHA/EPA. The expression of browning markers in the WAT of IR mice and adipocytes was determined. A calcium chelator was used to determine whether DHA and EPA regulate myokine production through a calcium ion-dependent pathway.

RESULTS

In vivo experiments: 3:1 and 1:3 DHA/EPA promoted the mRNA levels of Irisin, IL-6, IL-15, and FGF21 in skeletal muscle, stimulated WAT browning, reduced lipid accumulation; 3:1 DHA/EPA upregulated the serum concentration of Irisin; 1:3 DHA/EPA upregulated the serum concentrations of Irisin, IL-6, and FGF21. In vitro experiments: the levels of Irisin and IL-6 in C2C12 myotubes and their medium supernatant were significantly elevated in the 3:1 and 1:3 groups and the upregulation of browning markers and reduction in fat accumulation were observed in adipocytes treated with the medium supernatant of C2C12 myotubes in the 3:1 and 1:3 groups. However, the above phenomena disappeared when Ca2+ signaling was inhibited.

CONCLUSIONS

Treatment with DHA and EPA at composition ratios of 3:1 and 1:3 induces browning of WAT in IR mice, which is likely related to the promotion of the accumulation of myokines, especially Irisin and IL-6, via Ca2+ signaling.

Landscape of pharmacogenetic variants associated with non-insulin antidiabetic drugs in the Indian population

INTRODUCTION

Genetic variants contribute to differential responses to non-insulin antidiabetic drugs (NIADs), and consequently to variable plasma glucose control. Optimal control of plasma glucose is paramount to minimizing type 2 diabetes-related long-term complications. India's distinct genetic architecture and its exploding burden of type 2 diabetes warrants a population-specific survey of NIAD-associated pharmacogenetic (PGx) variants. The recent availability of large-scale whole genomes from the Indian population provides a unique opportunity to generate a population-specific map of NIAD-associated PGx variants.

RESEARCH DESIGN AND METHODS

We mined 1029 Indian whole genomes for PGx variants, drug-drug interaction (DDI) and drug-drug-gene interactions (DDGI) associated with 44 NIADs. Population-wise allele frequencies were estimated and compared using Fisher's exact test.

RESULTS

Overall, we found 76 known and 52 predicted deleterious common PGx variants associated with response to type 2 diabetes therapy among Indians. We report remarkable interethnic differences in the relative cumulative counts of decreased and increased response-associated alleles across NIAD classes. Indians and South Asians showed a significant excess of decreased metformin response-associated alleles compared with other global populations. Network analysis of shared PGx genes predicts high DDI risk during coadministration of NIADs with other metabolic disease drugs. We also predict an increased CYP2C19-mediated DDGI risk for CYP3A4/3A5-metabolized NIADs, saxagliptin, linagliptin and glyburide when coadministered with proton-pump inhibitors (PPIs).

CONCLUSIONS

Indians and South Asians have a distinct PGx profile for antidiabetes drugs, marked by an excess of poor treatment response-associated alleles for various NIAD classes. This suggests the possibility of a population-specific reduced drug response in atleast some NIADs. In addition, our findings provide an actionable resource for accelerating future diabetes PGx studies in Indians and South Asians and reconsidering NIAD dosing guidelines to ensure maximum efficacy and safety in the population.

A two-sample Mendelian randomization study explores metabolic profiling of different glycemic traits

We assessed the causal relation of four glycemic traits and type 2 diabetes liability with 167 metabolites using Mendelian randomization with various sensitivity analyses and a reverse Mendelian randomization analysis. We extracted instruments for fasting glucose, 2-h glucose, fasting insulin, and glycated hemoglobin from the Meta-Analyses of Glucose and Insulin-related traits Consortium (n = 200,622), and those for type 2 diabetes liability from a meta-analysis of multiple cohorts (148,726 cases, 965,732 controls) in Europeans. Outcome data were from summary statistics of 167 metabolites from the UK Biobank (n = 115,078). Fasting glucose and 2-h glucose were not associated with any metabolite. Higher glycated hemoglobin was associated with higher free cholesterol in small low-density lipoprotein. Type 2 diabetes liability and fasting insulin were inversely associated with apolipoprotein A1, total cholines, lipoprotein subfractions in high-density-lipoprotein and intermediate-density lipoproteins, and positively associated with aromatic amino acids. These findings indicate hyperglycemia-independent patterns and highlight the role of insulin in type 2 diabetes development. Further studies should evaluate these glycemic traits in type 2 diabetes diagnosis and clinical management.

Antidiabetic drug administration prevents bone mineral density loss: Evidence from a two-sample Mendelian randomization study

The aim of this study was to investigate the effect of common antidiabetic drugs on BMD by two-sample Mendelian randomization (MR). The single nucleotide polymorphisms that were strongly associated with insulin, metformin, rosiglitazone and gliclazide were extracted as instrumental variables (IVs) for MR analysis. The inverse variance weighted (IVW) method was used as the primary MR method to assess the causal effect of antidiabetic drugs on BMD, and other MR methods, including Weighted median, MR Egger and Weighted mode, were used for complementary analysis. Reliability and stability were assessed by the leave-one-out test. In the present work, IVW estimation of the causal effect of insulin on heel BMD demonstrated that there was a null effect of insulin on heel BMD (β = 0.765; se = 0.971; P = 0.430), while metformin treatment had a positive effect on heel BMD (β = 1.414; se = 0.460; P = 2.118*10-3). The causal relationship between rosiglitazone and heel BMD analysed by IVW suggested that there was a null effect of rosiglitazone on heel BMD (β = -0.526; se = 1.744; P = 0.763), but the causal effect of gliclazide on heel BMD evaluated by IVW demonstrated that there was a positive effect of gliclazide on heel BMD (β = 2.671; se = 1.340; P = 0.046). In summary, the present work showed that metformin and gliclazide have a role in reducing BMD loss in patients with diabetes and are recommended for BMD loss prevention in diabetes.

