Metformin Exposure Research Articles

The association between prescribed oral anti-diabetic medication for type 2 diabetes mellitus and skin cancer risk: a systematic review and meta-analysis.

We conducted a systematic review to determine if there is a significant association between prescribed oral antidiabetic medication and the risk of developing skin cancer [basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC) and melanoma] in people with type 2 diabetes. Fourteen studies were included. Risk of bias ranged from low to moderate. Overall, no statistically significant association was identified between antidiabetic medication use and skin cancer. There was a dose–response relationship, with higher doses of metformin and rosiglitazone associated with a greater decrease in skin cancer risk than lower doses. The risk of BCC and cSCC reduced following metformin and rosiglitazone exposure vs. nonusers.

Characterizing placental NLRP3 inflammasome and lipidome dynamics: Insights from glucose, metformin, and LPS exposure in placental explants

Characterizing placental NLRP3 inflammasome and lipidome dynamics: Insights from glucose, metformin, and LPS exposure in placental explants

Metformin and small for gestational age babies: findings of a randomised placebo-controlled clinical trial of metformin in gestational diabetes (EMERGE).

Gestational diabetes mellitus (GDM) is associated with adverse perinatal outcomes because of suboptimal glucose management and glucose control and excessive weight gain. Metformin can offset these factors but is associated with small for gestational age (SGA) infants. We sought to identify risk factors for SGA infants, including the effect of metformin exposure on SGA status. In this prespecified secondary analysis of the EMERGE trial, which evaluated the effectiveness of metformin vs placebo in treating GDM and found reduced gestational weight gain and longer time to insulin initiation with metformin use, we included women with a live-born infant and known infant birthweight and gestational age at delivery. We compared the numbers of SGA infants in both groups and explored baseline predictive factors to help identify those at highest risk of delivering an SGA infant. Baseline maternal characteristics were similar between SGA and non-SGA pregnancies. On multivariable-adjusted regression, no baseline maternal variables were associated with SGA status. Mothers of SGA infants were more likely to develop pre-eclampsia or gestational hypertension (18.2% vs 2.0%, p=0.001; 22.7% vs 5.4%, p=0.005, respectively); after multivariable adjustment, pre-eclampsia was positively associated with SGA status). Among SGA pregnancies, important perinatal outcomes including preterm birth, Caesarean delivery and neonatal care unit admission did not differ between the metformin and placebo groups (20.0% vs 14.3%, p=1.00; 50.0% vs 28.6%, p=0.25; 13.3% vs 42.9%, p=0.27, respectively). Pre-eclampsia was strongly associated with SGA infants. Metformin-exposed SGA infants did not display a more severe SGA phenotype than infants treated with placebo. Clinical Trials.gov NCT02980276; EudraCT number: 2016-001644-19.

Synergistic Effects of Glutamine Deprivation and Metformin in Acute Myeloid Leukemia.

The metabolic reprogramming of acute myeloid leukemia (AML) cells is a compensatory adaptation to meet energy requirements for rapid proliferation. This study aimed to examine the synergistic effects of glutamine deprivation and metformin exposure on AML cells. SKM-1 cells (an AML cell line) were subjected to glutamine deprivation and/or treatment with metformin or bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES, a glutaminase inhibitor) or cytarabine. Cell viability was detected by Cell Counting Kit-8 (CCK-8) assay, and cell apoptosis and reactive oxygen species (ROS) by flow cytometry. Western blotting was conducted to examine the levels of apoptotic proteins, including cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP). Moreover, the human long noncoding RNA (lncRNA) microarray was used to analyze gene expression after glutamine deprivation, and results were confirmed with quantitative RT-PCR (qRT-PCR). The expression of metallothionein 2A (MT2A) was suppressed using siRNA. Cell growth and apoptosis were further detected by CCK-8 assay and flow cytometry, respectively, in cells with MT2A knockdown. Glutamine deprivation or treatment with BPTES inhibited cell growth and induced apoptosis in SKM-1 cells. The lncRNA microarray result showed that the expression of MT family genes was significantly upregulated after glutamine deprivation. MT2A knockdown increased apoptosis, while proliferation was not affected in SKM-1 cells. In addition, metformin inhibited cell growth and induced apoptosis in SKM-1 cells. Both glutamine deprivation and metformin enhanced the sensitivity of SKM-1 cells to cytarabine. Furthermore, the combination of glutamine deprivation with metformin exhibited synergistic antileukemia effects on SKM-1 cells. Targeting glutamine metabolism in combination with metformin is a promising new therapeutic strategy for AML.

