Recommendations for Practical Use of Metformin, a Central Pharmacological Therapy in Type 2 Diabetes

Comparative Effects of GLP-1 Receptor Agonists and Metformin on Glaucoma Risk in Type 2 Diabetes Patients

PURPOSE

To compare effects of glucagon-like peptide-1 (GLP-1) receptor agonists and metformin on the risk of primary open-angle glaucoma (POAG), ocular hypertension, and the need for first-line glaucoma treatments in patients with type 2 diabetes.

DESIGN

A retrospective cohort study was conducted using electronic medical records (EMR) data from the from an international electronic health record network, covering a period from May 2006 to May 2024.

PARTICIPANTS

Patients diagnosed with type 2 diabetes mellitus (T2DM) who were treated with either GLP-1 receptor agonists or metformin.

METHODS

Data from 120 healthcare organizations across 17 countries were analyzed. Patient outcomes were assessed at 1, 2, and 3 years. Propensity score matching (PSM) was used to balance covariates such as demographics, comorbidities, and medication usage. Risk ratios (RR) with 95% confidence intervals (CI) were calculated.

MAIN OUTCOME MEASURES

Incidence of POAG, ocular hypertension, and the need for first-line treatments including beta-blockers, prostaglandin analogues, brimonidine, brinzolamide, dorzolamide, netarsudil, and laser trabeculoplasty.

RESULTS

After PSM, both groups included 61,998 patients at the 1-year follow-up, 27,414 at the 2-year follow-up, and 14,100 at the 3-year follow-up. Patients treated with GLP-1 receptor agonists had a significantly decreased risk of developing POAG compared to those on metformin at 1 year (RR 0.59, 95% CI 0.39-0.88), 2 years (RR 0.50, 95% CI 0.32-0.78), and 3 years (RR 0.59, 95% CI 0.37-0.94). Similar protective effects were observed for ocular hypertension with risk reductions of 56% at 1 year (RR 0.44, 95% CI 0.31-0.62), 57% at 2 years (RR 0.43, 95% CI 0.30-0.62), and 49% at 3 years (RR 0.51, 95% CI 0.34-0.75). The risk of first-line therapy initiation was also lower in the GLP-1 receptor agonists group at 1 year (RR 0.63, 95% CI 0.53-0.74), 2 years (RR 0.71, 95% CI 0.59-0.85), and 3 years (RR 0.75, 95% CI 0.62-0.91).

CONCLUSIONS

GLP-1 receptor agonists are associated with a significantly lower incidence of POAG, ocular hypertension, and the need for first-line glaucoma treatments compared to metformin in patients with type 2 diabetes. These findings highlight the potential ocular benefits of GLP-1 receptor agonists and their expanding role in the clinical management of diabetic patients.

The Association between Vitamin D Status and the Impact of Metformin on Hypothalamic-Pituitary-Thyroid Axis Activity in Women with Subclinical Hypothyroidism

Metformin inhibits enhanced secretion of anterior pituitary hormones. Its impact on prolactin and gonadotropin concentrations is absent in individuals with hypovitaminosis D. The aim of this prospective cohort study was to investigate whether vitamin D status determines the effect of metformin on hypothalamic-pituitary-thyroid axis activity in levothyroxine-naïve women. The study included three groups of women of reproductive age with subclinical non-autoimmune hypothyroidism, which were matched for age, thyroid-stimulating hormone (TSH) concentration, and insulin sensitivity: untreated women with vitamin D deficiency/insufficiency (group A), women effectively supplemented with exogenous calciferol (group B), and untreated women with normal 25-hydroxyvitamin D concentrations (25OHD) (group C). Owing to concomitant type 2 diabetes or prediabetes, all subjects were treated with metformin. Concentrations of 25OHD, TSH, total and free thyroid hormones, glucose, insulin, glycated hemoglobin (HbA1c), prolactin, and peripheral markers of thyroid hormone action were assayed before metformin treatment and six months later. Based on hormone concentration, structure parameters of thyroid homeostasis were calculated. Except for 25OHD concentrations, there were no between-group differences in baseline values of the measured variables. Metformin reduced glucose, the homeostatic model assessment 1 of insulin resistance ratio (HOMA1-IR), and HbA1c in all study group, but these effects were less pronounced in group A than in the remaining groups. The reduction in TSH and Jostel's index was observed only in groups B and C, and its degree correlated with baseline TSH concentrations, baseline 25OHD concentrations, and the degree of improvement in HOMA1-IR. The drug did not affect circulating levels of 25OHD, free and total thyroid hormones, prolactin, other structure parameters of thyroid homeostasis, and markers of thyroid hormone action. The obtained results allow us to conclude that low vitamin D status in young women mitigates the impact of metformin on thyrotroph secretory function.

Metformin-Induced Nightmares: An Uncommon Event

Metformin is well-known in the treatment of type 2 diabetes mellitus (DM). Metformin has become a drug of choice due to its affordability, cost-effectiveness, and established safety record. It primarily works by inhibiting hepatic gluconeogenesis. Common side effects include gastrointestinal issues, with rare complications, such as lactic acidosis and vitamin B12 malabsorption. This study discussed a 72-year-old male with type 2 DM who experienced recurrent nightmares upon initiating metformin, which ceased after discontinuation. The mechanism of metformin-associated nightmares remains poorly understood. Despite metformin's benefits, this case highlights the importance of recognizing rare adverse effects like nightmares, which can significantly impact patients' quality of life.

Skin-Related Adverse Reactions Induced by Oral Antidiabetic Drugs-A Review of Literature and Case Reports

Type 2 diabetes (T2DM) is a chronic metabolic disease with a steadily increasing prevalence worldwide. Diabetes affects the function of many organs, including the skin. Pharmacotherapy for T2DM is mainly based on oral hypoglycemic drugs. The therapeutic strategy is chosen taking into account the individual patient's characteristics, among other comorbidities. Antidiabetic drugs can induce cutaneous adverse reactions (CADRs) ranging in severity from mild erythema to serious disorders such as DRESS or Stevens-Johnson syndrome. CADRs can result from hypersensitivity to the drug but can also be related to the mechanism of action of the drug or cross-reactivity with drugs of similar structure. This paper reviews CADRs induced by oral antidiabetic drugs, considering their dermatological manifestations and possible pathomechanisms. Particular attention was paid to specific dermatological conditions such as dipeptidylpeptidase 4 inhibitor-associated bullous pemphigoid or Fournier's gangrene associated with sodium-glucose cotransporter 2 inhibitor therapy. Knowledge of the dermatological manifestations of CADRs is important in clinical practice. Recognition of a skin lesion resulting from an adverse drug reaction allows for appropriate management, which in this case is primarily related to drug discontinuation. This is particularly important in the treatment of T2DM since this disease has a high prevalence in the elderly, who are at higher risk of adverse drug reactions.

A case of metformin-associated lactic acidosis with cardiogenic and vasoplegic shock supported by ECPella

Metfomin-associated lactic acidosis (MALA) is a rare but life-threatening complication of metformin use. We present a case of MALA with concurrent cardiogenic and vasoplegic shock which was successfully supported by ECPella (concurrent use of VA-ECMO and Impella). Early recognition, aggressive hemodynamic support with ECPella and early hemodialysis can be life-saving. Monitoring of both lactate and SvO2 trends can help understand the response to treatment.