Evidence for a role of metformin in preventing olfactory dysfunction among older adults

BACKGROUND

Olfactory dysfunction (OD) is increasingly recognized as a hallmark of unhealthy aging and is intimately associated with mortality, but therapies remain elusive. Recognizing the increased prevalence of OD in individuals with diabetes, and the potential anti-aging effects of metformin, we studied the association of metformin use with OD.

METHODS

Cross-temporal study of participants from Waves 2 (2010-11) and 3 (2015-16) of the National Social Life, Health, and Aging Project (NSHAP), a nationally representative cohort study of community-dwelling older adults. We included participants with diabetes who had complete data on olfaction and relevant covariates at Wave 2 and were not lost to follow-up at Wave 3. Olfactory identification (OI), the ability to identify the odorant, and olfactory sensitivity (OS), the ability to detect the presence of an odorant, were tested. Weighted multivariable logistic regression was used to study the association between metformin use at Wave 2 (baseline) and odds of having impaired OI/OS at Wave 3, adjusted for age, sex, race/ethnicity, education, smoking, BMI, HbA1c, years since diabetes diagnosis, and insulin use.

RESULTS

Among 228 participants with diabetes (mean age=70 years, 53% female, 21% Black), 112 (49%) used metformin at baseline. Relative to nonusers, users had 58% lower odds of impaired OI and 67% lower odds of impaired OS at Wave 3. Among participants with normal baseline OS (N=62), users had 97% lower odds of impaired OS at Wave 3.

CONCLUSIONS

Metformin use is associated with lower odds of OD among individuals with diabetes, suggesting a potential protective effect on olfaction. Future work including a larger sample and additional information on metformin use is needed to establish whether these findings are independent of diabetic control.

Safety vs price in the generic drug market: metformin

OBJECTIVES

Generic medications represent 90% of prescriptions in the US market and provide a tremendous financial benefit for patients. Recently, multiple generic drugs have been recalled due to the presence of carcinogens, predominantly N-nitrosodimethylamine (NDMA), including an extensive recall of extended-release (ER) metformin products in 2020.

STUDY DESIGN

Primary pharmaceutical quality testing and database analysis.

METHODS

We tested marketed metformin immediate-release (IR) and ER tablets from a wide sample of generic manufacturers for the presence of carcinogenic impurities NDMA and N,N-dimethylformamide (DMF). We examined the association of level of impurity with drug price and the impact of the 2020 FDA recalls on unit price and prescription fill rate.

RESULTS

Postrecall NDMA levels were significantly lower in metformin ER samples (standardized mean difference = -2.0; P = .01); however, we found continued presence of carcinogens above the FDA threshold in 2 of 30 IR samples (6.67%). Overall, the presence of contaminant levels was not significantly associated with price for either IR (NDMA: R2 = 0.142; P = .981; DMF: R2 = 0.382; P = .436) or ER (NDMA: R2 = 0.124; P = .142; DMF: R2 = 0.199; P = .073) samples. Despite recalls, metformin ER prescription fills increased by 8.9% while unit price decreased by 19.61% (P < .05).

CONCLUSIONS

Recalls of metformin ER medications were effective in lowering NDMA levels below the FDA threshold; however, some samples of generic metformin still contained carcinogens even after FDA-announced recalls. The absence of any correlation with price indicates that potentially safer products are available on the market for the same price as poorer-quality products.

Emotional Distress Predicts Reduced Type 2 Diabetes Treatment Adherence in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

We examined longitudinal associations between emotional distress (specifically, depressive symptoms and diabetes distress) and medication adherence in Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE), a large randomized controlled trial comparing four glucose-lowering medications added to metformin in adults with relatively recent-onset type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

The Emotional Distress Substudy assessed medication adherence, depressive symptoms, and diabetes distress in 1,739 GRADE participants via self-completed questionnaires administered biannually up to 3 years. We examined baseline depressive symptoms and diabetes distress as predictors of medication adherence over 36 months. Bidirectional visit-to-visit relationships were also examined. Treatment satisfaction, beliefs about medication, diabetes care self-efficacy, and perceived control over diabetes were evaluated as mediators of longitudinal associations.

RESULTS

At baseline, mean ± SD age of participants (56% of whom were White, 17% Hispanic/Latino, 18% Black, and 66% male) was 58.0 ± 10.2 years, diabetes duration 4.2 ± 2.8 years, HbA1c 7.5% ± 0.5%, and medication adherence 89.9% ± 11.1%. Higher baseline depressive symptoms and diabetes distress were independently associated with lower adherence over 36 months (P < 0.001). Higher depressive symptoms and diabetes distress at one visit predicted lower adherence at the subsequent 6-month visit (P < 0.0001) but not vice versa. Treatment assignment did not moderate relationships. Patient-reported concerns about diabetes medications mediated the largest percentage (11.9%-15.5%) of the longitudinal link between emotional distress and adherence.

CONCLUSIONS

Depressive symptoms and diabetes distress both predict lower adherence to glucose-lowering medications over time among adults with T2DM. Addressing emotional distress and concerns about anticipated negative effects of taking these treatments may be important to support diabetes treatment adherence.

Effectiveness of metformin for the reversal of cold-ischemia-induced damage in hepatosteatosis

BACKGROUND

Primary dysfunction and rejection are more common in donor liver tissues with steatosis. AMP-activated protein kinase (AMPK) assumes organ-protective functions during ischemia. Metformin was used for the activation of AMPK in hepatocytes. The aim of this study is to investigate the effectiveness of metformin administration for the reversal of cold-ischemia-induced damage in hepatosteatosis.

MATERIAL AND METHODS

Seven-week-old C7BL56 male-mice (n = 109) were separated into four groups depending on diet type and metformin use. A specific diet model was followed for 10 weeks to induce hepatosteatosis. A group of the animals was administered with metformin for the last four weeks via oral gavage. After resection, the liver tissues were perfused and kept for 0-6-12-24 h in the UW solution. Histopathological examinations were performed, and Western blot was utilized to analyze p-AMPK and AMPK expression levels.

RESULTS

Hepatosteatosis decreased significantly with metformin. The steatotic liver group had more prominent pericentral inflammation, necrosis as well as showing a decreased and more delayed AMPK response than the non-fat group. All these alterations could be corrected using metformin.

CONCLUSION

Metformin can increase the resistance of livers with hepatosteatosis to cold-ischemia-induced damage, which in turn may pave the way for successful transplantation of fatty living-donor livers.