No dose adjustment of metformin or substrates of organic cation transporters (OCT)1 and OCT2 and multidrug and toxin extrusion protein (MATE)1/2K with fostemsavir coadministration based on modeling approaches.

Fostemsavir is an approved gp120-directed attachment inhibitor and prodrug for the treatment of human immunodeficiency virus type 1 infection in combination with other antiretrovirals (ARVs) in heavily treatment-experienced adults with multi-drug resistance, intolerance, or safety concerns with their current ARV regimen. Initial invitro studies indicated that temsavir, the active moiety of fostemsavir, and its metabolites, inhibited organic cation transporter (OCT)1, OCT2, and multidrug and toxin extrusion transporters (MATEs) at tested concentration of 100 uM, although risk assessment based on the current Food and Drug Administration invitro drug-drug interaction (DDI) guidance using the mechanistic static model did not reveal any clinically relevant inhibition on OCTs and MATEs. However, a DDI risk was flagged with EMA static model predictions. Hence, a physiologically based pharmacokinetic (PBPK) model of fostemsavir/temsavir was developed to further assess the DDI risk potential of OCT and MATEs inhibition by temsavir and predict changes in metformin (a sensitive OCT and MATEs substrate) exposure. No clinically relevant impact on metformin concentrations across a wide range of temsavir concentrations was predicted; therefore, no dose adjustment is recommended for metformin when co-administered with fostemsavir.

Metformin monotherapy versus predominantly older non-metformin antidiabetic medications for cerebrovascular risk in early type 2 diabetes management.

Choosing the initial treatment for type 2 diabetes (T2D) is pivotal, requiring consideration of solid clinical evidence and patient characteristics. Despite metformin's historical preference, its efficacy in preventing cerebrovascular events lacked empirical validation. This study aimed to evaluate the associations between first-line monotherapy (metformin or non-metformin antidiabetic medications) and cerebrovascular complications in patients with T2D without diabetic complications. We analysed 9090 patients with T2D without complications who were prescribed either metformin or non-metformin medications as initial therapy. Propensity score matching ensured group comparability. Cox regression analyses, stratified by initial metformin use, assessed cerebrovascular disease risk, adjusting for multiple covariates and using competing risk analysis. Metformin exposure was measured using cumulative defined daily doses. Metformin users had a significantly lower crude incidence of cerebrovascular diseases compared with non-users (p < .0001). Adjusted hazard ratios (aHRs) consistently showed an association between metformin use and a lower risk of overall cerebrovascular diseases (aHRs: 0.67-0.69) and severe events (aHRs: 0.67-0.69). The association with reduced risk of mild cerebrovascular diseases was significant across all models (aHRs: 0.73-0.74). Higher cumulative defined daily doses of metformin correlated with reduced cerebrovascular risk (incidence rate ratio: 0.62-0.94, p < .0001), indicating a dose-dependent effect. Metformin monotherapy is associated with a reduced risk of cerebrovascular diseases in early-stage T2D, highlighting its dose-dependent efficacy. However, the observed benefits might also be influenced by baseline differences and the increased risks associated with other medications, such as sulphonylureas. These findings emphasize the need for personalized diabetes management, particularly in mitigating cerebrovascular risk in early T2D stages.

Metformin augments major cytoplasmic organization except for spindle organization in oocytes cultured under hyperglycemic and hyperlipidemic conditions: An in vitro study

The present study aimed to investigate the role of antidiabetic drug metformin on the cytoplasmic organization of oocytes. Germinal vesicle (GV) stage oocytes were collected from adult female Swiss albino mice and subjected to in vitro maturation (IVM) in various experimental groups- control, vehicle control (0.3% ethanol), metformin (50 μg/mL), high glucose and high lipid (HGHL, 10 mM glucose; 150 μM palmitic acid; 75 μM stearic acid and 200 μM oleic acid in ethanol), and HGHL supplemented with metformin. The metaphase II (MII) oocytes were analyzed for lipid accumulation, mitochondrial and endoplasmic reticulum (ER) distribution pattern, oxidative and ER stress, actin filament organization, cortical granule distribution pattern, spindle organization and chromosome alignment. An early polar body extrusion was observed in the HGHL group. However, the maturation rate at 24 h did not differ significantly among the experimental groups compared to the control. The HGHL conditions exhibited significantly higher levels of oxidative stress, ER stress, poor actin filament organization, increased lipid accumulation, altered mitochondrial distribution, spindle abnormalities, and chromosome misalignment compared to the control. Except for spindle organization, supplementation of metformin to the HGHL conditions improved all the parameters (non-significant for ER and actin distribution pattern). These results show that metformin exposure in the culture media helped to improve the hyperglycemia and hyperlipidemia-induced cytoplasmic anomalies except for spindle organization. Given the crucial role of spindle organization in proper chromosome segregation during oocyte maturation and meiotic resumption, the implications of metformin's limitations in this aspect warrant careful evaluation and further investigation.

