Glucocrinology of Modern Sulfonylureas: Clinical Evidence and Practice-Based Opinion from an International Expert Group

Sulfonylureas exert antidiabetic action on adipocytes by inhibition of PPARγ serine 273 phosphorylation

OBJECTIVE

Sulfonylureas (SUs) are still among the mostly prescribed antidiabetic drugs with an established mode of action: release of insulin from pancreatic β-cells. In addition, effects of SUs on adipocytes by activation of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) have been described, which might explain their insulin-sensitizing potential observed in patients. However, there is a discrepancy between the impact of SUs on antidiabetic action and their rather moderate in vitro effect on PPARγ transcriptional activity. Recent studies have shown that some PPARγ ligands can improve insulin sensitivity by blocking PPARγ Ser-273 phosphorylation without having full agonist activity. It is unknown if SUs elicit their antidiabetic effects on adipocytes by inhibition of PPARγ phosphorylation. Here, we investigated if binding of SUs to PPARγ can interfere with PPARγ Ser-273 phosphorylation and determined their antidiabetic actions in vitro in primary human white adipocytes and in vivo in high-fat diet (HFD) obese mice.

METHODS

Primary human white preadipocytes were differentiated in the presence of glibenclamide, glimepiride and PPARγ ligands rosiglitazone and SR1664 to compare PPARγ Ser-273 phosphorylation, glucose uptake and adipokine expression. Transcriptional activity at PPARγ was determined by luciferase assays, quantification of PPARγ Ser-273 phosphorylation was determined by Western blotting and CDK5 kinase assays. In silico modelling was performed to gain insight into the binding characteristics of SUs to PPARγ. HFD mice were administered SUs and rosiglitazone for 6 days. PPARγ Ser-273 phosphorylation in white adipose tissue (WAT), body composition, glucose tolerance, adipocyte morphology and expression levels of genes involved in PPARγ activity in WAT and brown adipose tissue (BAT) were evaluated.

RESULTS

SUs inhibit phosphorylation of PPARγ at Ser-273 in primary human white adipocytes and exhibit a positive antidiabetic expression profile, which is characterized by up regulation of insulin-sensitizing and down regulation of insulin resistance-inducing adipokines. We demonstrate that SUs directly bind to PPARγ by in silico modelling and inhibit phosphorylation in kinase assays to a similar extend as rosiglitazone and SR1664. In HFD mice SUs reduce PPARγ phosphorylation in WAT and have comparable effects on gene expression to rosiglitazone. In BAT SUs increase UCP1 expression and reduce lipid droplets sizes.

CONCLUSIONS

Our findings indicate that a part of SUs extra-pancreatic effects on adipocytes in vitro and in vivo is probably mediated via their interference with PPARγ phosphorylation rather than via classical agonistic activity at clinical concentrations.

Associations among diabetes medication use, serum magnesium, and insulin resistance in a cohort of older Puerto Rican adults

BACKGROUND

Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear.

OBJECTIVES

We aimed to examine the association between diabetes medication and hypomagnesemia and evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort.

METHODS

Adults from the Boston Puerto Rican Health Study were included (n = 1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg <0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-y HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) of ≥6.5%.

RESULTS

Mean age at baseline was 59.0 ± 7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: β (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [β (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: β (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones.

CONCLUSIONS

Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

[Preoperative evaluation of adult patients before elective, non-cardiothoracic surgery : A joint recommendation of the German Society for Anesthesiology and Intensive Care Medicine, the German Society for Surgery and the German Society for Internal Medicine]

The 70 recommendations summarize the current status of preoperative risk evaluation of adult patients prior to elective non-cardiothoracic surgery. Based on the joint publications of the German scientific societies for anesthesiology and intensive care medicine (DGAI), surgery (DGCH), and internal medicine (DGIM), which were first published in 2010 and updated in 2017, as well as the European guideline on preoperative cardiac risk evaluation published in 2022, a comprehensive re-evaluation of the recommendation takes place, taking into account new findings, the current literature, and current guidelines of international professional societies. The revised multidisciplinary recommendation is intended to facilitate a structured and common approach to the preoperative evaluation of patients. The aim is to ensure individualized preparation for the patient prior to surgery and thus to increase patient safety. Taking into account intervention- and patient-specific factors, which are indispensable in the preoperative risk evaluation, the perioperative risk for the patient should be minimized and safety increased. The recommendations for action are summarized under "General Principles (A)," "Advanced Diagnostics (B)," and the "Preoperative Management of Continuous Medication (C)." For the first time, a rating of the individual measures with regard to their clinical relevance has been given in the present recommendation. A joint and transparent agreement is intended to ensure a high level of patient orientation while avoiding unnecessary preliminary examinations, to shorten preoperative examination procedures, and ultimately to save costs. The joint recommendation of DGAI, DGCH and DGIM reflects the current state of knowledge as well as the opinion of experts. The recommendation does not replace the individualized decision between patient and physician about the best preoperative strategy and treatment.