Differential Effects of Type 2 Diabetes Treatment Regimens on Diabetes Distress and Depressive Symptoms in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

We evaluated whether adding basal insulin to metformin in adults with early type 2 diabetes mellitus (T2DM) would increase emotional distress relative to other treatments.

RESEARCH DESIGN AND METHODS

The Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) of adults with T2DM of <10 years' duration, HbA1c 6.8-8.5%, and taking metformin monotherapy randomly assigned participants to add insulin glargine U-100, sulfonylurea glimepiride, the glucagon-like peptide-1 receptor agonist liraglutide, or the dipeptidyl peptidase 4 inhibitor sitagliptin. The Emotional Distress Substudy enrolled 1,739 GRADE participants (mean [SD] age 58.0 [10.2] years, 32% female, 56% non-Hispanic White, 18% non-Hispanic Black, 17% Hispanic) and assessed diabetes distress and depressive symptoms every 6 months. Analyses examined differences at 1 year and over the 3-year follow-up.

RESULTS

Across treatments, diabetes distress (-0.24, P < 0.0001) and depressive symptoms (-0.67, P < 0.0001) decreased over 1 year. Diabetes distress was lower at 1 year for the glargine group than for the other groups combined (-0.10, P = 0.002). Diabetes distress was also lower for liraglutide than for glimepiride or sitagliptin (-0.10, P = 0.008). Over the 3-year follow-up, there were no significant group differences in total diabetes distress; interpersonal diabetes distress remained lower for those assigned to liraglutide. No significant differences were observed for depressive symptoms.

CONCLUSIONS

Contrary to expectations, this randomized trial found no evidence for a deleterious effect of basal insulin on emotional distress. Glargine lowered diabetes distress modestly at 1 year rather than increasing it. Liraglutide also reduced diabetes distress at 1 year. Results can inform treatment decisions for adults with early T2DM.

Metformin Overcomes the Consequences of NKX3.1 Loss to Suppress Prostate Cancer Progression

BACKGROUND

The antidiabetic drug metformin has known anticancer effects related to its antioxidant activity; however, its clinical benefit for prostate cancer (PCa) has thus far been inconclusive. Here, we investigate whether the efficacy of metformin in PCa is related to the expression status of NKX3.1, a prostate-specific homeobox gene that functions in mitochondria to protect the prostate from aberrant oxidative stress.

OBJECTIVE

To investigate the relationship of NKX3.1 expression and metformin efficacy in PCa.

DESIGN, SETTING, AND PARTICIPANTS

Functional studies were performed in vivo and in vitro in genetically engineered mouse models and human LNCaP cells, and organotypic cultures having normal or reduced/absent levels of NKX3.1. Correlative studies were performed using two independent retrospective tissue microarray cohorts of radical prostatectomies and a retrospective cohort of prostate biopsies from patients on active surveillance.

INTERVENTION

Metformin was administered before or after the induction of oxidative stress by treatment with paraquat.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Functional endpoints included analyses of histopathology, tumorigenicity, and mitochondrial function. Correlative endpoints include Kaplan-Meier curves and Cox proportional hazard regression models.

RESULTS AND LIMITATIONS

Metformin reversed the adverse consequences of NKX3.1 deficiency following oxidative stress in vivo and in vitro, as evident by reduced tumorigenicity and restored mitochondrial function. Patients with low NKX3.1 expression showed a significant clinical benefit from taking metformin.

CONCLUSIONS

Metformin can overcome the adverse consequences of NKX3.1 loss for PCa progression by protecting against oxidative stress and promoting normal mitochondrial function. These functional activities and clinical correlates were observed only with low NKX3.1 expression. Thus, the clinical benefit of metformin in PCa may depend on the status of NKX3.1 expression.

PATIENT SUMMARY

Prostate cancer patients with low NKX3.1 are likely to benefit most from metformin treatment to delay disease progression in a precision interception paradigm.

Metformin and feeding increase levels of the appetite-suppressing metabolite Lac-Phe in humans

Metformin, a widely used first-line treatment for type 2 diabetes (T2D), is known to reduce blood glucose levels and suppress appetite. Here we report a significant elevation of the appetite-suppressing metabolite N-lactoyl phenylalanine (Lac-Phe) in the blood of individuals treated with metformin across seven observational and interventional studies. Furthermore, Lac-Phe levels were found to rise in response to acute metformin administration and post-prandially in patients with T2D or in metabolically healthy volunteers.

Impact of Insulin Sensitivity and β-Cell Function Over Time on Glycemic Outcomes in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE): Differential Treatment Effects of Dual Therapy

OBJECTIVE

To compare the effects of insulin sensitivity and β-cell function over time on HbA1c and durability of glycemic control in response to dual therapy.

RESEARCH DESIGN AND METHODS

GRADE participants were randomized to glimepiride (n = 1,254), liraglutide (n = 1,262), or sitagliptin (n = 1,268) added to baseline metformin and followed for mean ± SD 5.0 ± 1.3 years, with HbA1c assessed quarterly and oral glucose tolerance tests at baseline, 1, 3, and 5 years. We related time-varying insulin sensitivity (HOMA 2 of insulin sensitivity [HOMA2-%S]) and early (0-30 min) and total (0-120 min) C-peptide (CP) responses to changes in HbA1c and glycemic failure (primary outcome HbA1c ≥7% [53 mmol/mol] and secondary outcome HbA1c >7.5% [58 mmol/mol]) and examined differential treatment responses.

RESULTS

Higher HOMA2-%S was associated with greater initial HbA1c lowering (3 months) but not subsequent HbA1c rise. Greater CP responses were associated with a greater initial treatment response and slower subsequent HbA1c rise. Higher HOMA2-%S and CP responses were each associated with lower risk of primary and secondary outcomes. These associations differed by treatment. In the sitagliptin group, HOMA2-%S and CP responses had greater impact on initial HbA1c reduction (test of heterogeneity, P = 0.009 HOMA2-%S, P = 0.018 early CP, P = 0.001 total CP) and risk of primary outcome (P = 0.005 HOMA2-%S, P = 0.11 early CP, P = 0.025 total CP) but lesser impact on HbA1c rise (P = 0.175 HOMA2-%S, P = 0.006 early CP, P < 0.001 total CP) in comparisons with the glimepiride and liraglutide groups. There were no differential treatment effects on secondary outcome.

CONCLUSIONS

Insulin sensitivity and β-cell function affected treatment outcomes irrespective of drug assignment, with greater impact in the sitagliptin group on initial (short-term) HbA1c response in comparison with the glimepiride and liraglutide groups.