Paternal Use of Metformin During the Sperm Development Period Preceding Conception and Risk for Major Congenital Malformations in Newborns.

Metformin is the most used oral antidiabetic medication. Despite its established safety profile, it has known antiandrogenic and epigenetic modifying effects. This raised concerns about possible adverse developmental effects caused by genomic alterations related to paternal use of metformin during the spermatogenesis period preceding conception. To assess the potential adverse intergenerational effect of metformin by examining the association between paternal metformin use during spermatogenesis and major congenital malformations (MCMs) in newborns. Nationally representative cohort study. A large Israeli health fund. 383 851 live births linked to fathers and mothers that occurred in 1999 to 2020. MCMs and parental cardiometabolic conditions were ascertained using clinical diagnoses, medication dispensing information, and laboratory test results. The effect of metformin use on MCMs was estimated using general estimating equations, accounting for concurrent use of other antidiabetic medications and parental cardiometabolic morbidity. Compared with unexposed fathers, the prevalence of cardiometabolic morbidity was substantially higher among fathers who used metformin during spermatogenesis, and their spouses. Whereas the crude odds ratio (OR) for paternal metformin exposure in all formulations and MCMs was 1.28 (95% CI, 1.01 to 1.64), the adjusted OR was 1.00 (CI, 0.76 to 1.31). Within specific treatment regimens, the adjusted OR was 0.86 (CI, 0.60 to 1.23) for metformin in monotherapy and 1.36 (CI, 1.00 to 1.85) for metformin in polytherapy, a treatment that was more common in patients with more poorly controlled diabetes. Laboratory test results for hemoglobin A1c to assess underlying diabetes severity were available only for a subset of the cohort. Paternal use of metformin in monotherapy does not increase the risk for MCMs. Association for metformin in polytherapy could potentially be explained by worse underlying parental cardiometabolic risk profile. None.

Regulation of intracellular process by two-component systems: Exploring the mechanism of plasmid-mediated conjugative transfer

Plasmid-mediated conjugative transfer facilitates the dissemination of antibiotic resistance, yet the comprehensive regulatory mechanisms governing this process remain elusive. Herein, we established pure bacteria and activated sludge conjugation system to investigate the regulatory mechanisms of conjugative transfer, leveraging metformin as an exogenous agent. Transcriptomic analysis unveiled that substantial upregulation of genes associated with the two-component system (e.g., AcrB/AcrA, EnvZ/Omp, and CpxA/CpxR) upon exposure to metformin. Furthermore, downstream regulators of the two-component system, including reactive oxygen species (ROS), cytoplasmic membrane permeability, and adenosine triphosphate (ATP) production, were enhanced by 1.7, 1.4 and 1.1 times, respectively, compared to the control group under 0.1 mg/L metformin exposure. Moreover, flow sorting and high-throughput sequencing revealed increased microbial community diversity among transconjugants in activated sludge systems. Notably, the antibacterial potential of human pathogenic bacteria (e.g., Bacteroides, Escherichia-Shigella, and Lactobacillus) was augmented, posing a potential threat to human health. Our findings shed light on the spread of antibiotic resistance bacteria and assess the ecological risks associated with plasmid-mediated conjugative transfer in wastewater treatment systems.

