Optimization of Metformin in the GRADE Cohort: Effect on Glycemia and Body Weight

Metformin alleviates hyperkalemia-induced arrhythmia and cardiac injury in mice through decreasing SK2 and intracellular Ca2

BACKGROUND

Hyperkalemia is a critical electrolyte imbalance that can lead to life-threatening arrhythmia and cardiac injury. The potential protective role of metformin on acute hyperkalemia remains unclear. Our study aimed to investigate the mechanisms of metformin against hyperkalemia-induced arrhythmia and cardiac injury.

METHODS

We established hyperkalemia-induced arrhythmia model in vivo using intragastric KCl overload in mice, and followed by low- or high-dose metformin or insulin to evaluate cardiac electrocardiography (ECG), cardiac injury, and the regulation of key potassium channels. Additionally, we cultured HL-1 cells under varying potassium concentration, followed by treatment with insulin or metformin to assess the cell viability, apoptosis, the regulation of key potassium channels and intracellular and extracellular calcium (Ca2+) dynamics.

KEY FINDINGS

Our study demonstrates that both metformin and insulin have protective effects against hyperkalemia-induced arrhythmia. Notably, metformin significantly reversed the expression of Kv4.2 and SK2 channels, which are critical for maintaining normal cardiac electrical activity. Furthermore, metformin improved cardiomyocyte viability and reduced apoptosis in hyperkalemic conditions. Our findings also reveal that metformin increased serum Ca2+ levels and reduced intracellular Ca2+ levels, which is associated with the upregulation of parathyroid hormone (PTH). These results suggest that metformin exerts its protective effects through distinct mechanisms compared to insulin.

SIGNIFICANCE

These findings have important implications for the management of hyperkalemia, particularly in patients with underlying insulin resistance or those who cannot tolerate insulin therapy. By demonstrating the protective effects of metformin, our study opens new avenues for therapeutic intervention and further research into the role of metformin in cardiac protection.

Sedentary Lifestyles and a Hypercaloric Diets During Middle Age, are Binomial Conducive to Fatal Progression, That is Counteracted by the Hormetic Treatment of Exercise, Metformin, and Tert-Butyl Hydroquinone: An Analysis of Female Middle-Aged Rat Liver Mitochondria

The world's population continuous to shift towards older, less active and more sedentary lifestyles especially during middle age. In addition consumption of high-caloric diets, increases the risk of metabolic and cardiovascular afflictions. Developing clinical strategies to mitigate those health complications represent a difficult challenge. Our group has previously shown that combining metformin (MTF) and tert-butyl hydroquinone (tBHQ) treatments, in addition to exercise, partially prevents liver damage associated with obesity. Hence, we evaluated the role of exercise in combination with MTF and tBHQ (triple-treatment) to counteract mitochondrial damage in the liver from obese middle-aged female rats. Animals were fed a high-fat diet (HFD) starting at 21 days till 15 months of age. The treated groups performed a Fartlek-type exercise 5 days/week for 30 min/session. MTF and tBHQ were administered at a dose of 250 mg/kg/day, and 10 mg/kg/day, respectively, for 7 days/month from 10 to 15 months of age. Triple-treatment therapeutic approach promoted animal survival, and increased AMPK and PGC1α expression. Treatments increased mitochondrial ATP synthesis and OXPHOS complexes activities, recovered membrane potential, and decreased ROS production. In summary, exercise in combination with intermittent tBHQ and MTF treatments proved to be an excellent intervention to prevent mitochondrial damage caused by HFD.

Combination of Metformin and Epigallocatechin-3-Gallate Lowers Cortisol, 11β-Hydroxysteroid Dehydrogenase Type 1, and Blood Glucose Levels in Sprague Dawley Rats with Obesity and Diabetes

Background

The combined effects of metformin and epigallocatechin-3-gallate (EGCG) on cortisol, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), and blood glucose levels have not been investigated. This study evaluated the effectiveness of combining EGCG with metformin in regulating those levels in a rat model of diet-induced diabetes and obesity.