Metformin role in Parkinson's disease: a double-sword effect

Parkinson's disease (PD) is a common neurodegenerative disease developed due to the degeneration of dopaminergic neurons in the substantia nigra. There is no single effective treatment in the management of PD. Therefore, repurposing effective and approved drugs like metformin could be an effective strategy for managing PD. However, the mechanistic role of metformin in PD neuropathology was not fully elucidated. Metformin is an insulin-sensitizing agent used as a first-line therapy in the management of type 2 diabetes mellitus (T2DM) and has the ability to reduce insulin resistance (IR). Metformin may have a beneficial effect on PD neuropathology. The neuroprotective effect of metformin is mainly mediated by activating adenosine monophosphate protein kinase (AMPK), which reduces mitochondrial dysfunction, oxidative stress, and α-synuclein aggregation. As well, metformin mitigates brain IR a hallmark of PD and other neurodegenerative diseases. However, metformin may harm PD neuropathology by inducing hyperhomocysteinemia and deficiency of folate and B12. Therefore, this review aimed to find the potential role of metformin regarding its protective and detrimental effects on the pathogenesis of PD. The mechanistic role of metformin in PD neuropathology was not fully elucidated. Most studies regarding metformin and its effectiveness in PD neuropathology were observed in preclinical studies, which are not fully translated into clinical settings. In addition, metformin effect on PD neuropathology was previously clarified in T2DM, potentially linked to an increasing PD risk. These limitations hinder the conclusion concerning the therapeutic efficacy of metformin and its beneficial and detrimental role in PD. Therefore, as metformin does not cause hypoglycemia and is a safe drug, it should be evaluated in non-diabetic patients concerning PD risk.

Prusogliptin (DBPR108) monotherapy in treatment-naïve patients with type 2 diabetes: A randomized, double-blind, active and placebo-controlled, phase 3 study

AIM

This study aimed to assess the efficacy and safety of prusogliptin (DBPR108), a novel and highly selective dipeptidyl peptidase-4 inhibitor, in individuals with type 2 diabetes who had not been using glucose-lowering agents regularly for the 8 weeks before the screening period.

MATERIALS AND METHODS

In this multicentre, randomized, double-blind, phase 3 study, adult patients with type 2 diabetes were randomly assigned to receive either DBPR108 100 mg, sitagliptin 100 mg, or placebo once daily during the initial 24-week double-blind treatment period, followed by a 28-week open-label extension period during which all patients received DBPR108 100 mg once daily. The primary endpoint was the mean change in glycated haemoglobin (HbA1c) levels from baseline to week 24.

RESULTS

In total, 766 patients were enrolled and received DBPR108 100 mg (n = 462), sitagliptin 100 mg (n = 152), or placebo (n = 152). The mean age of all patients was 54.3 ± 10.5 years, with 58% being men. The median duration of type 2 diabetes was 0.38 (0.02, 2.65) years, and the mean HbA1c (SD) at baseline was 7.94% (0.62), 7.88% (0.61) and 7.83% (0.59) for DBPR108, sitagliptin and placebo groups, respectively. At week 24, the least square mean (SE) changes from baseline in HbA1c were -0.63% (0.04%) for DBPR108, -0.60% (0.07%) for sitagliptin and -0.02% (0.07%) for placebo. The mean treatment difference between DBPR108 and placebo was -0.61% (95% CI -0.77% to -0.44%), and between DBPR108 and sitagliptin was -0.03% (95% CI -0.19% to 0.13%). These results indicate that DBPR108 was superior to placebo and non-inferior to sitagliptin. DBPR108 also significantly reduced fasting and postprandial plasma glucose levels and had little effect on body weight. The mean (SD) changes in HbA1c from baseline to week 52 were -0.50% (0.97%) for the DBPR108 group, -0.46% (0.96%) for the sitagliptin group and -0.41% (0.95%) for the placebo group. The incidence of adverse events was comparable across all three groups.

CONCLUSIONS

DBPR108 showed superiority to placebo and non-inferiority to sitagliptin in terms of glycaemic control over the initial 24 weeks in treatment-naïve patients with type 2 diabetes. Furthermore, its efficacy was sustained for up to 52 weeks.

Impact of Glucose-Lowering Medications on Health-Related Quality of Life in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

Diabetes is associated with reduced health-related quality of life (HRQoL). Information on the relationship between HRQoL and glucose-lowering medications in recently diagnosed type 2 diabetes (T2D) is limited. We assessed changes in HRQoL in participants with T2D receiving metformin plus one of four glucose-lowering medications in Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE).

RESEARCH DESIGN AND METHODS

A total of 5,047 participants, baseline mean age 57 years, with <10 years T2D duration and glycated hemoglobin level 6.8-8.5% and taking metformin monotherapy, were randomly assigned to glargine, glimepiride, liraglutide, or sitagliptin. HRQoL was evaluated at baseline for 4,885 participants, and at years 1, 2, and 3, with use of the self-administered version of the Quality of Well-being Scale (QWB-SA) and SF-36 physical (PCS) and mental (MCS) component summary scales. Linear models were used to analyze changes in HRQoL over time in intention-to-treat analyses.

RESULTS

None of the medications worsened HRQoL. There were no differences in QWB-SA or MCS by treatment group at any time point. PCS scores improved with liraglutide versus other groups at year 1 only. Greater weight loss during year 1 explained half the improvement in PCS scores with liraglutide versus glargine and glimepiride. Liraglutide participants in the upper tertile of baseline BMI showed the greatest improvement in PCS scores at year 1.

CONCLUSIONS

Adding liraglutide to metformin in participants within 10 years of T2D diagnosis showed improvement in the SF-36 PCS in comparisons with the other medications at 1 year, which was no longer significant at years 2 and 3. Improvement was related to weight loss and baseline BMI.

The Use of Rescue Insulin in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

To describe rescue insulin use and associated factors in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE).

RESEARCH DESIGN AND METHODS

GRADE participants (type 2 diabetes duration <10 years, baseline A1C 6.8%-8.5% on metformin monotherapy, N = 5,047) were randomly assigned to insulin glargine U-100, glimepiride, liraglutide, or sitagliptin and followed quarterly for a mean of 5 years. Rescue insulin (glargine or aspart) was to be started within 6 weeks of A1C >7.5%, confirmed. Reasons for delaying rescue insulin were reported by staff-completed survey.

RESULTS

Nearly one-half of GRADE participants (N = 2,387 [47.3%]) met the threshold for rescue insulin. Among participants assigned to glimepiride, liraglutide, or sitagliptin, rescue glargine was added by 69% (39% within 6 weeks). Rescue aspart was added by 44% of glargine-assigned participants (19% within 6 weeks) and by 30% of non-glargine-assigned participants (14% within 6 weeks). Higher A1C values were associated with adding rescue insulin. Intention to change health behaviors (diet/lifestyle, adherence to current treatment) and not wanting to take insulin were among the most common reasons reported for not adding rescue insulin within 6 weeks.

