Incidence and correlated factors of beta cell failure in a 4-year follow-up of patients with type 2 diabetes: a longitudinal analysis of the BETADECLINE study

Temporal trends in the starting of insulin therapy in type 2 diabetes in Italy: data from the AMD Annals initiative

AIMS

Opportunities and needs for starting insulin therapy in Type 2 diabetes (T2D) have changed overtime. We evaluated clinical characteristics of T2D subjects undergoing the first insulin prescription during a 15-year-observation period in the large cohort of the AMD Annals Initiative in Italy.

METHODS

Data on clinical and laboratory variables, complications and concomitant therapies and the effects on glucose control after 12 months were evaluated in T2D patients starting basal insulin as add-on to oral/non-insulin injectable agents, and in those starting fast-acting in add-on to basal insulin therapy in three 5-year periods (2005-2019).

RESULTS

We evaluated data from 171.688 T2D subjects who intensified therapy with basal insulin and 137.225 T2D patients who started fast-acting insulin. Overall, intensification with insulin occurred progressively earlier over time in subjects with shorter disease duration. Moreover, the percentage of subjects with HbA1c levels > 8% at the time of basal insulin initiation progressively decreased. The same trend was observed for fast-acting formulations. Clinical characteristics of subjects starting insulin did not change in the three study-periods, although all major risk factors improved overtime. After 12 months from the starting of basal or fast-acting insulin therapy, mean HbA1c levels decreased in all the three investigated time-periods, although mean HbA1c levels remained above the recommended target.

CONCLUSIONS

In this large cohort of T2D subjects, a progressively earlier start of insulin treatment was observed during a long observation period, suggesting a more proactive prescriptive approach. However, after 12 months from insulin prescription, in many patients, HbA1c levels were still out-of-target.

Changing the approach to type 2 diabetes treatment: A comparison of glucagon-like peptide-1 receptor agonists and sulphonylureas across the continuum of care

Despite the importance of individualised strategies for patients with type 2 diabetes mellitus (T2DM) and the availability of alternative treatments, including glucagon-like peptide-1 receptor agonists (GLP-1 RAs), sulphonylureas are still widely used in practice. Clinical evidence shows that GLP-1 RAs may provide better and more durable glycaemic control than sulphonylureas, with lower risk of hypoglycaemia. Other reported benefits of GLP-1 RAs include weight loss rather than weight gain (as observed with sulphonylureas), blood pressure reduction and improvement in lipid profiles. In general, the main adverse events with GLP-1 RAs are gastrointestinal in nature. The respective modes of action of GLP-1 RAs and sulphonylureas contribute to differences in the durability of glycaemic control (related to effects on beta-cells) and effects on body weight. Moreover, the glucose-dependent mode of action of GLP-1 RAs, which favours a low incidence of hypoglycaemia, contrasts with the glucose-independent mode of action of sulphonylureas. Evidence from cardiovascular outcomes trials indicates a consistent finding of cardiovascular safety across the GLP-1 RAs and suggests a class benefit for the long-acting GLP-1 RAs in reducing three-point major adverse cardiovascular events, cardiovascular mortality and all-cause mortality. In contrast, potential concerns relating to an increased incidence of adverse cardiovascular events with sulphonylureas have yet to be fully resolved. Recent updates to management guidelines recommend that treatment selection for patients with T2DM should consider clinical trial evidence of cardiovascular safety. Available evidence suggests that this selection should give preference to GLP-1 RAs over sulphonylureas, especially for patients at high cardiovascular risk.

Over time evaluation of glycaemic control in direct-acting antiviral-treated hepatitis C virus/diabetic individuals with chronic hepatitis or with cirrhosis

BACKGROUND

Data concerning the impact of hepatitis C virus (HCV) cure on type 2 diabetes mellitus (T2DM) are controversial. The aim of the study was to evaluate the effects of anti-HCV direct-acting antiviral (DAA) treatments on long-term glucose control in HCV/T2DM patients with chronic hepatitis C (CHC) or with cirrhosis.

METHODS

One hundred and eighty-two consecutive HCV/T2DM patients who achieved a viral clearance by DAA treatment were enrolled. Seventy or 182 of them had CHC, and 112 had cirrhosis. Clinical, biochemical and instrumental parameters were recorded at baseline and at 48, 96 and 120 weeks (48w, 96w and 120w, respectively) after stopping DAA therapy.