Methods

Thirty diabetic and obese rats on a high-fat diet were treated daily for 28 days with EGCG (100 mg/kg of body weight/day), metformin (200 mg/kg of body weight/day), or both. Control groups comprised lean rats, untreated obese diabetic rats, and metformin-only-treated rats. Blood samples were collected to measure cortisol and fasting blood glucose (FBG) levels and liver tissue samples were examined for 11β-HSD1 levels.

Results

Rats receiving combination therapy had significantly reduced cortisol levels (from 36.70±15.13 to 31.25±7.10 ng/mL) compared with the untreated obese diabetic rats but not the rats receiving monotherapy. Rats receiving combination therapy and EGCG monotherapy had significantly lower 11β-HSD1 levels compared with the untreated obese diabetic rats (92.68±10.82 and 93.74±18.11 ng/L vs. 120.66±14.00 ng/L). Combination therapy and metformin monotherapy significantly reduced FBG levels (440.83±133.30 to 140.50±7.36 mg/dL and 480.67±86.32 to 214.17±102.78 mg/dL, respectively) by approximately 68.1% and 55.4% compared with rats receiving EGCG monotherapy and untreated obese diabetic rats.

Conclusion

Combining EGCG with metformin exhibited synergistic effects compared with monotherapy for managing diabetes, leading to improved outcomes in reduction of baseline cortisol levels along with reduction in 11β-HSD1 and blood glucose levels.

Targeting macrophage polarization as a promising therapeutic strategy for the treatment of osteoarthritis

Osteoarthritis (OA) is a chronic osteoarthropathy characterized by the progressive degeneration of articular cartilage and synovial inflammation. Early OA clinical treatments involve intra-articular injection of glucocorticoids, oral acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), which are used for anti-inflammation and pain relief. However, long-term use of these agents will lead to inevitable side effects, even aggravate cartilage loss. At present, there are no disease-modifying OA drugs (DMOADs) yet approved by regulatory agencies. Polarization regulation of synovial macrophages is a new target for OA treatment. Inhibiting M1 polarization and promoting M2 polarization of synovial macrophages can alleviate synovial inflammation, relieve joint pain and inhibit articular cartilage degradation, which is a promising strategy for OA treatment. In this study, we describe the molecular mechanisms of macrophage polarization and its key role in the development of OA. Subsequently, we summarize the latest progress of strategies for OA treatment through macrophage reprogramming, including small molecule compounds (conventional western medicine and synthetic compounds, monomer compounds of traditional Chinese medicine), biomacromolecules, metal/metal oxides, cells, and cell derivatives, and interprets the molecular mechanisms, hoping to provide some information for DMOADs development.

Metformin attenuates osteoarthritis by targeting chondrocytes, synovial macrophages and adipocytes

OBJECTIVE

To investigate the therapeutic effect and mechanism of metformin on knee osteoarthritis (OA) in normal diet (ND) mice or high-fat diet (HFD)-induced obese mice.

METHODS

Destabilization of the medial meniscus surgery was performed in ND mice or HFD mice, and metformin was administrated in drinking water or not. The changes of OA joint structure, infiltration and polarization of synovial macrophages and circulating and local levels of leptin and adiponectin were evaluated. In vitro, the effects of metformin on chondrocytes and macrophages, and of conditioned mediums derived from mouse abdominal fat on murine chondrogenic cell line ATDC5 and murine macrophage cell line RAW264.7, were detected.

RESULTS

Metformin showed protective effects on OA, characterized by reductions on OARSI score (2.00, 95% CI [1.15-2.86] for ND mice and 3.17, 95% CI [2.37-3.96] for HFD mice) and synovitis score (1.17, 95% CI [0.27-2.06] for ND mice and 2.50, 95% CI [1.49-3.51] for HFD mice) after 10 weeks of treatment, and the effects were more significant in HFD mice than in ND mice. Mechanistically, in addition to decreasing apoptosis and matrix-degrading enzymes expression in chondrocytes as well as infiltration and pro-inflammatory differentiation of synovial macrophages, metformin reduced leptin secretion by adipose tissue in HFD mice.