Effects of Initial Combinations of Gemigliptin Plus Metformin Compared with Glimepiride Plus Metformin on Gut Microbiota and Glucose Regulation in Obese Patients with Type 2 Diabetes: The INTESTINE Study

The efficacy and safety of medications can be affected by alterations in gut microbiota in human beings. Among antidiabetic medications, incretin-based therapy such as dipeptidyl peptidase 4 inhibitors might affect gut microbiomes, which are related to glucose metabolism. This was a randomized, controlled, active-competitor study that aimed to compare the effects of combinations of gemigliptin−metformin vs. glimepiride−metformin as initial therapies on gut microbiota and glucose homeostasis in drug-naïve patients with type 2 diabetes. Seventy drug-naïve patients with type 2 diabetes (mean age, 52.2 years) with a glycated hemoglobin (HbA1c) level ≥7.5% were assigned to either gemigliptin−metformin or glimepiride−metformin combination therapies for 24 weeks. Changes in gut microbiota, biomarkers linked to glucose regulation, body composition, and amino acid blood levels were investigated. Although both treatments decreased the HbA1c levels significantly, the gemigliptin−metformin group achieved HbA1c ≤ 7.0% without hypoglycemia or weight gain more effectively than did the glimepiride−metformin group (59% vs. 24%; p < 0.05). At the phylum level, the Firmicutes/Bacteroidetes ratio tended to decrease after gemigliptin−metformin therapy (p = 0.065), with a notable depletion of taxa belonging to Firmicutes, including Lactobacillus, Ruminococcus torques, and Streptococcus (all p < 0.05). However, regardless of the treatment modality, a distinct difference in the overall gut microbiome composition was noted between patients who reached the HbA1c target goal and those who did not (p < 0.001). Treatment with gemigliptin−metformin resulted in a higher achievement of the glycemic target without hypoglycemia or weight gain, better than with glimepiride−metformin; these improvements might be related to beneficial changes in gut microbiota.

Glucodynamics and glucocracy in type 2 diabetes mellitus: clinical evidence and practice-based opinion on modern sulfonylurea use, from an International Expert Group (South Asia, Middle East & Africa) via modified Delphi method

Type 2 diabetes mellitus (T2DM) is a global epidemic. According to international guidelines, the management protocol of T2DM includes lowering of blood glucose, along with preventing disease-related complications and maintaining optimal quality of life. Further, the guidelines recommend the use of a patient-centric approaches for the management of T2DM; however, Asian population is underrepresented in landmark cardiovascular outcome trials (CVOTs). There are several guidelines available today for the diagnosis and management of T2DM, and hence there is much confusion among practitioners about which guidelines to follow. A group of thirty international clinical experts comprising of endocrinologists, diabetologists and cardiologist from South Asia, Middle East and Africa met at New Delhi, India on February 8 and 9, 2020 and developed an international expert opinion statements via a structured modified Delphi method on the glucodynamic properties of OADs and the glucocratic treatment approach for the management of T2DM. In this modified Delphi consensus report, we document the glucodynamic properties of Modern SUs in terms of glucoconfidence, glucosafety, and gluconomics. According to glucodynamics theory, an ideal antidiabetic drug should be efficacious, safe, and affordable. Modern SUs as a class of OADs that have demonstrated optimal glucodynamics in terms of glucoconfidence, glucosafety, and gluconomics. Hence, modern SUs are most suitable second line drug after metformin for developing countries. Based on the current evidence, we recommend a glucocratic approach for the treatment of T2DM, where an individualized treatment plan with phenotype, lifestyle, environmental, social, and cultural factors should be considered for persons with T2DM in the South Asian, Middle Eastern and African regions.

Glimepiride and Metformin Combinations in Diabetes Comorbidities and Complications: Real-World Evidence

Objective To evaluate the usage of various strengths of glimepiride and metformin fixed-dose combinations in the management of type 2 diabetes mellitus (T2DM) patients with comorbidities and complications. Methods A retrospective, non-randomized, non-comparative, multi-centric real-world study included T2DM patients (age > 18 years) taking glimepiride and metformin fixed-dose combinations. Age, duration of diabetes, diabetes complications, comorbidities (hypertension and dyslipidemia), dosage frequency, and concomitant medications were analyzed from medical charts. Results A total of 4858 T2DM patients were included, with a mean age of 52.67 years and males being predominant in the study population (60.85%). The laboratory investigations showed a mean glycated hemoglobin (HbA1c) of 7.5, low-density lipoprotein (LDL) cholesterol of 104.81 ± 38.19 mg/dL, and serum creatinine of 0.88 ± 0.26 mg/dL. Around 2055 (42.30%) T2DM patients were hypertensive, and telmisartan alone and a telmisartan-based combination were the drugs of choice for hypertension management. Similarly, 1073 (22.08%) T2DM patients were having dyslipidemia and were primarily managed with rosuvastatin and its combination in 664 (62%) patients. Macrovascular complications were observed in 339 (6.97%) T2DM patients, among which coronary artery disease (CAD) had maximum prevalence, affecting 273 (5.61%) T2DM patients. Microvascular complications were 1010 (20.79%) T2DM patients, among which neuropathy had affected a maximum of 686 (14.12%) followed by retinopathy (2.34%) and nephropathy (1.81%). Among the available 11 strengths, the glimepiride 2 mg and metformin 500 mg combination were most widely prescribed in 1297 (26.69%), followed by glimepiride 1 mg and metformin 500 mg in 1193 (24.57%) patients, and the preferred dosage pattern was twice a daily in 2665 (54.85%) T2DM patients. An age-wise prescription analysis showed that glimepiride and metformin combinations were the preferred choice for the management of diabetes across all the age groups. Conclusion The real-world evidence in the Indian clinical setting indicates that glimepiride and metformin fixed-dose combinations are widely used in the management in T2DM patients with comorbidities like hypertension, dyslipidemia, and diabetes complications. Glimepiride and metformin fixed-dose combinations are suitable for early as well as long-standing diabetes.