Self-care activities in pediatric patients with type 1 diabetes mellitus

INTRODUCTION

Effective diabetes self-management and collaborative responsibility sharing with parents are imperative for pediatric patients with type 1 diabetes mellitus, particularly as they gradually assume more self-care responsibilities. The primary goal of this study was to assess differences in adherence to self-care activities regarding sociodemographics and clinical characteristics in pediatric patients with type 1 diabetes. The secondary goal of this study was to understand the level of parental involvement in diabetes management and to assess the pediatric patients' behaviors (independent or dependent on disease self-management) that relate to sociodemographic and clinical characteristics.

METHODS

This was a comparative cross-sectional and correlational study. The study sample included 182 children and adolescents who had been diagnosed with type 1 diabetes at least 3 months prior. Data collection instruments included a sociodemographic and questionnaire about Adherence to self-care activities and parental involvement in diabetes self-management, as well as a documentation sheet for recording clinical data.

RESULTS

A majority of participants (71%) exhibited non-adherence to self-care tasks, despite 78.0% asserting their independence in diabetes self-management. Notably, insufficient parental involvement in administering insulin therapy significantly predicted severe hypoglycemic episodes.

CONCLUSIONS

Pediatric patients dealing with type 1 diabetes demonstrate a substantial degree of autonomy in managing their condition, paradoxically coupled with self-reported non-adherence to critical self-care responsibilities. Notably, children (aged 8-12) rely more heavily on parental support, especially concerning insulin therapy administration. The study underscores the crucial role of parental engagement in insulin therapy, as its deficiency significantly predicts the likelihood of severe hypoglycemic episodes.

Omentin associates with serum metabolite profiles indicating lower diabetes risk: KORA F4 Study

INTRODUCTION

Circulating omentin levels have been positively associated with insulin sensitivity. Although a role for adiponectin in this relationship has been suggested, underlying mechanisms remain elusive. In order to reveal the relationship between omentin and systemic metabolism, this study aimed to investigate associations of serum concentrations of omentin and metabolites.

RESEARCH DESIGN AND METHODS

This study is based on 1124 participants aged 61-82 years from the population-based KORA (Cooperative Health Research in the Region of Augsburg) F4 Study, for whom both serum omentin levels and metabolite concentration profiles were available. Associations were assessed with five multivariable regression models, which were stepwise adjusted for multiple potential confounders, including age, sex, body mass index, waist-to-hip ratio, lifestyle markers (physical activity, smoking behavior and alcohol consumption), serum adiponectin levels, high-density lipoprotein cholesterol, use of lipid-lowering or anti-inflammatory medication, history of myocardial infarction and stroke, homeostasis model assessment 2 of insulin resistance, diabetes status, and use of oral glucose-lowering medication and insulin.

RESULTS

Omentin levels significantly associated with multiple metabolites including amino acids, acylcarnitines, and lipids (eg, sphingomyelins and phosphatidylcholines (PCs)). Positive associations for several PCs, such as diacyl (PC aa C32:1) and alkyl-alkyl (PC ae C32:2), were significant in models 1-4, whereas those with hydroxytetradecenoylcarnitine (C14:1-OH) were significant in all five models. Omentin concentrations were negatively associated with several metabolite ratios, such as the valine-to-PC ae C32:2 and the serine-to-PC ae C32:2 ratios in most models.

CONCLUSIONS

Our results suggest that omentin may influence insulin sensitivity and diabetes risk by changing systemic lipid metabolism, but further mechanistic studies investigating effects of omentin on metabolism of insulin-sensitive tissues are needed.

Estimated Sustainable Cost-Based Prices for Diabetes Medicines

Importance

The burden of diabetes is growing worldwide. The costs associated with diabetes put substantial pressure on patients and health budgets, especially in low- and middle-income countries. The prices of diabetes medicines are a key determinant for access, yet little is known about the association between manufacturing costs and current market prices.

Objectives

To estimate the cost of manufacturing insulins, sodium-glucose cotransporter 2 inhibitors (SGLT2Is), and glucagonlike peptide 1 agonists (GLP1As), derive sustainable cost-based prices (CBPs), and compare these with current market prices.

Design, Setting, and Participants

In this economic evaluation, the cost of manufacturing insulins, SGLT2Is, and GLP1As was modeled. Active pharmaceutical ingredient cost per unit (weighted least-squares regression model using data from a commercial database of trade shipments, data from January 1, 2016, to March 31, 2023) was combined with costs of formulation and other operating expenses, plus a profit margin with an allowance for tax, to estimate CBPs. Cost-based prices were compared with current prices in 13 countries, collected in January 2023 from public databases. Countries were selected to provide representation of different income levels and geographic regions based on the availability of public databases.

Main Outcomes and Measures

Estimated CBPs; lowest current market prices (2023 US dollars).

Results

In this economic evaluation of manufacturing costs, estimated CBPs for treatment with insulin in a reusable pen device could be as low as $96 (human insulin) or $111 (insulin analogues) per year for a basal-bolus regimen, $61 per year using twice-daily injections of mixed human insulin, and $50 (human insulin) or $72 (insulin analogues) per year for a once-daily basal insulin injection (for type 2 diabetes), including the cost of injection devices and needles. Cost-based prices ranged from $1.30 to $3.45 per month for SGLT2Is (except canagliflozin: $25.00-$46.79) and from $0.75 to $72.49 per month for GLP1As. These CBPs were substantially lower than current prices in the 13 countries surveyed.

Conclusions and Relevance

High prices limit access to newer diabetes medicines in many countries. The findings of this study suggest that robust generic and biosimilar competition could reduce prices to more affordable levels and enable expansion of diabetes treatment globally.