CONCLUSIONS

Proportionately, rescue glargine, when required, was more often used than rescue aspart, and higher A1C values were associated with greater rescue insulin use. Wanting to use noninsulin strategies to improve glycemia was commonly reported, although multiple factors likely contributed to not using rescue insulin. These findings highlight the persistent challenge of intensifying type 2 diabetes treatment with insulin, even in a clinical trial.

The effect of SGLT2i on the GH/IGF1 axis in newly diagnosed male T2D patients - a prospective, randomized case-control study

PURPOSE

To investigate the effect of SGLT2i on the GH/IGF1 axis in male patients with newly diagnosed type 2 diabetes (T2D).

METHODS

Sixty male patients with newly diagnosed T2D were recruited, and randomly assigned to Metformin+SGLT2i group or Metformin group after baseline assessment. All patients received standard lifestyle interventions, and blood indices were obtained before and after 12 weeks of treatment.

RESULTS

After 12 weeks of treatment with Metformin+SGLT2i, there were noteworthy improvements in patients' FPG (Fasting plasma glucose), HBA1c, HOMA-IR, HOMA-β, TyG (Triglyceride-glucose) index and UACR (P < 0.05). Both IGF1 (P = 0.01) and the IGF1/IGFBP3 ratio (P < 0.01) considerably increased, while GH and IGFBP3 did not show significant changes. When comparing Metformin+SGLT2i group to Metformin group, SGLT2i significantly improved HOMA-IR [P = 0.04], and elevated IGF1/IGFBP3 ratio [P = 0.04], SGLT2i showed a tendency of increasing IGF1 (P = 0.10), but this was not statistically meaningful. There was no effect on GH and IGFBP3. Correlation analysis showed that blood IGF1 was negatively correlated with FPG, HBA1c, HOMA-IR, TyG index and positively correlated with IGFBP3. Regression analysis indicated that FPG and testosterone had a negative effect on blood IGF1 level, while HOMA-IR had no obvious effect.

CONCLUSION

In male patients with newly diagnosed T2D, SGLT2i can increase IGF1/IGFBP3 ratio, alleviate insulin resistance, but has no significant effect on GH and IGF1 levels. Additionally, our study showed that Metformin+SGLT2i treatment resulted in an increase in blood IGF1 levels and improved insulin resistance, suggesting a potentially beneficial role of IGF1 in newly diagnosed T2D.

Metformin suppresses NFE2L1 pathway activation to inhibit gap junction beta protein expression in NSCLC

OBJECTIVE

Non-small-cell lung cancer (NSCLC) is a deadly form of cancer that exhibits extensive intercellular communication which contributed to chemoradiotherapy resistance. Recent evidence suggests that arrange of key proteins are involved in lung cancer progression, including gap junction proteins (GJPs).

METHODS AND RESULTS

In this study, we examined the expression patterns of GJPs in NSCLC, uncovering that both gap junction protein, beta 2 (GJB2) and gap junction protein, beta 2 (GJB3) are increased in LUAD and LUSC. We observed a correlation between the upregulation of GJB2, GJB3 in clinical samples and a worse prognosis in patients with NSCLC. By examining the mechanics, we additionally discovered that nuclear factor erythroid-2-related factor 1 (NFE2L1) had the capability to enhance the expression of connexin26 and connexin 31 in the NSCLC cell line A549. In addition, the use of metformin was discovered to cause significant downregulation of gap junction protein, betas (GJBs) by limiting the presence of NFE2L1 in the cytoplasm.

CONCLUSION

This emphasizes the potential of targeting GJBs as a viable treatment approach for NSCLC patients receiving metformin.

Metformin use is associated with reduced mortality risk in diabetic patients with Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) and type-2 diabetes (T2D) arguably share pathophysiologic mechanisms, resulting in a more severe phenotype and progression and diabetes is currently considered a risk factor of PD. Besides, research suggests antidiabetic therapies as potential disease-modifying strategies. The main aim was to assess the impact of a metformin-inclusive antidiabetic treatment on patient all-cause mortality.

METHODS

A nested case-control prospective study including newly diagnosed PD patients reporting the onset of T2D within ±2 years from the onset of PD (n = 159) and matched (1:5; gender, year of PD onset and age at PD onset) non-diabetic cases (n = 795) followed until death or censoring. Patients on a metformin-inclusive treatment regimen were compared to those receiving other oral anti-diabetics (OADs).

RESULTS

Among patients with T2D, 123 were treated with a drug regimen containing metformin (alone [65.0%] or in combination with other drugs [35.0%]) and 36 were prescribed other OADs. During a median PD duration of 96 months [IQR, 60-144], 171 patients died. Diabetes was not associated with reduced survival: fully-adjusted HR = 1.19 [95%CI, 0.81-1.76] (P = 0.37). After stratifying for T2D treatment, a metformin-inclusive regimen was not associated with increased risk of death (HR = 1.06 [95%CI, 0.61-1.84]; P = 0.83), while patients receiving other OADs had reduced survival (HR = 1.83 [95%CI, 1.01-3.32]; P = 0.034).

CONCLUSIONS

Metformin use was not associated with increased risk of death in diabetic patients with PD reporting concomitant onset of the two diseases. Metformin appears to be a promising disease-modifying therapy given also the preclinical background, low cost and satisfactory safety and tolerability. Further studies are warranted to investigate its impact on disease progression.

Effect of metformin on anti-mullerian hormone levels in women with polycystic ovarian syndrome: a systematic review and meta-regression analysis of randomized controlled trials with

BACKGROUND

Several interventional studies have evaluated the potential anti-Mullerian hormone (AMH)-reduction effect of metformin. However, the results are still contradictory. In order to obtain a better viewpoint from them, this study aimed to comprehensively investigate the effects of metformin on AMH in the women with with polycystic ovarian syndrome (PCOS).

METHODS

Scopus, PubMed/Medline, Web of Science, Cochrane, and Embase databases were searched using standard keywords to identify all controlled trials investigating the AMH levels following metformin administration. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model analysis for the best estimation of outcomes.