RESULTS

At baseline, the overall study population had a mean of glycated haemoglobin (HbA1c) value of 7.2% (ranging from 5 to 11.2), without any significant differences between CHC and cirrhosis [7.1 and 7.2, respectively]. Evaluation over time of HbA1c variations showed a significant improvement of glucose control at all post-treatment time points compared with baseline in CHC patients (P = .001). In cirrhotic patients, a significant decrease of HbA1c levels was only found when comparing HbA1c values between baseline and 48w time-point (P = .001), whereas this improvement disappeared at both 98w and 120w (P = .8 and P = .3, respectively). Multivariate logistic regression analysis showed that patients with chronic hepatitis have a 2.5 (CI 1.066-5.945) times greater chance of achieving an improvement of glycaemic values than patients with liver cirrhosis (P = .035).

CONCLUSION

DAA-based HCV cure induces a significant and persistent amelioration of glycaemic control in HCV/diabetic patients with chronic hepatitis, whereas cirrhotic HCV/diabetic subjects have only a transient benefit from the virus elimination.

The impact of phenotype, ethnicity and genotype on progression of type 2 diabetes mellitus

AIM

To conduct a comprehensive review of studies of glycaemic deterioration in type 2 diabetes and identify the major factors influencing progression.

METHODS

We conducted a systematic literature search with terms linked to type 2 diabetes progression. All the included studies were summarized based upon the factors associated with diabetes progression and how the diabetes progression was defined.

RESULTS

Our search yielded 2785 articles; based on title, abstract and full-text review, we included 61 studies in the review. We identified seven criteria for diabetes progression: 'Initiation of insulin', 'Initiation of oral antidiabetic drug', 'treatment intensification', 'antidiabetic therapy failure', 'glycaemic deterioration', 'decline in beta-cell function' and 'change in insulin dose'. The determinants of diabetes progression were grouped into phenotypic, ethnicity and genotypic factors. Younger age, poorer glycaemia and higher body mass index at diabetes diagnosis were the main phenotypic factors associated with rapid progression. The effect of genotypic factors on progression was assessed using polygenic risk scores (PRS); a PRS constructed from the genetic variants linked to insulin resistance was associated with rapid glycaemic deterioration. The evidence of impact of ethnicity on progression was inconclusive due to the small number of multi-ethnic studies.

CONCLUSION

We have identified the major determinants of diabetes progression-younger age, higher BMI, higher HbA1c and genetic insulin resistance. The impact of ethnicity is uncertain; there is a clear need for more large-scale studies of diabetes progression in different ethnic groups.

Stem-cell based organ-on-a-chip models for diabetes research

Diabetes mellitus (DM) ranks among the severest global health concerns of the 21st century. It encompasses a group of chronic disorders characterized by a dysregulated glucose metabolism, which arises as a consequence of progressive autoimmune destruction of pancreatic beta-cells (type 1 DM), or as a result of beta-cell dysfunction combined with systemic insulin resistance (type 2 DM). Human cohort studies have provided evidence of genetic and environmental contributions to DM; yet, these studies are mostly restricted to investigating statistical correlations between DM and certain risk factors. Mechanistic studies, on the other hand, aimed at re-creating the clinical picture of human DM in animal models. A translation to human biology is, however, often inadequate owing to significant differences between animal and human physiology, including the species-specific glucose regulation. Thus, there is an urgent need for the development of advanced human in vitro models with the potential to identify novel treatment options for DM. This review provides an overview of the technological advances in research on DM-relevant stem cells and their integration into microphysiological environments as provided by the organ-on-a-chip technology.

Beta cell stress in a 4-year follow-up of patients with type 2 diabetes: A longitudinal analysis of the BetaDecline Study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with a progressive deterioration in beta cell function and loss of glycaemic control. Clinical predictors of beta cell failure are needed to guide appropriate therapy.

METHODS

A prospective evaluation of a large set of potential predictors of beta cell stress, measured as change in the proinsulin/insulin (PI/I) ratio, was conducted in a cohort of 235 outpatients with T2DM on stable treatment with oral hypoglycaemic agents or diet followed up for ~4 years (median value 3.9 years; interquartile range 3.8-4.1 years).

RESULTS

Overall, metabolic control deteriorated over time, with a significant increase in glycated haemoglobin (HbA1c; P < .0001), proinsulin (P < .0001), and PI/I ratio (P = .001), without significant changes in the homeostatic model assessment of insulin resistance. Multivariate regression analysis showed that for each 1% (10.9 mmol/mol) increase from baseline in HbA1c, the risk of beta cell stress increased by 3.8 times; for each 1% (10.9 mmol/mol) incremental increase in HbA1c during the study, risk of beta cell stress increased by 2.25 times that at baseline. By contrast, baseline anthropometric and clinical variables, lipid profile, inflammatory markers (PCR, IL-6), non-esterified fatty acids, and current therapies did not independently influence PI/I ratio variation during follow-up.