Efficacy of Semaglutide in Overweight and Obese Patients with Type 1 Diabetes

Introduction: More than two-thirds of patients with type 1 diabetes (T1D) are overweight (OW) and/or obese (OB) in the USA and Western Europe, resulting in insulin resistance as in type 2 diabetes. None of the currently available glucagon like polypeptide 1 (GLP-1) analogs are approved for patients with T1D. A higher dose of semaglutide has been approved by the Food and Drug Administration (FDA) for subjects with body mass index (BMI) >27 kg/m2. We evaluated the real-world use of semaglutide in patients with T1D. Methods: This was a retrospective chart review study of 50 OW or OB patients with T1D who were initiated on semaglutide and followed for 1 year. The control group comprised of 50 computer-matched patients (for sex, race, weight, BMI, and diabetes duration) during a similar time period and were not on any weight loss medications. Results: Most patients (92%) were non-Hispanic white in both arms. Mean ± standard deviation (SD) age and duration of diabetes were 42 ± 11 and 27 ± 12 years, respectively. The continuous glucose monitors (CGM), insulin pump use, baseline BMI and body weight were also similar in the two groups. Baseline glycosylated hemoglobin (HbA1c) was insignificantly lower in the semaglutide group (7.6% vs. 8.2%, respectively; P = non-significant [NS]). Total daily insulin dose (TDD) and insulin dose per kg body weight were higher in the semaglutide group at baseline with no difference in basal or prandial insulin dose. There were significantly greater declines in mean (±SD), BMI (7.9% ± 2.6%), body weight (15.9 lbs ± 5.4 lbs), HbA1c, CGM glucose SD and coefficient of variation (CV), and increase in CGM time in range (TIR) in the semaglutide group compared to the control group with no difference in insulin dose changes, time above range (TAR), or time below range (TBR). Conclusions: We conclude that use of semaglutide in patients who are OW and/or OB with T1D was effective in lowering body weight and BMI, and improving glycemic metrics in this pilot real-world study. We strongly recommend performing prospective, large-randomized clinical trials with newer GLP-1 analogs like semaglutide and tirzepatide (twin-cretin) for subjects with T1D associated with OW and/or OB.

Advances in Automated Insulin Delivery with the Medtronic 780G: The Australian Experience

Aim: To assess the real-world performance of MiniMed™ 780G for Australians with type 1 diabetes (T1D) following advanced hybrid closed loop (AHCL) activation and to evaluate the effect of changing from MiniMed 670/770G to 780G. Methods: We analyzed deidentified Carelink™ continuous glucose monitoring (CGM) data from Australian users from January 2020 to December 2022, including the proportion attaining three major consensus targets: Glucose management indicator (GMI <7.0%), time in range (TIR 70-180 mg/dL >70%), and time below range (TBR 70 mg/dL <4%). Results: Comparing 670/770G users (n = 5676) for mean ± standard deviation 364 ± 244 days with 780G users (n = 3566) for 146 ± 145 days, the latter achieved a higher TIR (72.6% ± 10.6% vs. 67.3% ± 11.4%; P < 0.001), lower time above range (TAR) (25.5% ± 10.9% vs. 30.6% ± 11.7%; P < 0.001), and lower GMI (6.9% ± 0.4% vs. 7.2% ± 0.4%; P < 0.001) without compromising TBR (1.9% ± 1.8% vs. 2.0% ± 1.8%; P = 0.0015). Of 1051 670/770G users transitioning to 780G, TIR increased (70.0% ± 10.7% to 74.0% ± 10.2%; P < 0.001), TAR decreased (28.1% ± 10.9% to 24.0% ± 10.7%; P < 0.001), and TBR was unchanged. The percentage of users attaining all three CGM targets was higher in 780G users (50.1% vs. 29.5%; P < 0.001). CGM metrics were stable at 12 months post-transition. Conclusion: Real-world data from Australia shows that a higher proportion of MiniMed 780G users meet clinical targets for CGM consensus metrics compared to MiniMed 670/770G users and glucose control was sustained over 12 months.

The Effectiveness of Superbolus on Postprandial Blood Glucose Management of Pregnant Women With Type 1 Diabetes

AIM

Pregnancies of women with pregestational diabetes are at risk of after-meal glucose peaks and late after-meal hypoglycemia, particularly at breakfast. We aimed to explore the effectiveness of a specific feature of insulin pump therapy called superbolus in preventing these glucose swings.

METHODS

In this retrospective observational study, we analyzed continuous glucose monitoring data of patients with type 1 diabetes in pregnancy who were advised to use superbolus to manage their breakfast. Some of the postprandial basal insulin delivery was partially reduced and delivered instead as additional insulin bolus on top of a normal bolus. Outcomes of interest were one hour after breakfast glucose levels, the time in glucose range for after breakfast period, the number of late hypoglycemic episodes.

RESULTS

Overall, 21 consecutive pregnant women with type 1 diabetes (mean age 34.3 ± 5.5 years, mean pregestational body mass index 23.7 ± 4.7 kg/m2, HbA1c levels during pregnancy 6.1 ± 0.6%) were studied. Superbolus reduced after breakfast glucose peaks (one hour after breakfast glucose levels 130 ± 17 mg/dL vs 123 ± 10 mg/dL before and after superbolus use, respectively, P = .01), improved the time in glucose range for after breakfast period (70.4% vs 50.8%, P = .001), and reduced the number of late hypoglycemic episodes (3 [1-5] vs 1 [0-2], P< .0001).

CONCLUSION

Superbolus was effective in avoiding after-meal glucose peaks, increased postprandial glucose time in target, without late hypoglycemia occurrence. It represents a valid option for the treatment of pregnant women with type 1 diabetes using insulin pump.

Association between frequency of self-monitoring of blood glucose and glycemic control in patients with type 2 diabetes

AIM

To determine the association between the frequency of self-monitoring of blood glucose (SMBG) and glycemic control in patients with type 2 diabetes.

METHODS

The retrospective study analyzed data from 3,630 patients with type 2 diabetes who were enrolled between August 2020 and July 2021. 2456 non-insulin-treated patients were divided into SMBG ≤ 6 times/week and > 6 times/week groups. 1174 insulin-treated patients were divided into SMBG ≤ 9 times/week and > 9 times/week groups. Propensity score matching was used to generate groups with well-balanced covariates. Primary outcomes were changes in fasting blood glucose (FBG) and postprandial blood glucose (PBG) from baseline to 6 months.