RESULTS

Sixteen studies with 484 participants' were included in this article. The pooled findings showed that AMH levels in the single arm clinical trials were significantly reduced (pooled WMD of -3.06 ng/ml; 95% confidence interval [CI] -4.03 to -2.10; P < 0.001) after use of metformin. Furthermore, compared to the control group, in randomized clinical trials, a reduced significant effect on AMH levels was observed following use of metformin (pooled WMD of -3.47 ng/ml; 95% CI -7.14 to -0.19; P = 0.047). Furthermore, higher reduction in the AMH levels with a metformin dosage ≤ 1500 mg/day and duration of treatment ≤ 12 weeks when compared to higher dosages and duration of intervention, observed in this meta-analysis.

CONCLUSIONS

In conclusion, results this meta-analysis of clinical trials confirms the beneficial effect of the treatment with metformin in the reduction of the AMH levels in women.

Predictive factors and the management of hyperglycemia in patients with acromegaly and Cushing's disease receiving pasireotide treatment: post hoc analyses from the SOM230B2219 study

Introduction

Pasireotide, a somatostatin receptor ligand, is approved for treating acromegaly and Cushing's disease (CD). Hyperglycemia during treatment can occur because of the drug's mechanism of action, although treatment discontinuation is rarely required. The prospective, randomized, Phase IV SOM230B2219 (NCT02060383) trial was designed to assess optimal management of pasireotide-associated hyperglycemia. Here, we investigated predictive factors for requiring antihyperglycemic medication during pasireotide treatment.

Methods

Participants with acromegaly or CD initiated long-acting pasireotide 40 mg/28 days intramuscularly (acromegaly) or pasireotide 600 μg subcutaneously twice daily during pre-randomization (≤16 weeks). Those who did not need antihyperglycemic medication, were managed with metformin, or received insulin from baseline entered an observational arm ending at 16 weeks. Those who required additional/alternative antihyperglycemic medication to metformin were randomized to incretin-based therapy or insulin for an additional 16 weeks. Logistic-regression analyses evaluated quantitative and qualitative factors for requiring antihyperglycemic medication during pre-randomization.

Results

Of 190 participants with acromegaly and 59 with CD, 88 and 15, respectively, did not need antihyperglycemic medication; most were aged <40 years (acromegaly 62.5%, CD 86.7%), with baseline glycated hemoglobin (HbA1c) <6.5% (<48 mmol/mol; acromegaly 98.9%, CD 100%) and fasting plasma glucose (FPG) <100 mg/dL (<5.6 mmol/L; acromegaly 76.1%, CD 100%). By logistic regression, increasing baseline HbA1c (odds ratio [OR] 3.6; P=0.0162) and FPG (OR 1.0; P=0.0472) and history of diabetes/pre-diabetes (OR 3.0; P=0.0221) predicted receipt of antihyperglycemic medication in acromegaly participants; increasing baseline HbA1c (OR 12.6; P=0.0276) was also predictive in CD participants. Investigator-reported hyperglycemia-related adverse events were recorded in 47.9% and 54.2% of acromegaly and CD participants, respectively, mainly those with diabetes/pre-diabetes.

Conclusion

Increasing age, HbA1c, and FPG and pre-diabetes/diabetes were associated with increased likelihood of requiring antihyperglycemic medication during pasireotide treatment. These risk factors may be used to identify those who need more vigilant monitoring to optimize outcomes during pasireotide treatment.

Evaluating synergistic effects of metformin and simvastatin on ovarian cancer cells

BACKGROUND

Ovarian Cancer (OC) stands as the most lethal gynecological malignancy, presenting an urgent clinical challenge in the quest to improve response rates. One approach to address this challenge is through drug repurposing, exemplified by the investigation of metabolic-modulating drugs such as Metformin (MTF) and Simvastatin (SIM). This study aims to explore the molecular mechanisms contributing to the potential synergistic anti-cancer effects between MTF and SIM on ovarian cancer cells.

METHODS

We assessed the effects of the combination on the proliferation and viability of two cell lines OVCAR-3 and SKOV-3. IC50 concentrations of MTF and SIM were determined using a proliferation assay, followed by subtoxic concentrations to explore the potential synergistic effects on the viability of both cell lines. Transcriptomic analysis was conducted on OVCAR-3 treated cells, and the findings were validated by assessing the expression levels of differentially expressed genes (DEGs) through real-time PCR in both cell lines SK-OV-3 and OVCAR-3.

RESULTS

Cytotoxicity analysis guided the selection of treatment concentrations as such MTF 10 mM and SIM 5 μM. The combined treatment of MTF and SIM demonstrated a synergistic inhibition of proliferation and viability in both cell lines. In OVCAR-3, exclusive identification of 507 DEGs was seen in the combination arm. Upregulation of FOXO3, RhoA, and TNFα, along with downregulation of PIK3R1, SKP2, and ATP6V1D levels, was observed in OVCAR-3 treated cells. Real-time PCR validation confirmed the consistency of expression levels for the mentioned DEGs.

CONCLUSION

Our data strongly supports the presence of synergy between MTF and SIM in OC cells. The combination's effect is associated with the dysregulation of genes in the key regulators AMPK and mTOR alongside other interconnected pathways.

Just a spoonful of metformin helps the medicine go down

Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor with a need for novel therapies. So far, monotherapies have failed to prolong survival for these patients, and combinatorial strategies have often shown severe, dose-limiting toxicities. In this issue of the JCI, Duchatel, Jackson, and colleagues address this challenge by introducing a drug combination that mitigates side effects and overcomes resistance. After identifying the PI3K/mTOR pathway as a therapeutic vulnerability, they treated DIPG-bearing mice with paxalisib and saw responses but also observed hyperglycemia as a severe side effect. Combining paxalisib with metformin mitigated this toxicity, but also upregulated protein kinase C (PKC) signaling. To tackle this mechanism of resistance, the authors added the PKC inhibitor enzastaurin to their drug combination and showed that this triple therapy led to improved survival. This approach paves the way for improved outcomes for patients with DIPG and other brain tumors.