CONCLUSIONS

Metformin protects against knee OA which could be through reducing apoptosis and catabolism of chondrocytes, and suppressing infiltration and pro-inflammatory polarization of synovial macrophages. For obese mice, metformin has a greater protective effect in knee OA additionally through reducing leptin secretion from adipose tissue.

Glycaemic control of Asian patients with type-2 diabetes mellitus on tiered up-titration of metformin monotherapy: A one-year real-world retrospective longitudinal study in primary care

AIMS

To determine the glycaemic control and associated factors among patients with type-2 diabetes mellitus on tiered metformin monotherapy over one-year.

METHODS

Adult Asian patients on metformin monotherapy with tiered dosage up-titration (low < 500 mg/day; medium 500-<1000 mg/day and high ≥ 1000 mg/day) are divided into four sub-cohorts based on their baseline HbA1c < 7%(C_<7); 7%-<8%(C_7-<8); 8%-<9%(C_8-<9) and ≥ 9%(C_≥9). The HbA1c absolute reduction, time to reach glycaemic control (HbA1c < 7%), and time from glycaemic control to failure (HbA1c ≥ 7%) after the dosage up-titration were the outcomes.

RESULTS

Among 5503 eligible patients (mean age = 64.9 years, 45.6% males and 74.6% Chinese), the HbA1c absolute reduction after the up-titration at three months are 0%, 0.4%-0.6%, 0.8%-1.2% and 2.0%-2.1% for C_<7, C_7-<8, C_8-<9 and C_≥9 respectively. The median time (months) to attain glycaemic control for low, medium and high dosage up-titration were 4, 3, 3(C_7-<8); 12, 7, 4(C_8-<9); NA, 7, 7(C_≥9). Within twelve months after the goal attainment, 36.2%(C_<7), 48.8%(C_7-<8), 52.7%(C_8-<9) and 45.3%(C_≥9) of patients had treatment failure.

CONCLUSIONS

The results show that the baseline HbA1c and tiered metformin dosage up-titration are associated with disproportionate HbA1c reduction, time to glycaemic control and time from glycaemic control to failure.

Contrasting Three Non-hypoglycemic Antidiabetic Drug Effects on Glycemic Control in Newly Diagnosed Type II Diabetes Mellitus: An Experimental Study

BACKGROUND: Diabetes mellitus (DM) type 2 is the most public chronic, metabolic illness whose prevalence is quickly becoming high international. Insulin resistance, the essential metabolic problem leads to the development of DM type 2, is seen in about 90% of patients. AIM: The study’s aim was to compare the efficacy of three antidiabetic drugs on glycated hemoglobin. METHOD: A cross-sectional comparative study for newly diagnosed type II diabetic patients were assigned randomly into one of three conditions: Group I: Metformin consuming patients, Group II: Pioglitazone consuming patients, and Group III: Vildagliptin consuming patients. All patients were newly diagnosed. For all of them, baseline glycated hemoglobin was requested. After that, random assignment was carried out. After 3 months, glycated hemoglobin was checked and compared. RESULTS: Participants were distributed randomly into 27.9% metformin taking participants, 31.1% pioglitazone taking, and 41% vildagliptin taking patient. Findings suggested significant difference between Groups I and III (p =). Likewise, significant difference was seen between Groups II and III (p =). However, Groups I and II have comparable effects (p =). Indeed, all groups had shown significant efficacy on HbA1c. CONCLUSION: Metformin, pioglitazone, and vildagliptin had shown significant impact on HbA1c with variable degree: Metformin and pioglitazone had shown comparably similar efficacy that was exerted more significant impact on HbA1c than vildagliptin does.