RESULTS

In the non-insulin-treated group, a comparison in FBG and PBG reduction between the SMBG > 6 times/week and ≤ 6 times/week groups was statistically significant (-0.59 vs. -0.18 mmol/l, P < 0.001; -0.91 vs. -0.36 mmol/l, P < 0.001). In the insulin-treated group, there was no statistically significant reduction in FBG or PBG, patients with baseline FBG > 8 or 9 mmol/l and SMBG > 9 times/week had a significant FBG reduction than the ≤ 9 times/week group.

CONCLUSION

Frequent SMBG was associated with better glycemic control in non-insulin-treated patients. Insulin-treated patients with poor glycemic control may benefit from frequent SMBG.

Insulin requirements during pregnancy in women with type 1 diabetes treated with insulin pump

INTRODUCTION

Insulin requirement in women with Type 1 diabetes (T1DM) changes throughout pregnancy. The aim of this study was to determine the total change in insulin requirements and the effect of gestational weight gain (GWG) and pre-gestational BMI on insulin requirements during pregnancy in women with T1DM treated with continuous subcutaneous insulin infusion and continuous glucose monitoring.

METHODS

This historical cohort study included all consecutive women with T1DM who were monitored during pregnancy at the high-risk pregnancy clinic at a tertiary medical center during April 2011-April 2019. One Way Repeated Measures ANOVA with Bonferroni adjustment was conducted to compare the effects of gestational age on insulin requirements and a Two Way Repeated Measures ANOVA was employed to test for the interaction between gestational age intervals and maternal BMI and GWG.

RESULTS

Data regarding insulin requirements of 185 pregnancies were included in the analyses. There was a significant effect of gestational age on total insulin (Wilks' Lambda = 0.34, F(6,14) = 4.52, p = 0.009), basal insulin (Wilks' Lambda = 0.41, F(6,14) = 3.30, p = 0.031) and bolus insulin (Wilks' Lambda = 0.43, F(6,14) = 3.02, p = 0.041). Total insulin/kg requirements increased by 5.5% from 13-20 weeks to 20-26 weeks, 19% from 20-26 weeks to 26-33 weeks, and 17.4% from 26 to 33 weeks to delivery (p for trend = 0.009). Overall, insulin requirements increased by 42.1% from conception to delivery (p < 0.01). There was no significant main effect of maternal BMI or GWG on insulin requirements.

CONCLUSIONS

There is a significant increase in insulin requirements per kg during pregnancy in women with T1DM who were treated with an insulin pump.

High Doses of Exogenous Glucagon Stimulate Insulin Secretion and Reduce Insulin Clearance in Healthy Humans

Glucagon is generally defined as a counterregulatory hormone with a primary role to raise blood glucose concentrations by increasing endogenous glucose production (EGP) in response to hypoglycemia. However, glucagon has long been known to stimulate insulin release, and recent preclinical findings have supported a paracrine action of glucagon directly on islet β-cells that augments their secretion. In mice, the insulinotropic effect of glucagon is glucose dependent and not present during basal euglycemia. To test the hypothesis that the relative effects of glucagon on hepatic and islet function also vary with blood glucose, a group of healthy subjects received glucagon (100 ng/kg) during fasting glycemia or experimental hyperglycemia (∼150 mg/dL) on 2 separate days. During fasting euglycemia, administration of glucagon caused blood glucose to rise due to increased EGP, with a delayed increase of insulin secretion. When given during experimental hyperglycemia, glucagon caused a rapid, threefold increase in insulin secretion, as well as a more gradual increase in EGP. Under both conditions, insulin clearance was decreased in response to glucagon infusion. The insulinotropic action of glucagon, which is proportional to the degree of blood glucose elevation, suggests distinct physiologic roles in the fasting and prandial states.

ARTICLE HIGHLIGHTS

Influence of sphingolipid enzymes on blood glucose levels, development of diabetes, and involvement of pericytes

AIMS

Sulfatide is a chaperone for insulin manufacturing in beta cells. Here we explore whether the blood glucose values normally could be associated with this sphingolipid and especially two of its building enzymes CERS2 and CERS6. Both T1D and T2D have low blood sulfatide levels, and insulin resistance on beta cells at clinical diagnosis. Furthermore, we examined islet pericytes for sulfatide, and beta-cell receptors for GLP-1, both of which are related to the insulin production.

MATERIALS AND METHODS

We examined mRNA levels in islets from the DiViD and nPOD studies, performed genetic association analyses, and histologically investigated pericytes in the islets for sulfatide.

RESULTS

Polymorphisms of the gene encoding the CERS6 enzyme responsible for synthesising dihydroceramide, a precursor to sulfatide, are associated with random blood glucose values in non-diabetic persons. This fits well with our finding of sulfatide in pericytes in the islets, which regulates the capillary blood flow in the islets of Langerhans, which is important for oxygen supply to insulin production. In the islets of newly diagnosed T1D patients, we observed low levels of GLP-1 receptors; this may explain the insulin resistance in their beta cells and their low insulin production. In T2D patients, we identified associated polymorphisms in both CERS2 and CERS6.

CONCLUSIONS

Here, we describe several polymorphisms in sulfatide enzymes related to blood glucose levels and HbA1c in non-diabetic individuals. Islet pericytes from such persons contain sulfatide. Furthermore, low insulin secretion in newly diagnosed T1D may be explained by beta-cell insulin resistance due to low levels of GLP-1 receptors.