BNC1 deficiency induces mitochondrial dysfunction-triggered spermatogonia apoptosis through the CREB/SIRT1/FOXO3 pathway: the therapeutic potential of nicotinamide riboside and metformin†

Male infertility is a global health problem that disturbs numerous couples worldwide. Basonuclin 1 (BNC1) is a transcription factor mainly expressed in proliferative keratinocytes and germ cells. A frameshift mutation of BNC1 was identified in a large Chinese primary ovarian insufficiency pedigree. The expression of BNC1 was significantly decreased in the testis biopsies of infertile patients with nonobstructive azoospermia. Previous studies have revealed that mice with BNC1 deficiency are generally subfertile and undergo gradual spermatogenic failure. We observed that apoptosis of spermatogonia is tightly related to spermatogenic failure in mice with a Bnc1 truncation mutation. Such impairment is related to mitochondrial dysfunction causing lower mitochondrial membrane potential and higher reactive oxygen species. We showed that downregulation of CREB/SIRT1/FOXO3 signaling participates in the above impairment. Administration of nicotinamide riboside or metformin reversed mitochondrial dysfunction and inhibited apoptosis in Bnc1-knockdown spermatogonia by stimulating CREB/SIRT1/FOXO3 signaling. Dietary supplementation with nicotinamide riboside or metformin in mutated mice increased SIRT1 signaling, improved the architecture of spermatogenic tubules, inhibited apoptosis of the testis, and improved the fertility of mice with a Bnc1 truncation mutation. Our data establish that oral nicotinamide riboside or metformin can be useful for the treatment of spermatogenic failure induced by Bnc1 mutation.

Acupotomy combined with metformin hydrochloride tablet for type 2 diabetes mellitus and its effect on serum inflammatory factors

OBJECTIVES

To observe the clinical efficacy of acupotomy combined with metformin hydrochloride tablet for type 2 diabetes mellitus (T2DM) and its effect on serum levels of inflammatory factors.

METHODS

A total of 68 patients with T2DM were randomized into an acupotomy group (34 cases, 2 cases dropped out) and a western medication group (34 cases, 2 cases dropped out). Metformin hydrochloride tablet was given orally in the western medication group, 0.5-1 g each time, twice a day, for continuous 8 weeks. On the basis of the treatment in the western medication group, acupotomy was applied at bilateral Geshu (BL 17), Weiwanxiashu (EX-B 3), Ganshu (BL 18) in the acupotomy group, once a week for continuous 8 weeks. Before and after treatment, in the two groups, blood glucose (fasting blood glucose [FBG], 2-hour plasma glucose [2 h PG] and glycosylated hemoglobin [HbA1c]), TCM syndrome score, blood lipids (total cholesterol [TC], triglyceride [TG], low density lipoprotein cholesterol [LDL-C] and high density lipoprotein cholesterol [HDL-C]), insulin (fasting insulin [FINS] and 2-hour insulin [2 h INS]), C-peptide indexes (fasting C-peptide [FC-P] and 2-hour C-peptide [2 h C-P]), dosage of metformin hydrochloride tablet and diabetes specific quality of life (DSQL) score were observed, the serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-17 were measured by ELISA.

RESULTS

After treatment, the FBG, 2 h PG, HbA1c, TCM syndrome scores, TC, TG, LDL-C, FINS, 2 h INS, FC-P, 2 h C-P, DSQL scores as well as the serum levels of TNF-α, IL-6, IL-17 were decreased compared with those before treatment (P<0.01), HDL-C was increased compared with that before treatment (P<0.01) in the two groups; the dosage of metformin hydrochloride tablet was decreased compared with that before treatment in the acupotomy group (P<0.01). After treatment, in the acupotomy group, the FBG, HbA1c, TCM syndrome score, TC, TG, LDL-C, FINS, 2 h INS, FC-P, 2 h C-P, dosage of metformin hydrochloride tablet, DSQL score as well as the serum level of TNF-α were lower than those in the western medication group (P<0.05).

CONCLUSIONS

Acupotomy combined with metformin hydrochloride tablet can improve the blood glucose, clinical symptoms and quality of life in patients with T2DM, its mechanism may be related to the regulation of inflammatory reaction.

[The long-term efficacy of metformin in megestrol acetate-based fertility-sparing treatment for patients with endometrial atypical hyperplasia and endometrioid endometrial cancer]

Objective: To assess the long-term efficacy of metformin in megestrol acetate (MA)-based fertility-sparing treatment for patients with endometrial atypical hyperplasia (EAH) and endometrioid endometrial cancer (EEC). Methods: The randomized controlled trail study was conducted from October 2013 to October 2017 in the Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China. Patients with EAH or EEC were firstly stratified according to pathology, and randomized to receive MA (160 mg orally, daily) plus metformin (500 mg orally, three times a day) or MA (160 mg orally, daily). Baseline data between two groups of patients were compared. Estimates of time to complete remission (CR) and recurrence-free survival (RFS) were calculated using the Kaplan-Meier method. Cox proportional-hazards regression model was used to estimate hazard ratios (HR) of related factors for recurrence-free survival. Quantitative data were represented by M (Q1, Q3). Results: A total of 150 patients were included, and 76 patients were allocated to receive MA plus metformin with the age of 32.5 (28.0, 36.0), while 74 patients received MA alone with the age of 32.0 (28.0, 36.0). By the end of follow-up period, 96.7% (n=145) of patients achieved complete remission, with a median follow-up time of 57.7 (26.7, 70.5) months. The median CR time for the MA plus metformin group and the MA alone group were 6.3 (3.5, 8.3) months and 6.8 (4.0, 9.3) months, respectively (P=0.193), with 2-year cumulative CR rate of 98.6% and 98.5%, respectively (P=0.879). The median time of RFS was 28.1 (12.5, 57.3) months for the MA plus metformin group and 33.3 (14.1, 62.5) months for the MA alone group (P=0.213), with a cumulative RFS rate of 61.9% and 65.8%, respectively (P=0.560). In the subgroup of non-obese (body mass index<28 kg/m2) patients with EAH, the median RFS times were 25.7 (7.6, 60.3) months and 47.3 (17.5, 64.8) months for the MA plus metformin group and the MA alone group, respectively (P=0.033), with a cumulative RFS rate of 57.5% and 80.6%, respectively (P=0.029). According to Cox proportional hazards regression analysis, undergoing assisted reproductive treatment (HR=2.358, 95%CI: 1.069-5.204, P=0.034) was identified as an independent risk factor for recurrence-free survival after complete remission of endometrial lesions. Conclusion: The long-term follow-up outcome indicates that there is no significant difference in CR time and RFS time between MA plus metformin therapy and MA alone therapy for patients with EAH or EEC.

Impact of metformin treatment on cobalamin status in persons with type 2 diabetes

Over the last decades, low vitamin B12 status has been reported in individuals with type 2 diabetes mellitus (T2DM). Metformin, the first-line therapy for lowering blood glucose, is the main driving factor behind this association. Although the relationship between vitamin B12 deficiency and metformin is well established, results of studies on the exact effect of the dose and duration of the therapy remain inconsistent. Additionally, a lack of consensus on the definition of vitamin B12 deficiency adds to the conflicting literature. The objectives of this review were to analyze and synthesize the findings on the effects of metformin dose and duration on vitamin B12 status in patients with T2DM and to outline the potential mechanisms underlying metformin's effect on vitamin B12. Metformin therapy has adversely affected serum vitamin B12 concentrations, a marker of vitamin B12 status. The metformin usage index (a composite score of metformin dose and duration) might serve as a potential risk assessment tool for vitamin B12 screening in patients with T2DM. Considering the health implications of suboptimal vitamin B12 status, vitamin B12 concentrations should be monitored periodically in high-risk patients, such as vegans who are receiving metformin therapy for T2DM. Additionally, it is prudent to implement lifestyle strategies concurrent with metformin therapy in individuals with T2DM, promoting an overall synergistic effect on their glycemic control.