Metformin exposure during pregnancy and lactation affects offspring's long-term body weight and adipose tissue mass independent of the maternal metabolic state

The increasing prevalence of obesity, type 2 diabetes mellitus (T2DM), and gestational diabetes (GDM) among pregnant women has risen dramatically worldwide. The antihyperglycemic drug metformin is the most common drug for T2DM treatment in non-pregnant individuals; nevertheless, it is increasingly being used for diabetes-complicated pregnancies. Studies on the long-term metabolic effects of this drug in offspring remain scarce. This work aimed to determine the effect of metformin exposure during pregnancy and lactation on the offspring of a model of diet-induced maternal hyperglycemia.Cohorts of pregnant mice were fed a 46% fat diet (HFD) or a control standard diet (SD). A group of dams were exposed to metformin during pregnancy and lactation. After weaning, the offspring were fed SD for 8 weeks and then challenged with a 46% HFD after puberty for 12 weeks. Irrespective of the maternal diet, offspring of metformin-exposed mothers had a lower body weight and reduced inguinal white adipose tissue (iWAT) mass after HFD challenge. This was associated with increased expression of Pparg, Fabp4, Glut4, Srebp1, and Fasn in the iWAT during adulthood in the metabolically impaired dams exposed to metformin, suggesting increased adipogenesis and de novo lipogenesis. Increased expression of Fasn associated with decreased methylation levels at its promoter and proximal coding region in the iWAT was found. These results suggest that metformin modulates gene expression levels by epigenetic mechanisms in maternal metabolic-impaired conditions.

Metformin use in pregnancy: What about long-term effects in offspring?

Metformin use in pregnancy is increasing worldwide. Unlike insulin, metformin crosses the placenta. Consequently, maternal and fetal concentrations are comparable. Teratogenic effects are not reported, nor are adverse pregnancy outcomes. Reduced risk of hypertensive disorders, hypoglycemia, and macrosomia are potential benefits, together with lower gestational weight gain. Although metformin has been prescribed for pregnant women during the last 40 years, long-term data regarding offspring outcomes are still lacking. Independent of maternal glycemic control, recent meta-analyses report lower birthweight but accelerated postnatal growth and higher body mass index in metformin-exposed children. The longest follow-up study of placebo-controlled metformin exposure in utero found an increased prevalence of central adiposity and obesity among children 5-10 years old. Recently, a Danish study reported a threefold increased risk of genital anomalies in boys, whose fathers used metformin around the time of conception. This commentary addresses the current controversies on metformin use in pregnancy.

Effect of Metformin on Sertoli Cell Fatty Acid Metabolism and Blood-Testis Barrier Formation.

Sertoli cells (SCs) are essential to maintaining germ cell development. Metformin, the main pharmacologic treatment for pediatric type 2 diabetes, is administered to children during SC maturation. The present study aimed to analyze whether metformin affects SC energy metabolism and blood-testis barrier (BTB) integrity. Primary SC cultures were used for the in vitro studies. In vivo effects were studied in Sprague-Dawley rats treated with 200 mg/kg metformin from Pnd14 to Pnd30. Metformin decreased fatty acid oxidation and increased 3-hydroxybutyrate production in vitro. Moreover, it decreased the transepithelial electrical resistance across the monolayer and induced ZO-1 redistribution, suggesting an alteration of cell junctions. In vivo, a mild but significant increase in BTB permeability and ZO-1 expression was observed in the metformin group, without changes in testicular histology and meiosis progression. Additionally, adult rats that received metformin treatment during the juvenile period showed no alteration in BTB permeability or daily sperm production. In conclusion, metformin exposure may affect BTB permeability in juvenile rats, but this seems not to influence spermatogenesis progression. Considering the results obtained in adult animals, it is possible to speculate that metformin treatment during the juvenile period does not affect testicular function in adulthood.

Effects of metformin on wild fathead minnows (Pimephales promelas) using in-lake mesocosms in a boreal lake ecosystem

Due to its widespread use for the treatment of Type-2 diabetes, metformin is routinely detected in surface waters globally. Laboratory studies have shown that environmentally relevant concentrations of metformin can adversely affect the health of adult fish, with effects observed more frequently in males. However, the potential risk to wild fish populations has yet to be fully elucidated and remains a topic of debate. To explore whether environmentally relevant metformin exposure poses a risk to wild fish populations, the present study exposed wild fathead minnows (Pimephales promelas) to 5 or 50 μg/L metformin via 2 m diameter in-lake mesocosms deployed in a natural boreal lake in Northern Ontario at the International Institute for Sustainable Development - Experimental Lakes Area (IISD-ELA). Environmental monitoring was performed at regular intervals for 8-weeks, with fish length, weight (body, liver and gonad), condition factor, gonadosomatic index, liver-somatic index, body composition (water and biomolecules) and hematocrit levels evaluated at test termination. Metabolic endpoints were also evaluated using liver, brain and muscle tissue, and gonads were evaluated histologically. Results indicate that current environmental exposure scenarios may be sufficient to adversely impact the health of wild fish populations. Adult male fish exposed to metformin had significantly reduced whole body weight and condition factor and several male fish from the high-dose metformin had oocytes in their testes. Metformin-exposed fish had altered moisture and lipid (decrease) content in their tissues. Further, brain (increase) and liver (decrease) glycogen were altered in fish exposed to high-dose metformin. To our knowledge, this study constitutes the first effort to understand metformin's effects on a wild small-bodied fish population under environmentally relevant field exposure conditions.