Is It Time to Move Beyond TIR to TITR? Real-World Data from Over 20,000 Users of Continuous Glucose Monitoring in Patients with Type 1 and Type 2 Diabetes

The growing use of continuous glucose monitoring (CGM) has been supported by expert consensus and clinical guidelines on glycemic management in diabetes with time in range (TIR 70-180 mg/dL) representing a key CGM-derived glucose metric. Time in tight range (TITR) has also been proposed for clinical use, spanning largely normal glucose levels of 70-140 mg/dL. However, keeping such narrow glucose ranges can be challenging, and understanding the factors modulating TITR can help achieve these tight glycemic targets. Our real-life study aimed to evaluate the relationship between average glucose (AG) and TIR/TITR in a large cohort (n = 22,006) of CGM users, divided into four groups: self-identified as having type 1 diabetes (T1D) treated with insulin using multiple daily injections (MDI) or pumps; type 2 diabetes (T2D) on MDI or insulin pumps; T2D on basal insulin only; and T2D not on insulin treatment. The T2D groups, regardless of treatment type, displayed the highest TIR and TITR values, associated with lowest glycemic variability measured as glucose coefficient of variation (CV; 23-30%). The T1D group showed the lowest TIR and TITR, associated with the highest CVs (36-38%). Overall, higher CV was associated with lower TIR and TITR for AG values below 180 and 140 mg/dL, respectively, with the reverse holding true for AG values above these thresholds. The discordance between AG and TIR/TITR was less pronounced in T2D compared with T1D, attributed to lower CV in the former group. It was also observed that TITR has advantages over TIR for assessing glycemia status and progress toward more stringent A1C, particularly when approaching normal glucose levels. The data detail how CV affects the AG relationship with TIR/TITR, which has implications for CGM interpretation. In many instances TITR, rather than TIR, may be preferable to employ once AG falls below 140 mg/dL and near-normal glucose levels are required clinically.

Reduction in Postprandial Peak Glucose With Increased Technosphere Insulin Dosage

BACKGROUND

Technosphere Insulin (TI) is an ultra-rapid-acting inhaled insulin. This study assessed the mean peak two-hour postprandial glucose concentration with the initial TI dose (dose 1) calculated per the current label (United State Prescribing Information) compared with a ~2× higher dose (dose 2). Secondary objectives were to evaluate hypoglycemia within the two-hour postprandial period, evaluate change in forced expiratory volume in one second (FEV1) before and after the two-hour postprandial period, and monitor for other adverse events.

METHODS

Twenty patients with diabetes, on basal-bolus insulin therapy, received an initial dose 1 of TI followed by the higher dose 2, one to three days later. Subjects received an identical meal for both visits, and TI doses were administered immediately prior to the meal.

RESULTS

The higher dose 2 provided significant reductions in mean postprandial glucose excursion (PPGE) in the two-hour postprandial period starting from 45 minutes (P = .008) to 120 minutes (P < .0001). Mean peak glucose was reduced from 228.6 to 179.3 mg/dL (P < .001) at two hours. Two hypoglycemic events (one level 1, one level 2) were observed in a single subject during the two-hour postprandial period with dose 2. There were no significant changes in FEV1 after either dose of TI.

CONCLUSIONS

The higher dose 2 reduced PPGE versus the current label recommended dose 1 within the two-hour postprandial timeframe without any new safety concerns. When confirmed with a larger study, this higher TI dosing recommendation may help patients and clinicians minimize immediate postprandial hyperglycemia when titrating TI for prandial glucose control.

The association between antidepressant treatment and rates of insulin initiation in comorbid depression and type 2 diabetes: A UK electronic health record nested case-control study

AIMS

To investigate the association between antidepressant prescribing and the rate of insulin initiation in type 2 diabetes.

METHODS

Using UK primary care records we completed a nested-case control study in a individuals with comorbid depression and type 2 diabetes. Cases were defined as individuals initiating insulin, controls were individuals remaining on oral antidiabetic medication. We used conditional logistic regression to estimate incident rate ratios (IRR) and the 95% confidence intervals (CI) for the association between antidepressant prescribing and initiating insulin. We adjusted for demographic characteristics, comorbidities, health service and previous medication use.

RESULTS

We included 11,862 cases who initiated insulin, and 43,452 controls. Increased rates of insulin initiation were associated with any antidepressant prescription (IRR 3.78, 95% CI 3.53-4.04), longer (24+ months) durations of antidepressant treatment (IRR 5.61, 95% CI 5.23-6.03), and higher numbers (3+) of different antidepressant agents prescribed (IRR 5.72, 95% CI 5.25-6.24). There was no difference between recent and non-recent antidepressant prescriptions, or between different antidepressant agents.

CONCLUSIONS

Antidepressant prescribing was highly associated with the initiation of insulin therapy. However, this may not indicate a direct causal effect of the antidepressant medication itself, and may be a marker of more severe depression influencing diabetic control.

Diabetic Ketoacidosis at Onset of Type 1 Diabetes and Glycemic Outcomes with Closed-Loop Insulin Delivery

The presence of diabetic ketoacidosis (DKA) at diagnosis of type 1 diabetes (T1D) is associated with higher glycated hemoglobin levels over time. We evaluated whether hybrid-closed loop (HCL) therapy from onset of T1D could prevent the adverse impact of DKA at diagnosis on long-term glycemic outcomes. This was a posthoc analysis from 51 adolescents using HCL from diagnosis of T1D as part of the CLOuD trial (NCT02871089). We compared glycemic and insulin metrics between adolescents with (n = 17) and without (n = 34) DKA at diagnosis. Participants with and without DKA at diagnosis had similar time in target glucose range 3.9-10.0 mmol/L (70-180 mg/dL), time below range (<3.9 mmol/L, <70 mg/dL) and HbA1c at 6, 12, and 24 months. While insulin requirements at 6 months were higher in those with DKA at diagnosis, this was not statistically significant after adjusting for bodyweight. Residual C-peptide secretion was similar between groups. We conclude that HCL therapy may mitigate against the negative glycemic effects of DKA at T1D diagnosis.

Dapagliflozin ameliorated retinal vascular permeability in diabetic retinopathy rats by suppressing inflammatory factors

BACKGROUND

Diabetic retinopathy is a common microvascular complication of diabetes and one of the major causes of blindness in the working-age population. Emerging evidence has elucidated that inflammation drives the key mechanism of diabetes-mediated retinal disturbance. As a new therapeutic drug targeting diabetes, whether dapagliflozin could improve vascular permeability from the perspective of anti-inflammatory effect need to be further explored.

