Induction of remission in diabetes by lowering blood glucose

Genetic Risk Phenotypes for Type 2 Diabetes Differ with Ancestry in US Adults with Diabetes and Overweight/Obesity

BACKGROUND

Type 2 diabetes (T2D) risk is higher among non-Hispanic black (NHB) and Hispanic individuals, for reasons that are unclear.

AIMS

With this cross-sectional study, we tested the hypothesis that racial disparities in T2D prevalence can be partially traced to heterogeneity in etiology, as indicated by genetic subtypes that reflect distinct T2D phenotypes.

METHODS

Using a diverse sample of 361 US adults with T2D (69.5% women; 34.1% NHB; 13.9% Hispanic), we derived genetic risk scores (GRS) representing five distinct T2D pathophysiological pathways from 94 loci: β-cell, proinsulin, obesity, lipodystrophy, and liver/lipid. Genetic predisposition for insulin resistance (IR) was also assessed using a 52-SNP IR risk score.

RESULTS

The β-cell and proinsulin scores (as median [IQR]) were higher among NHB participants relative to NHW and Hispanics (β-cell GRS [NHB, 0.842(0.784-0.887) vs. NHW, 0.762(0.702-0.835) and Hispanic, 0.772(0.717-0.848)]); proinsulin GRS (NHB, 1.006[0.973-1.070] vs. NHW, 0.969[0.853-1.044] and Hispanic, 0.976[0.901-1.048]), whereas the liver/lipid and 52-SNP IR scores were higher in both NHB and Hispanic participants versus NHW (liver/lipid GRS [NHB, 1.09(0.78-1.18) and Hispanic, 0.895(0.736-1.227) vs. NHW, 0.794(0.666-1.157)]); 52-SNP IR GRS (NHB, 0.0095[0.009-0.010] and Hispanic, 0.0096 [0.0092-0.0101] vs. NHW, 0.0090[0.0084-0.0095]).

CONCLUSIONS

Impaired β-cell function may underlie T2D etiology more profoundly in NHB, whereas hepatic dysfunction, lipid metabolism abnormalities, and genetic IR contribute to T2D etiology to a greater degree in both NHB and Hispanics. Further validation of these findings may form the basis for a personalized medicine approach to prevention and treatment of T2D.

Metabolic interventions as adjunctive therapies to insulin in type 1 diabetes: Current clinical landscape and perspectives

Type 1 diabetes (T1D) is classically characterized as an autoimmune disease wherein the immune system erroneously attacks insulin-producing pancreatic β-cells, causing insulin insufficiency and severe metabolic dysregulation. However, intensive investigation and numerous clinical trials with immunotherapies have been largely unable to significantly alter the course of disease. Currently, there is no effective way to prevent or cure T1D, and insulin remains the cornerstone of T1D treatment. In recent years, a growing body of research suggests that β-cells actively contribute to the immune response and to disease development. Factors including glucotoxicity, lipotoxicity, inflammation, endoplasmic reticulum (ER) and oxidative stress can induce β-cell apoptosis and senescence, further promoting insulitis. Recent studies highlight the importance of targeting metabolic control for T1D management and treatment. Metabolic interventions, through their direct and indirect impacts on β-cells, have shown promise in preserving β-cell function. These interventions can reduce glucose toxicity, alleviate oxidative stress and inflammation, enhance insulin sensitivity, and indirectly mitigate the autoimmune responses. By preserving β-cell function, individuals with T1D attain better glycaemic control, reduced complication risks and exhibit improved overall metabolic health. Here, we provide an overview of insights from clinical studies, systematic reviews and meta-analyses that collectively demonstrate that adjunctive metabolic interventions can enhance glycaemic control, reduce insulin requirements and mitigate adverse effects associated with insulin monotherapy. They also show potential for halting disease progression, preserving residual β-cell function and improving long-term outcomes for newly diagnosed individuals. Future research should focus on optimizing these treatment strategies and establishing their long-term efficacy and safety.

A Glycemic Threshold Above Which the Improvement of β-Cell Function and Glycemia in Response to Insulin Therapy Is Amplified in Early Type 2 Diabetes: The Reversal of Glucotoxicity

OBJECTIVE

Alleviation of unrecognized glucotoxicity, with resultant recovery of β-cell function, could amplify the glucose-lowering effect of pharmacotherapy and contribute to the variable therapeutic response observed among patients with type 2 diabetes (T2D). However, clinical evidence supporting this concept is lacking. Short-term intensive insulin therapy (IIT) can ameliorate glucotoxicity and improve β-cell function in early T2D. Thus, for evidence of recovery of glucotoxicity-associated β-cell dysfunction, we sought to determine whether there exists a baseline fasting glucose threshold above which the post-IIT improvement in both β-cell function and glycemia is amplified.

RESEARCH DESIGN AND METHODS

IIT (glargine, lispro) was administered for 3 weeks to 108 adults with T2D (mean duration 1.8 ± 1.4 years). Oral glucose tolerance tests before and after IIT enabled assessment of β-cell function by Insulin Secretion-Sensitivity Index-2 and insulinogenic index/HOMA-insulin resistance. For each level of baseline fasting glycemia from 6.0 to 10.5 mmol/L, we modeled the difference in IIT-induced percentage change in β-cell function between those at/above the indicated glucose level and those below it.

RESULTS

The relationship between baseline fasting glucose and the differential change in β-cell function was nonlinear. Instead, this relationship was best fit by a cubic regression model with inflection (amplification) at fasting glucose at 9.3 mmol/L. Moreover, baseline fasting glucose at 9.3 mmol/L also identified the inflection point at which nonlinear reductions in fasting glucose and 2-h glucose, respectively, were both amplified.

CONCLUSIONS

The respective improvements in β-cell function and glycemia in response to short-term IIT are amplified in those in whom baseline fasting glucose exceeds a defined threshold, consistent with reversal of glucotoxicity.

Contemporary Clinical Perspectives on Targeting Remission of Type 2 Diabetes

It has long been known that some patients with type 2 diabetes (T2DM) can experience sustained metabolic improvement to near-normal levels of glycemia either spontaneously or after medical intervention. Now recognized as remission of diabetes, this intriguing state is currently more feasible than ever before due to profound advances in metabolic surgery, pharmacologic therapy, and regimens of lifestyle modification. This enhanced capacity to induce remission has revealed new pathophysiologic insights, including the presence of a reversible component of the pancreatic beta-cell dysfunction that otherwise drives the chronic progressive nature of T2DM. In doing so, it has changed the therapeutic landscape by offering new potential management objectives and considerations for patients and providers. However, the excitement around these developments must also be tempered by the sobering realities of our current understanding of remission, including the recognition that this condition may not be permanent (resulting in glycemic relapse over time) and that beta-cell function may not be normalized in the setting of remission. These limitations highlight both the many gaps in our current understanding of remission and the caution with which clinical discussions must be handled for clear patient-directed communication of the pros and cons of targeting this outcome in practice. In this mini-review, we consider this rapidly growing literature, including its implications and its limitations, and thereby seek to provide objective balanced perspectives on targeting remission of T2DM in current clinical care.