Metformin alters dendrite development and synaptic plasticity in rat cortical neurons

Synaptic plasticity is crucial as it dynamically molds the strength and connectivity of neural circuits, influencing learning, memory, and the development of neurological disorders. Metformin, a widely prescribed anti-diabetic medication, has been shown to readily cross the blood-brain barrier (BBB) and the placenta. However, its prolonged impact on neuronal morphology and functions remains underexplored. In this study, we investigated the influence of metformin on dendrite development and synaptic plasticity in embryonic brains and primary rat cortical neurons. Our findings reveal a negative modulation of dendrite development by metformin, as evidenced by altered dendritic arborization, impaired dendritic spine morphology and disruptions in synaptic plasticity, suggesting a potential link between metformin exposure and aberrations in neuronal connectivity. In addition, we extend our insights to the impact of maternal metformin exposure on embryonic brains, revealing a significant inhibition of dendrite development in E18.5 rat brains. In conclusion, this study adds to the expanding knowledge base on the non-metabolic effects of metformin, emphasizing the significance of assessing its potential influence on both neuronal structure and function. There is an urgent need for further investigations into the enduring impact of prolonged metformin administration on the structural and functional aspects of neurons.

Perturbations in the earthworm metabolite profile during a two-week exposure to metformin

Metformin is among the most prescribed pharmaceuticals in many countries, and as a result has shown up in biosolids derived from municipal wastewater treatment that are destined for land application. In humans taking metformin, the effects include reduced glucose uptake in the intestine, a reduction in gluconeogenesis, increased oxidation of fatty acids, and reduced fatty acid synthesis. The effects of metformin on soil-dwelling organisms are not well understood. This study tested the effects of metformin exposure (0, 10, 40, 160, 640 μg g−1) on the earthworm (E. fetida) at four time points (6 h, 2 d, 7 d, and 14 d) using GC-MS to reveal sub-lethal effects and elucidate potential modes of action for metformin. There were no mortalities observed, and earthworms exposed to the highest concentrations (160 and 640 μg g−1) gained weight relative to the control on days 7 and 14. Significant reductions on day 7 were observed for glucose and malic acid (consistent with a reduction in gluconeogenesis), and for palmitic and margaric acid (consistent with increased oxidation and reduced synthesis of fatty acids). Lactic acid ranked first and second among canonicals 1 and 2 respectively and led to significant differences in discriminant scores across concentration and time. Metabolite levels increased to equal or greater than the control on day 14, likely caused by reduced exposure as metformin is reported to be readily transformed by microorganisms under aerobic conditions. The observations were consistent with the known effects of metformin in humans, and suggests that a similar mode of action exists in earthworms.

Metformin exposure and the incidence of lactic acidosis in critically ill patients with T2DM: A retrospective cohort study.

The objective of this study was to investigate the correlation between metformin exposure and the incidence of lactic acidosis in critically ill patients. The patients with type 2 diabetes mellitus (T2DM) were included from Medical Information Mart for Intensive Care IV database (MIMIC-IV). The primary outcome was the incidence of lactic acidosis. The secondary outcomes were lactate level and in-hospital mortality. Propensity score matching (PSM) method was adopted to reduce bias of the confounders. The multivariate logistic regression was used to explore the correlation between metformin exposure and the incidence of lactic acidosis. Subgroup analysis and sensitivity analysis were used to test the stability of the conclusion. We included 4939 patients. There were 2070 patients in the metformin group, and 2869 patients in the nonmetformin group. The frequency of lactic acidosis was 5.7% (118/2070) in the metformin group and it was 4.3% (122/2869) in the nonmetformin group. There was a statistically significant difference between the two groups (P < 0.05). The lactate level in the metformin group was higher than in the nonmetformin group (2.78 ± 2.23 vs. 2.45 ± 2.24, P < 0.001). After PSM, the frequency of lactic acidosis (6.3% vs. 3.7%, P < 0.001) and lactate level (2.85 ± 2.38 vs. 2.40 ± 2.14, P < 0.001) were significantly higher in the metformin group compared with the nonmetformin group. In multivariate logistic models, the frequency of lactic acidosis was obviously increased in metformin group, and the adjusted odds ratio (OR) of metformin exposure was 1.852 (95% confidence interval (CI) = 1.298-2.643, P < 0.001). The results were consistent with subgroup analysis except for respiratory failure subgroup. Metformin exposure increased lactate level but did not affect the frequency of lactic acidosis in patients of respiratory failure with hypercapnia. However, the in-hospital mortality between metformin and nonmetformin group had no obvious difference (P = 0.215). In sensitivity analysis, metformin exposure showed similar effect as the original cohort. In critically ill patients with T2DM, metformin exposure elevated the incidence of lactic acidosis except for patients of respiratory failure with hypercapnia, but did not affect the in-hospital mortality.