Antidiabetic drug administration prevents bone mineral density loss: Evidence from a two-sample Mendelian randomization study

The aim of this study was to investigate the effect of common antidiabetic drugs on BMD by two-sample Mendelian randomization (MR). The single nucleotide polymorphisms that were strongly associated with insulin, metformin, rosiglitazone and gliclazide were extracted as instrumental variables (IVs) for MR analysis. The inverse variance weighted (IVW) method was used as the primary MR method to assess the causal effect of antidiabetic drugs on BMD, and other MR methods, including Weighted median, MR Egger and Weighted mode, were used for complementary analysis. Reliability and stability were assessed by the leave-one-out test. In the present work, IVW estimation of the causal effect of insulin on heel BMD demonstrated that there was a null effect of insulin on heel BMD (β = 0.765; se = 0.971; P = 0.430), while metformin treatment had a positive effect on heel BMD (β = 1.414; se = 0.460; P = 2.118*10-3). The causal relationship between rosiglitazone and heel BMD analysed by IVW suggested that there was a null effect of rosiglitazone on heel BMD (β = -0.526; se = 1.744; P = 0.763), but the causal effect of gliclazide on heel BMD evaluated by IVW demonstrated that there was a positive effect of gliclazide on heel BMD (β = 2.671; se = 1.340; P = 0.046). In summary, the present work showed that metformin and gliclazide have a role in reducing BMD loss in patients with diabetes and are recommended for BMD loss prevention in diabetes.

Metformin improves nonalcoholic fatty liver disease in db/db mice by inhibiting ferroptosis

Nonalcoholic fatty liver disease (NAFLD) is the primary complication of type 2 diabetes (T2DM)-related liver disease, lacking effective treatment options. Metformin (Met), a widely prescribed anti-hyperglycemic medication, has been found to protect against NAFLD. Ferroptosis, a newly discovered form of cell death, is associated with the development of NAFLD. Despite this association, the extent of Met's protective effects on NAFLD through the modulation of ferroptosis has yet to be thoroughly investigated. In the present study, the administration of erastin or Ras-selective lethal 3 (RSL3), both known ferroptosis inducers, resulted in elevated cell mortality and reduced cell viability in AML12 hepatocytes. Notably, Met treatment demonstrated the capacity to mitigate these effects. Furthermore, we observed increased ferroptosis levels in both AML12 hepatocytes treated with palmitate and oleate (PA/OA) and in the liver tissue of db/db mice. Met treatment demonstrated significant reductions in iron accumulation and lipid-related reactive oxygen species production, simultaneously elevating the glutathione/glutathione disulfide ratio in both PA/OA-treated AML12 hepatocytes and the liver tissue of db/db mice. Interestingly, the anti-ferroptosis effects of Met were significantly reversed with the administration of RSL3, both in vitro and in vivo. Mechanistically, Met treatment regulated the glutathione peroxidase 4/solute carrier family 7 member 11/acyl-CoA synthetase long-chain family member 4 axis to alleviate ferroptosis in NAFLD hepatocytes. Overall, our findings highlight the crucial role of ferroptosis in the development of T2DM-related NAFLD and underscore the potential of Met in modulating key factors associated with ferroptosis in the context of NAFLD.

The Association Between Metformin Use and New-Onset ICD Coding of Geographic Atrophy

Purpose

Metformin has been suggested to protect against the development of age-related macular degeneration (AMD) in multiple observational studies. However, the association between metformin and geographic atrophy (GA), a debilitating subtype of AMD, has not been analyzed.

Methods

We conducted a case-control study of patients ages 60 years and older with new-onset International Classification of Diseases (ICD) coding of GA in the Merative MarketScan Commercial and Medicare Databases between 2017 and 2021. Cases were matched with propensity scores estimated by age, region, hypertension, and Charlson Comorbidity Index to a control without GA of the same year. Exposure to metformin was assessed for cases and controls in the year prior to their index visit. Conditional multivariable logistic regression, adjusting for AMD risk factors, was used to calculate odd ratios and 95% confidence intervals (CIs). This study design and analysis were repeated in a sample of patients without diabetes.

Results

In the full sample, we identified 10,505 cases with GA and 10,502 matched controls without GA. In total, 1149 (10.9%) cases and 1277 (12.2%) controls were exposed to metformin, and in multivariable regression, metformin decreased the odds of new-onset ICD coding of GA by 12% (95% CI, 0.79-0.99). In the sample of patients without diabetes, we identified 7611 cases with GA and 7608 matched controls without GA. Twenty-nine (0.4%) cases and 63 (0.8%) controls were exposed to metformin, and in multivariable regression, metformin decreased the odds of new-onset ICD coding of GA by 47% (95% CI, 0.33-0.83).

Conclusions

Metformin may hold promise as a noninvasive, alternative agent to prevent the development of GA. This finding is notable due to shortcomings in recently approved therapeutics for GA and metformin's overall ease of use and few adverse effects. Additional studies are required to explore our findings further and motivate a clinical trial.

Metformin, Cognitive Function, and Changes in the Gut Microbiome

The decline in cognitive function and the prevalence of neurodegenerative disorders are among the most serious threats to health in old age. The prevalence of dementia has reached 50 million people worldwide and has become a major public health problem. The causes of age-related cognitive impairment are multiple, complex, and difficult to determine. However, type 2 diabetes (T2D) is linked to an enhanced risk of cognitive impairment and dementia. Human studies have shown that patients with T2D exhibit dysbiosis of the gut microbiota. This dysbiosis may contribute to the development of insulin resistance and increased plasma lipopolysaccharide concentrations. Metformin medication mimics some of the benefits of calorie restriction and physical activity, such as greater insulin sensitivity and decreased cholesterol levels, and hence may also have a positive impact on aging in humans. According to recent human investigations, metformin might partially restore gut dysbiosis related to T2D. Likewise, some studies showed that metformin reduced the risk of dementia and improved cognition, although not all studies are concordant. Therefore, this review focused on those human studies describing the effects of metformin on the gut microbiome (specifically the changes in taxonomy, function, and circulating metabolomics), the changes in cognitive function, and their possible bidirectional implications.