METHODS

Type 2 diabetic retinopathy rat model was established and confirmed by fundus fluorescein angiography (FFA). ELISA detected level of plasma inflammatory factors and C-peptide. HE staining, immunohistochemistry and western blot detected histopathology changes of retina, expression of retinal inflammatory factors and tight junction proteins.

RESULTS

Dapagliflozin exhibited hypoglycemic effect comparable to insulin, but did not affect body weight. By inhibiting expression of inflammatory factors (NLRP3, Caspase-1, IL-18, NF-κB) in diabetic retina and plasma, dapagliflozin reduced damage of retinal tight junction proteins and improved retinal vascular permeability. The anti-inflammatory effect of dapagliflozin was superior to insulin.

CONCLUSIONS

Dapagliflozin improved retinal vascular permeability by reducing diabetic retinal and plasma inflammatory factors. The anti-inflammatory mechanism of dapagliflozin is independent of hypoglycemic effect and superior to insulin.

Short- and Long-Term Effects on Glucose Control of Nonadherence to Insulin Therapy in People With Type 2 Diabetes An In Silico Study

BACKGROUND

Strict adherence to multiple daily insulin (MDI) therapy is a cornerstone for the achievement of good glucose control in people with advanced type 2 diabetes (T2D). Here, we aim to in silico assess glucose control in T2D subjects with poor adherence to MDI therapy.

METHODS

We tuned the Padova T2D Simulator, originally describing early-stage T2D physiology, around advanced T2D people. One hundred in silico advanced T2D subjects were generated and equipped with optimal MDI therapy: specifically, basal and bolus insulin amounts and injection times were individualized for each subject by applying titration algorithms that iteratively update insulin dose based on glucose deviation from its target. Then, the effect of nonadhering to MDI therapy was assessed using standard glucose control metrics calculated in two 6-month 3-meal/day in silico scenarios: in Scenario 1, subjects received the optimal basal and prandial insulin bolus at each meal; in Scenario 2, subjects received optimal basal insulin and randomly delayed or skipped the prandial insulin bolus in 3 lunches during working days and 1 dinner during weekends.

RESULTS

A statistically significant degradation was found in all glucose control outcome metrics in Scenario 2 versus Scenario 1: e.g., percent time above 180 mg/dL increased by 22.2% and glucose management index by 0.2%.

CONCLUSIONS

Impaired adherence to MDI therapy in T2D leads to glucose control deteriorations in both short and long terms. Interestingly, short-term hyperglycemia seems being contrasted by residual endogenous insulin secretion, which statistically increased by 3-fold after delayed/skipped insulin boluses compared with optimal ones.

Early Real-World Performance of the MiniMed™ 780G Advanced Hybrid Closed-Loop System and Recommended Settings Use in the United States

Background: The MiniMed™ 780G system (MM780G) with Guardian™ 4 sensor includes a 100 mg/dL glucose target (GT) and automated insulin corrections up to every 5 min and was recently approved for use in the United States. In the present study, early real-world MM780G performance and the use of recommended system settings (100 mg/dL GT with an active insulin time of 2 h), by individuals with type 1 diabetes, were evaluated. Methods: CareLink™ personal data uploaded between the launch of the MM780G to August 22, 2023 were aggregated and underwent retrospective analysis (based on user consent) and if users had ≥10 days of continuous glucose monitoring (CGM) data. The 24-h day CGM metrics, including mean glucose, percentage of time spent in (%TIR), above (%TAR), and below (%TBR) target range (70-180 mg/dL), in addition to delivered insulin and closed-loop (CL) exits, were compared between an overall group (n = 7499) and individuals who used recommended settings (each, for >95% of the time). An analysis of the same metrics for MiniMed™ 770G system (MM770G) users (n = 3851) who upgraded to the MM780G was also conducted (paired t-test or Wilcoxon signed-rank test, P < 0.05 considered statistically significant). Results: For MM780G users, CGM use, and time in CL were >90% and all MM780G CGM metrics exceeded consensus-recommended goals. With recommended settings (22% of all users), mean %TIR and %TITR (70-140 mg/dL) were 81.4% and 56.4%, respectively. For individuals who upgraded from the MM770G, %TIR and %TITR increased from 73.2% to 78.3% and 45.8% to 52.6%, respectively, while %TAR reduced from 25.1% to 20.2% (P < 0.001, for all three). CL exits/week averaged <1, for all MM780G users. Conclusions: Early real-world MM780G use in the United States demonstrated a high percentage of time in range with low time above and below range. These outcomes are similar to those observed for real-world MM780G use in other countries.

Glycated haemoglobin, HOMA2-B, C-peptide to glucose ratio and type 2 diabetes clusters as predictors for therapy failure in individuals with type 2 diabetes without insulin therapy: A registry analysis

AIM

Some people with type 2 diabetes mellitus (T2D) and declining β-cell function do require insulin over time. Various laboratory parameters, indices of glucose metabolism or phenotypes of T2D (clusters) have been suggested, which might predict future therapy failure (TF), indicating the need for insulin therapy initiation. This analysis evaluated glycated haemoglobin (HbA1c), homeostatic model assessment (HOMA)2-B, C-peptide to glucose ratio (CGR) and diabetes clusters as predictive parameters for the occurrence of glycaemic TF in individuals diagnosed with T2D without previous insulin therapy.

MATERIALS AND METHODS

In total, 159 individuals with T2D [41% female, median age 50 (IQR: 53-69) years, diabetes duration 9 (5-15) years], without insulin therapy were prospectively evaluated for the occurrence of a composite primary endpoint, including HbA1c increasing or remaining >8.0% (64 mmol/mol) 3 months after baseline on non-insulin glucose-lowering agents, insulin initiation or hospital admissions because of acute hyperglycaemic events. Diabetes clusters were formed according to previously described characteristics. Only severe autoimmune diabetes clusters were excluded because of a small amount of glutamate decarboxylase antibody-positive participants. The other clusters were distributed as mild age-related diabetes 33%; severe insulin-deficient diabetes 31%; mild obesity-related diabetes 20%; and severe insulin-resistant diabetes 15%.