Current Options and Future Directions for NAFLD and NASH Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with a broad spectrum ranging from simple steatosis to advanced stage of nonalcoholic steatohepatitis (NASH). Although there are many undergoing clinical trials for NAFLD treatment, there is no currently approved treatment. NAFLD accounts as a major causing factor for the development of hepatocellular carcinoma (HCC), and its incidence rises accompanying the prevalence of obesity and diabetes. Reprogramming of antidiabetic and anti-obesity medicine is a major treatment option for NAFLD and NASH. Liver inflammation and cellular death, with or without fibrosis account for the progression of NAFLD to NASH. Therefore, molecules and signaling pathways involved in hepatic inflammation, fibrosis, and cell death are critically important targets for the therapy of NAFLD and NASH. In addition, the avoidance of aberrant infiltration of inflammatory cytokines by treating with CCR antagonists also provides a therapeutic option. Currently, there is an increasing number of pre-clinical and clinical trials undergoing to evaluate the effects of antidiabetic and anti-obesity drugs, antibiotics, pan-caspase inhibitors, CCR2/5 antagonists, and others on NAFLD, NASH, and liver fibrosis. Non-invasive serum diagnostic markers are developed for fulfilling the need of diagnostic testing in a large amount of NAFLD cases. Overall, a better understanding of the underlying mechanism of the pathogenesis of NAFLD is helpful to choose an optimized treatment.

Real-World Clinical Experience on the Usage of High-Dose Metformin (1500-2500 mg/day) in Type 2 Diabetes Management

Background:

To evaluate the clinical characteristics, treatment patterns, and clinical effectiveness and safety of high doses of metformin (1500-2500 mg/day) in Indian adults with type 2 diabetes mellitus (T2DM).

Materials and methods:

A retrospective, multicentric (n = 241), real-world study included patients with T2DM (aged >18 years) receiving high doses of metformin. Details were retrieved from patient’s medical records.

Results:

Out of 5695 patients, 62.7% were men with median age was 50.0 years. Hypertension (67.5%) and dyslipidemia (48.7%) were the prevalent comorbidities. Doses of 2000 mg (57.4%) and 1500 mg (29.1%) were the most commonly used doses of metformin and median duration of high-dose metformin therapy was 24.0 months. Metformin twice daily was the most frequently used dosage pattern (94.2%). Up-titration of doses was done in 96.8% of patients. The mean HbA1c levels were significantly decreased post-treatment (mean change: 1.08%; P < .001). The target glycemic control was achieved in 91.2% patients. A total of 83.0% had decreased weight. Adverse events were reported in 156 patients. Physician global evaluation of efficacy and tolerability showed majority of patients on a good to excellent scale (98.2% and 97.7%).

Conclusion:

Clinical effectiveness and safety of a high-dose metformin was demonstrated through significant improvement in HbA1c levels and weight reduction.

Should metformin remain the first-line therapy for treatment of type 2 diabetes?

Metformin is a biguanide that is used as first-line treatment of type 2 diabetes mellitus and is effective as monotherapy and in combination with other glucose-lowering medications. It is generally well-tolerated with minimal side effects and is affordable. Although the safety and efficacy of metformin have been well-established, there is discussion regarding whether metformin should continue to be the first choice for therapy as other anti-hyperglycemic medications exhibit additional advantages in certain populations. Despite a long-standing history of metformin use, there are limited cardiovascular outcomes data for metformin. Furthermore, the available studies fail to provide strong evidence due to either small sample size or short duration. Recent data from glucagon-like peptide-1 receptor agonist and sodium-glucose cotransporter-2 inhibitor cardiovascular and renal outcomes trials demonstrated additional protection from diabetes complications for some high-risk patients, which has impacted the guidelines for diabetes management. Post-hoc analyses comparing hazard ratios for participants taking metformin at baseline versus not taking metformin are inconclusive for these two groups. There are no data to suggest that metformin should not be initiated soon after the diagnosis of diabetes. Furthermore, the initiation of newer glycemic-lowering medications with cardiovascular benefits should be considered in high-risk patients regardless of glycemic control or target HbA1c. However, cost remains a major factor in determining appropriate treatment.