Neonatal outcome following metformin-treated gestational diabetes mellitus: A population-based cohort study.

Neonatal hypoglycemia is a common complication associated with gestational diabetes and therefore relevant to consider in evaluations of maternal treatment. We aimed to investigate the risk of neonatal hypoglycemia in offspring exposed to metformin treatment alone (MT) or combined with insulin (MIT) in comparison with nutrition therapy alone (NT), and insulin treatment alone (IT). In addition, we investigated MT in comparison with MIT. Secondary outcomes included neonatal anthropometrics, respiratory morbidity, hyperbilirubinemia, 5-min Apgar score, and preterm birth. This Swedish population-based cohort included 16 181 women diagnosed with gestational diabetes, and their singleton offspring born in 2019-2021. We estimated risk as adjusted odds ratio (aOR) with 95% confidence interval (CI), using individual-level, linkage register-data in multivariable logistic regression models. In the main analysis, MT was associated with a lower risk of neonatal hypoglycemia vs NT (aOR 0.85, 95% CI: 0.74-0.96), vs MIT (0.74 [0.64-0.87]), and vs IT (0.47 [0.40-0.55]), whereas MIT was associated with a similar risk of neonatal hypoglycemia vs NT (1.14 [0.99-1.30]) and with lower risk vs IT (0.63 [0.53-0.75]). However, supplemental feeding rates were lower for NT vs pharmacological treatments (p < 0.001). In post hoc subgroup analyses including only exclusively breastfed offspring, the risk of neonatal hypoglycemia was modified and similar among MT and NT, and higher in MIT vs NT. Insulin exposure, alone or combined with metformin, was associated with increased risk of being large for gestational age. Compared with NT, exposure to any pharmacological treatment was associated with significantly lower risk of 5-min Apgar score < 4. All other secondary outcomes were comparable among the treatment categories. The risk of neonatal hypoglycemia appears to be comparable among offspring exposed to single metformin treatment and nutrition therapy alone, and the lower risk that we observed in favor of metformin is probably explained by a difference in supplemental feeding practices rather than metformin per se. By contrast, the lower risk favoring metformin exposure over insulin exposure was not explained by supplemental feeding. However, further investigations are required to determine whether the difference is an effect of metformin per se or mediated by other external factors.

Mitophagy as a potential mediator for the anti‐inflammatory effects of metformin in human retinal pigment epithelium cells

Aims/Purpose: Mitochondrial malfunction and subsequent excessive production of reactive oxygen species (ROS), deficient autophagy and chronic inflammation are associated with many age‐related diseases, including age‐related macular degeneration. In this study, we investigated metformin and its ability to activate mitophagy and alleviate inflammation in retinal pigment epithelium (RPE) cells upon induced mitochondrial damage.Methods: Experiments were conducted using the ARPE‐19 cell line. The cells were treated with 15 mM metformin (Met) for 1 h before adding 10 μM mitochondrial complex 3 inhibitor Antimycin A (Aa) for additional 2–24 h. The levels of proinflammatory cytokines IL‐6 and IL‐8 were measured using the enzyme‐linked immunosorbent assay (ELISA). The levels of the autophagy substrate SQSTM1/p62 and the autophagy marker LC3 were studied using the Western blot method. To further analyse mitophagy, LC3 and TOM20 colocalization was detected using immunofluorescence. Mitochondrial ROS production was assessed using MitoSOX CMXRos staining.Results: The production of proinflammatory cytokines IL‐6 and IL‐8 were increased by Aa exposure. Conversely, Met treatment significantly reduced the levels of IL‐6 and IL‐8. The autophagy substrate SQSTM1/p62 was accumulated in the cells after Aa treatment implying a blockage in the autophagic flux. Met treatment induced the clearance of SQSTM1/p62 and LC3 I and II at 6‐h time point. At 24‐h time point, Met treatment increased the amount of LC3 puncta/cell and colocalization of LC3 and TOM20 suggesting enhanced mitophagy in cells suffering mitochondrial damage induced by Aa. Aa treatment led to increased production of mitochondrial ROS which was decreased by Met treatment.Conclusions: Metformin has anti‐inflammatory and antioxidant properties in human RPE cells upon antimycin A exposure. Studies on autophagy markers suggest enhanced activation of autophagy, and mitophagy, upon metformin exposure, which could explain the detected positive effects on inflammation and oxidative stress.