RESULTS

During a median observation of 57 months, higher tertiles of HbA1c at baseline, HOMA2-B, as well as a lower CGR were significantly predictive for the occurrence of the primary endpoint. The probability of meeting the primary endpoint was the highest for mild obesity-related diabetes [hazard ratio 3.28 (95% confidence interval 1.75-6.2)], followed by severe insulin-deficient diabetes [hazard ratio 2.03 (95% confidence interval 1.1-3.7)], mild age-related diabetes and the lowest for severe insulin-resistant diabetes. The best performance to predict TF with an area under the curve (AUC) of 0.77 was HbA1c at baseline, followed by HOMA2-B (AUC 0.69) and CGR (AUC 0.64).

CONCLUSION

HbA1c, indices of insulin secretion capacity (HOMA2-B and CGR) and T2D clusters might be applicable tools to guide practitioners in the decision of whether insulin is required in people already diagnosed with T2D. These findings need to be validated in prospective studies.

Dual Tracer Test to Measure Tissue-Specific Insulin Action in Individual Mice Identifies In Vivo Insulin Resistance Without Fasting Hyperinsulinemia

The ability of metabolically active tissues to increase glucose uptake in response to insulin is critical to whole-body glucose homeostasis. This report describes the Dual Tracer Test, a robust method involving sequential retro-orbital injection of [14C]2-deoxyglucose ([14C]2DG) alone, followed 40 min later by injection of [3H]2DG with a maximal dose of insulin to quantify both basal and insulin-stimulated 2DG uptake in the same mouse. The collection of both basal and insulin-stimulated measures from a single animal is imperative for generating high-quality data since differences in insulin action may be misinterpreted mechanistically if basal glucose uptake is not accounted for. The approach was validated in a classic diet-induced model of insulin resistance and a novel transgenic mouse with reduced GLUT4 expression that, despite ubiquitous peripheral insulin resistance, did not exhibit fasting hyperinsulinemia. This suggests that reduced insulin-stimulated glucose disposal is not a primary contributor to chronic hyperinsulinemia. The Dual Tracer Test offers a technically simple assay that enables the study of insulin action in many tissues simultaneously. By administering two tracers and accounting for both basal and insulin-stimulated glucose transport, this assay halves the required sample size for studies in inbred mice and demonstrates increased statistical power to detect insulin resistance, relative to other established approaches, using a single tracer. The Dual Tracer Test is a valuable addition to the metabolic phenotyping toolbox.

ARTICLE HIGHLIGHTS

Outcomes associated with a variable rate insulin infusion diabetic ketoacidosis protocol

AIMS

To relate adverse events with glucose correction rates in diabetic ketoacidosis (DKA) using variable rate intravenous insulin-infusions (VRIII).

METHODS

Retrospective, observational study in adults with DKA who received insulin infusions between 2012 and 2017 at St Vincent's Hospital, Melbourne. Early correction of hyperglycaemia (<10 mmol/L) was evaluated for association with hypoglycaemia (<4.0 mmol/L), hypokalaemia (potassium <3.3 mmol/L) and clinical outcomes via regression analysis.

RESULTS

The study involved 97 patients, with 93 % having type 1 diabetes. The mean age was 38 years, 47 % were women and 35 % were admitted to intensive care. Hypoglycaemia rates during 12 and 24 h of treatment were 6.2 % and 8.2 %, respectively with 58 % of patients recording their first BGL <10 mmol/L within 12 h and 88 % within 24 h. Ketone clearance time averaged at 15.6 h. Hyperglycaemia correction rates to <10 mmol/L were not different in those with/without hypoglycaemia at 12/24 h, in multivariate analysis including admission BGL. Hypokalaemia occurred in 40.2 % of patients and was associated with lower pH but not BGL correction rates.

CONCLUSION

The VRIII protocol achieved early hyperglycaemia correction and ketoacidosis reversal with low hypoglycaemia risk. However, high hypokalaemia rates suggest the need for aggressive potassium replacement, especially in markedly acidotic patients.

Feasibility and Preliminary Safety of Smartphone-Based Automated Insulin Delivery in Adolescents and Children With Type 1 Diabetes

BACKGROUND

A smartphone-based automated insulin delivery (AID) controller device can facilitate use of interoperable components and acceptance in adolescents and children.

METHODS

Pediatric participants (N = 20, 8F) with type 1 diabetes were enrolled in three sequential age-based cohorts: adolescents (12-<18 years, n = 8, 5F), school-age (8-<12 years, n = 7, 2F), and young children (2-<8 years, n = 5, 1F). Participants used the interoperable artificial pancreas system (iAPS) and zone model predictive control (MPC) on an unlocked smartphone for 48 hours, consumed unrestricted meals of their choice, and engaged in various unannounced exercises. Primary outcomes and stopping criteria were defined using fingerstick blood glucose (BG) data; secondary outcomes compared continuous glucose monitoring (CGM) data with preceding sensor augmented pump (SAP) therapy.

RESULTS

During AID, there was no more than one BG <50 mg/dL except in one young child participant; no instance of more than two episodes of BG ≥300 mg/dL lasting longer than 2 hours; and no adverse events. Despite large meals (total of 404.9 grams of carbs) and unannounced exercise (total of 182 minutes), overall CGM percent time in range (TIR) of 70 to 180 mg/dL during AID was statistically similar to SAP (63.5% vs 57.3%, respectively, P = .145). Overnight glucose standard deviation was 43 mg/dL (vs SAP 57.9 mg/dL, P = .009) and coefficient of variation was 25.7% (vs SAP 34.9%, P < .001). The percent time in closed-loop mode and connected to the CGM was 92.7% and 99.6%, respectively. Surveys indicated that participants and parents/guardians were satisfied with the system.