CONCLUSIONS

In this cohort of patients with T2DM, beta cell function progressively deteriorated despite current therapies. Among a large set of clinical and biochemical predictors, only baseline HbA1c levels and their deterioration overtime were associated with higher beta cell stress over time.

Beta-cell Insufficiency

‘Beta-cell failure’ is a frequently used term to describe the structural and functional inability of the cells to fulfil their metabolic responsibility. This editorial reviews the anatomy and physiology of the beta cell, and describes factors which regulate this. The authors focus on semantics, comparing the phrases ‘beta-cell failure’, ‘functional mass’, and ‘beta-cell insufficiency’. They suggest the use of ‘beta-cell insufficiency’, with descriptors such as ‘partial’ and ‘complete’, or ‘reversible’ and ‘irreversible’, to convey betacell dysfunction in type 2 diabetes. A three-phase taxonomic structure: beta-cell sufficiency, partial/reversible beta-cell insufficiency and complete/irreversible beta-cell insufficiency, is proposed as a tool to understand pathophysiology and facilitate therapeutic decision-making.

Functional Characterization of Native, High-Affinity GABAA Receptors in Human Pancreatic β Cells

In human pancreatic islets, the neurotransmitter γ-aminobutyric acid (GABA) is an extracellular signaling molecule synthesized by and released from the insulin-secreting β cells. The effective, physiological GABA concentration range within human islets is unknown. Here we use native GABA_A receptors in human islet β cells as biological sensors and reveal that 100–1000 nM GABA elicit the maximal opening frequency of the single-channels. In saturating GABA, the channels desensitized and stopped working. GABA modulated insulin exocytosis and glucose-stimulated insulin secretion. GABA_A receptor currents were enhanced by the benzodiazepine diazepam, the anesthetic propofol and the incretin glucagon-like peptide-1 (GLP-1) but not affected by the hypnotic zolpidem. In type 2 diabetes (T2D) islets, single-channel analysis revealed higher GABA affinity of the receptors. The findings reveal unique GABA_A receptors signaling in human islets β cells that is GABA concentration-dependent, differentially regulated by drugs, modulates insulin secretion and is altered in T2D.

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In human islets GABA (≤μM) activates β cell-specific GABA_A receptors that become supersensitive to GABA in type 2 diabetes.

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GABA_A receptors activity in β cells is enhanced by diazepam, anesthetics, the incretin GLP-1 but not the hypnotic zolpidem.

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GABA modulates rate of insulin granule exocytosis and glucose-stimulated insulin secretion.

GABA is a signal molecule in the brain but is also secreted by the insulin-producing β cells in pancreatic islets. GABA has many roles in human islets that most aim at optimizing function and survival of β cells. In the report by Korol, Jin et al. the authors identify and characterize the molecular unit that GABA binds to in human β cells, the GABA_A receptors. These receptors normally sensitive become super-sensitive to GABA in type 2 diabetes. The GABA_A receptors regulate insulin secretion and can themselves be regulated by the anxiolytic diazepam, anesthetics, the incretin GLP-1 but not the hypnotic zolpidem. Targeting GABA signaling in human islets in diabetes mellitus is likely to be a part of the solution when curing diabetes.

Five-Year Predictors of Insulin Initiation in People with Type 2 Diabetes under Real-Life Conditions

We performed a real-life analysis of clinical and laboratory parameters, in orally treated T2DM patients aiming at identifying predictors of insulin treatment initiation. Overall, 366955 patients (55.8% males, age 65 ± 11 years, diabetes duration 7 ± 8 years) were followed up between 2004 and 2011. Each patient was analyzed step-by-step until either eventually starting insulin treatment or getting to the end of the follow-up period. Patients switching to insulin showed a worse global risk profile, longer disease duration (10 ± 9 years vs. 6 ± 7 years, respectively; p < 0.001), higher HbA1c (8.0 ± 1.6% vs. 7.2 ± 1.5%, respectively; p < 0.001), higher triglycerides, a greater prevalence of arterial hypertension, antihypertensive, lipid-lowering and aspirin treatment, a higher rate of nonproliferative/proliferative retinopathy, and a nearly 4 times lower prevalence of the "diet alone." They also showed a higher prevalence of subjects with eGFR < 60 ml/min/1.73 m² (24.0% vs. 16.2%, respectively; p < 0.001). Multivariate analysis identified diabetes duration, HbA1c, triglyceride and low HDL-C values, presence of retinopathy or renal dysfunction, and sulphonylurea utilization (the risk being approximately 3 times greater in the latter case) as independent predictors of insulin treatment initiation. LDL-C, lipid-lowering treatment, and overweight/obese seem to be protective. Results of tree analysis showed that patients on sulphonylurea, with high HbA1c, eGFR below 50 ml/min/1.73 m², and at least 5-year disease duration, are at very high risk to start insulin treatment. We have to stick to this real-life picture, of course, until enough data are collected on patients treated with innovative medications which are expected to improve beta cell survival and further delay treatment-related insulin requirement.