Differences in the expression of the phosphatase PTP-1B in patients with localized prostate cancer with and without adverse pathological features.

Patients with adverse pathological features (APF) at radical prostatectomy (RP) for prostate cancer (PC) are candidates for adjuvant treatment. Clinicians lack reliable markers to predict these APF preoperatively. Protein tyrosine phosphatase 1B (PTP-1B) is involved in migration and invasion of PC, and its expression could predict presence of APF. Our aim was to compare PTP-1B expression in patients with and without APF, and to explore PTP-1B expression as an independent prognostic factor. Tissue microarrays (TMAs) were constructed using RP archival specimens for immunohistochemical staining of PTP-1B; expression was reported with a standardized score (0-9). We compared median PTP-1B score between cases with and without APF. We constructed two logistic regression models, one to identify the independence of PTP-1B score from biologically associated variables (metformin use and type 2 diabetes mellitus [T2DM]) and the second to seek independence of known risk factors (Gleason score and prostate specific antigen [PSA]). A total of 73 specimens were suitable for TMA construction. Forty-four (60%) patients had APF. The median PTP-1B score was higher in those with APF: 8 (5-9) vs 5 (3-8) (p=0.026). In the logistic regression model including T2DM and metformin use, the PTP-1B score maintained statistical significance (OR 1.21, 95% CI 1.01-1.45, p=0.037). In the model including PSA and Gleason score; the PTP-1B score showed no independence (OR 1.68, 95% CI 0.97-1.41, p=0.11). The area under the curve to predict APF for the PTP-1B score was 0.65 (95% CI 0.52-0.78, p=0.03), for PSA+Gleason 0.71 (95% CI 0.59-0.82, p=0.03), and for PSA+Gleason+PTP-1B score 0.73 (95% CI 0.61-0.84, p=0.001). Patients with APF after RP have a higher expression of PTP-1B than those without APF, even after adjusting for T2DM and metformin exposure. PTP-1B has a good accuracy for predicting APF but does not add to known prognostic factors.

Prevalence of vitamin B12 deficiency in patients treated with metformin

Background/Aim: Metformin has been associated with vitamin B 12 (cobalamin) deficiency, pushing scientific societies such as the American Diabetes Association and the European Association for the Study of Diabetes to emphasise the need for screening B 12 levels, without specific metformin doses or exposure durations triggering this screening. Robust data regarding the prevalence of B 12 deficiency in metformin-treated patients in Portugal are currently lacking. Aim of this study was to identify the prevalence of B 12 deficiency in a sample of diabetic patients taking metformin. Secondary objectives were determining the minimum dose and minimum and median time exposure time leading to this deficiency and identifying the average duration of metformin use in the patients with this deficiency. Methods: Descriptive and cross-sectional observational study was performed on a sample of 79 users from a population of 714 diabetic patients on metformin. Inclusion criteria comprised individuals aged 18 or older, receiving metformin for at least 1 month and voluntarily participating in the study. Exclusion criteria included a history of gastrectomy or B 12 supplementation. Results: A prevalence of 25.3 % of vitamin B 12 deficiency was identified in the study sample. Minimum doses of 500 mg of metformin per day and a minimum exposure period of 1 year were associated with B 12 deficiency. An average exposure time of 5.33 years was identified. Conclusion: These results align with the prevalence described in the few international studies and should alert physicians to potential clinical manifestations of this deficiency, such as anaemia and neurological symptoms like neuropathy.