CONCLUSIONS

The smartphone-based AID was feasible and safe in sequentially younger cohorts of adolescents and children.

CLINICALTRIALS.GOV

NCT04255381 (https://clinicaltrials.gov/ct2/show/NCT04255381).

Efficacy of a Hybrid Closed-Loop Solution in Patients With Excessive Time in Hypoglycaemia: A Post Hoc Analysis of Trials With DBLG1 System

BACKGROUND

Automated insulin delivery is an efficient treatment for patients with type 1 diabetes. Little is known on its impact on patients with excessive time in hypoglycaemia.

METHODS

We performed a post hoc analysis of three randomized control trials that used the DBLG1 (Diabeloop Generation 1) hybrid closed-loop solution. Patients whose time below 70 mg/dL during baseline, open-loop phase exceeded 5% were selected. The outcomes were the differences between the closed-loop and the open-loop phases in time in various ranges and Glycemia Risk Index (GRI).

RESULTS

We identified 45 patients exhibiting ≥5% of time below 70 mg/dL during the open-loop phase. Under closed-loop, the time in hypoglycaemia (54 to <70 mg/dL) dropped from 7.9% (SD 2.4) to 3.2% (SD 1.6) (difference -4.7% [-5.3; -4.1], P < 10-4). The time below 54 mg/dL decreased from 1.9% (SD 1.3) to 0.8% (SD 0.7) (difference -0.9% [-1.4; -0.8], P < 10-4). The time in range (TIR 70-180 mg/dL) improved from 63.3 (SD 9.5) to 68.2% (SD 8.2) (difference 5.1% [2.9; 7.0], P < 10-4). The GRI improved from 51.2 (SD 12.4) to 38.0 (SD 10.9) (difference 13.2 [10.4; 16.0], P < 10-4).

CONCLUSION

DBLG1 decreased time in hypoglycaemia by more than 50% even in patients with excessive time in hypoglycaemia at baseline, while also improving both TIR and GRI, under real-life conditions. The improvement in GRI (13.2%) exceeded that of the improvement in TIR (5.1%) indicating that in this data set, GRI was more sensitive than TIR to the improvement in glycaemia achieved with closed-loop. These results support the safety and efficacy of this treatment.

Weight Gain and Glycemic Control in Adults with Type 1 Diabetes in the T1D Exchange Registry

Aim: The impact of weight gain on insulin dosage and glycemic control in adults with type 1 diabetes (T1D) aged 25 years and older was investigated in the T1D Exchange Registry participants. Methods: Participants were categorized into four groups based on their change in weight from T1D Exchange registry enrollment to year 5: stable weight (-5 to <5 lb), gained 5 to <10 lb, gained 10 to <20 lb, or gained ≥20 lb. Those who lost >5 lb were excluded. The primary outcomes were glucose control, as measured by glycosylated hemoglobin (HbA1c), and total daily insulin dose (TDD) at year 5. Linear regression models were used to evaluate the association between weight gain, HbA1c, and TDD. Results: There were 1969 participants included in the analyses. The mean ± standard deviation age was 45 ± 13 years, 57% were female, and 92% were White non-Hispanic. For those with an enrollment HbA1c <8.0%, the mean HbA1c at year 5 was higher for those who gained ≥20 lb compared to those with a stable weight of -5 to <5 lb (7.4% ± 1.1% vs. 7.2% ± 0.8%, respectively; P = 0.005). For this cohort, the mean TDD at year 5 increased from 49 ± 25 to 61 ± 29 U for those who gained ≥20 lb, while decreased from 45 ± 27 to 44 ± 25 U for those with stable weight of -5 to <5 lb (P < 0.001). Among participants with an enrollment HbA1c ≥9.0%, the mean HbA1c at year 5 was statistically insignificant at 8.4% ± 1.3% for those who gained ≥20 lb compared to 9.2% ± 1.7% for those with a stable weight of -5 to <5 lb (P = 0.09). Conclusion: Significant weight gain in adults with T1D who had good to adequate glycemic control was associated with modest deterioration in glucose control despite an increase in TDD. Worsening glucose control may indicate insulin resistance related to weight gain despite significantly increased insulin dosage which was insufficient to maintain adequate glycemic control.

Increased Plasma Branched Short-Chain Fatty Acids and Improved Glucose Homeostasis: The Microbiome and Insulin Longitudinal Evaluation Study (MILES)

Short-chain fatty acids (SCFAs) have been extensively studied for potential beneficial roles in glucose homeostasis and risk of diabetes; however, most of this research has focused on butyrate, acetate, and propionate. The effect on metabolism of branched SCFAs (BSCFAs; isobutyrate, isovalerate, and methylbutyrate) is largely unknown. In a cohort of 219 non-Hispanic White participants and 126 African American participants, we examined the association of BSCFA with dysglycemia (prediabetes and diabetes) and oral glucose tolerance test-based measures of glucose and insulin homeostasis, as well as with demographic, anthropometric, lifestyle, and lipid traits, and other SCFAs. We observed a bimodal distribution of BSCFAs, with 25 individuals having high levels (H-BSCFA group) and 320 individuals having lower levels (L-BSCFA group). The prevalence of dysglycemia was lower in the H-BSCFA group compared with the L-BSCFA group (16% vs. 49%; P = 0.0014). This association remained significant after adjustment for age, sex, race, BMI, and levels of other SCFAs. Consistent with the lower rate of dysglycemia, fasting and postprandial glucose levels were lower and the disposition index was higher in the H-BSCFA group. Additional findings in H-BSCFA versus L-BSCFA included lower fasting and postprandial C-peptide levels and lower insulin clearance without differences in insulin levels, insulin sensitivity, insulin secretion, or other variables examined, including diet and physical activity. As one of the first human studies associating higher BSCFA levels with lower odds of dysglycemia and improved glucose homeostasis, this study sets the stage for further investigation of BSCFA as a novel target for prevention or treatment of diabetes.

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