Impact of insulin sensitivity, beta-cell function and glycaemic control on initiation of second-line glucose-lowering treatment in newly diagnosed type 2 diabetes

AIMS

The aim of this study was to investigate whether insulin sensitivity, beta-cell function or glycaemic control at diagnosis predict initiation of second-line treatment in newly diagnosed type 2 diabetes.

RESEARCH DESIGN AND METHODS

Type 2 diabetes patients (n = 138) undergoing initial metformin monotherapy (age [mean ± SD], 52 ± 10 years; 67% males; BMI, 32 ± 6 kg/m² ) from the prospective German Diabetes Study cohort (n = 398) were included. Patients remained under care of their general practitioners, yet underwent detailed metabolic characterization after diabetes diagnosis for study purposes (hyperinsulinemic-euglycemic clamp, M value; i.v. glucose tolerance test, incremental C-peptide area under the curve_{0-60 minutes,} CP iAUC). The associations of baseline M value, CP iAUC, fasting glucose and HbA1c with time to second-line therapy were assessed using parametric survival analysis, accounting for interval-censoring.

RESULTS

Second-line treatment was initiated in 26% of newly diagnosed type 2 diabetes patients within the first 3.3 years after diagnosis, using mostly DPP-4 inhibitors or GLP-1 receptor agonists (64%). In age-, sex- and BMI-adjusted survival models, higher baseline HbA1c and fasting glucose values were associated with earlier treatment intensification. Lower baseline M value and C-peptide secretion (CP iAUC) were also related to an earlier initiation of second-line treatment. In the best multivariable model, baseline HbA1c ≥ 7% (hazard ratio, HR; 95% CI: 3.18; 1.35-7.50) and fasting glucose ≥140 mg/dL (HR, 2.45; 95% CI, 1.04-5.78) were associated with shorter time to second-line therapy, adjusting for age, sex and BMI.

CONCLUSIONS

Baseline hyperglycaemia is a strong predictor of requirement of early intensification of glucose-lowering therapy in newly diagnosed type 2 diabetes.

Effects on α- and β-cell function of sequentially adding empagliflozin and linagliptin to therapy in people with type 2 diabetes previously receiving metformin: An exploratory mechanistic study

AIMS

To investigate the effect of sequential treatment escalation with empagliflozin and linagliptin on laboratory markers of α- and β-cell function in people with type 2 diabetes mellitus (T2DM) insufficiently controlled on metformin monotherapy.

RESEARCH DESIGN AND METHODS

A total of 44 people with T2DM received 25 mg empagliflozin for a duration of 1 month in an open-label fashion (treatment period 1 [TP1]). Thereafter, they were randomized to a double-blind add-on therapy with linagliptin 5 mg or placebo (treatment period 2 [TP2]) for 1 additional month. α- and β-cell function was assessed using a standardized liquid meal test and an intravenous (i.v.) glucose challenge. Efficacy measures comprised the areas under the curve for glucose, insulin, proinsulin and glucagon after the liquid meal test and the assessment of fast and late-phase insulin release after an i.v. glucose load with a subsequent hyperglycaemic clamp.

RESULTS

Empagliflozin reduced fasting and postprandial plasma glucose levels, associated with a significant reduction in postprandial insulin levels and an improvement in the conversion rate of proinsulin (TP1). The addition of linagliptin during TP2 further improved postprandial glucose levels, probably as a result of a marked reduction in postprandial glucagon concentrations (TP2). The insulin response to an i.v. glucose load increased during treatment with empagliflozin (TP1), and further improved after the addition of linagliptin (TP2).

CONCLUSION

After metformin failure, sequential treatment escalation with empagliflozin and linagliptin is an attractive treatment option because of the additive effects on postprandial glucose control, probably mediated by complementary effects on α- and β-cell function.