DPP-4 inhibition by linagliptin ameliorates age-related mild cognitive impairment by regulating microglia polarization in mice

Extensive preclinical evidence demonstrates a causative link between insulin signaling dysfunction and the pathogenesis of Alzheimer's disease (AD), and diabetic drugs may represent a promising approach to fighting AD. However, it remains to be determined which antidiabetic drugs are more effective in preventing cognitive impairment. Thus, the present study investigated the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin on cognitive impairment in middle-aged mice by comparing it with the effect of metformin. We found that DPP-4 activity increased in the hippocampus of middle-aged mice, and DPP-4 was mainly expressed by microglia rather than astrocytes and oligodendrocytes. DPP-4 directly regulated M1/M2 microglia polarization following LPS or IL-4 stimulation, while DPP-4 inhibitor, linagliptin, suppressed M1-polarized activation and induced M2-polarized activation. Both linagliptin and metformin enhanced cognitive ability, increased hippocampal synaptic plasticity and neurogenesis, and decreased age-related oxidative stress and inflammation by regulating microglia polarization in the hippocampus of middle-aged mice. The combination of linagliptin and metformin showed a maximum protective effect compared to the individual drugs alone. Loss of macrophage inflammatory protein-1α (MIP-1α), a DPP-4 substrate, abrogated the cognitive protection and anti-inflammation effects of linagliptin. Therefore, the current investigation exhibits a potential utility for DPP-4 inhibition in attenuating microglia-mediated inflammation and preventing mild cognitive impairment (MCI) in middle-aged mice, and the effect was partly mediated by MIP-1α.

Epicardial fat thickness in type 2 diabetes outpatient care

BACKGROUND AND AIM

Visceral fat is an independent predictor of the cardiovascular risk in subjects with type 2 diabetes (T2DM), but it is rarely assessed during an outpatient visit. Epicardial fat (EAT), the visceral fat of the heart, plays a role in coronary artery disease (CAD). EAT thickness can be clinically assessed with standard ultrasound. In this study we sought to evaluate the association of ambulatory ultrasound measured EAT thickness with CAD in asymptomatic well controlled T2DM subjects on metformin monotherapy during outpatient visits.

METHODS AND RESULTS

This was single center, pragmatic study in 142 T2DM patients. Each subject underwent baseline ultrasound EAT thickness measurement, anthropometric and biomarkers. The incidence of CAD was detected after 1 year. At baseline, HbA1c was 6.7 % and BMI 34.9 kg/m2, EAT thickness was 8.3 ± 2.3 in women and 9.4 ± 2.4 mm in men, higher than threshold values for high cardiovascular risk. In multivariate models, EAT was the only statistically significant correlate of CAD at 1-year f/u (p = 0.04).

CONCLUSIONS

Point of care ultrasound measured EAT thickness is a good correlate of CAD in well controlled and asymptomatic T2DM subjects on metformin monotherapy. EAT thickness predicted CAD better than traditional risk factors, such as BMI, HbA1c, age, blood pressure or duration of diabetes.

Insulin-sensitizing agents for infertility treatment in woman with polycystic ovary syndrome: a narrative review of current clinical practice

PURPOSE

Polycystic ovary syndrome (PCOS) is an endocrine, metabolic, and reproductive disorder which, according to the Rotterdam criteria, affects up to 24% of women of childbearing age. Although the prevalence of infertility in this subpopulation of women is high, the optimal treatment has not been fully established yet. Insulin resistance is considered to be an important mechanism involved in the development of PCOS; hence, the aim of this narrative review is to present an overview of the current pharmacological insulin-sensitizing treatment modalities for infertile women with PCOS.

METHODS

A MEDLINE and PubMed search for the years 1990-2023 was performed using a combination of keywords. Clinical trials with insulin sensitizers used for infertility treatment as well as analyses of systematic reviews and meta-analyses were evaluated. When deemed necessary, additional articles referenced in the retrieved papers were included in this narrative review.

RESULTS

Several insulin-sensitizing compounds and various therapeutical protocols are available for infertility treatment of women with PCOS. Metformin is the most common adjuvant medication to induce ovulation in infertile women with PCOS and is more frequently administered in combination with clomiphene citrate than on its own. Recently, inositol and glucagon-like peptide-1 (GLP-1) receptor agonists have emerged as possible options for infertility treatment in PCOS.

CONCLUSION

The future of medical treatment of PCOS women with infertility lies in a personalized pharmacological approach, which involves various compounds with different mechanisms of action that could modify ovarian function and endometrial receptivity, ultimately leading to better overall reproductive outcomes in these women.

Metformin inhibits cell proliferation and ACTH secretion in AtT20 cells via regulating the MAPK pathway

We investigated the impact of metformin on ACTH secretion and tumorigenesis in pituitary corticotroph tumors. The mouse pituitary tumor AtT20 cell line was treated with varying concentrations of metformin. Cell viability was assessed using the CCK-8 assay, ACTH secretion was measured using an ELISA kit, changes in the cell cycle were analyzed using flow cytometry, and the expression of related proteins was evaluated using western blotting. RNA sequencing was performed on metformin-treated cells. Additionally, an in vivo BALB/c nude xenograft tumor model was established in nude mice, and immunohistochemical staining was conducted for further verification. Following metformin treatment, cell proliferation was inhibited, ACTH secretion decreased, and G1/S phase arrest occurred. Analysis of differentially expressed genes revealed cancer-related pathways, including the MAPK pathway. Western blotting confirmed a decrease in phosphorylated ERK1/2 and phosphorylated JNK. Combining metformin with the ERK1/2 inhibitor Ulixertinib resulted in a stronger inhibitory effect on cell proliferation and POMC (Precursors of ACTH) expression. In vivo studies confirmed that metformin inhibited tumor growth and reduced ACTH secretion. In conclusion, metformin inhibits tumor progression and ACTH secretion, potentially through suppression of the MAPK pathway in AtT20 cell lines. These findings suggest metformin as a potential drug for the treatment of Cushing's disease.

Long-acting glucagon-like peptide 1 receptor agonists boost erectile function in men with type 2 diabetes mellitus complaining of erectile dysfunction: A retrospective cohort study

INTRODUCTION

The pharmacological management of erectile dysfunction (ED) in type 2 diabetes (T2D) is challenging as ED has a multifactorial etiology. The therapeutic potential of certain antihyperglycemic medications, such as glucagon-like peptide 1 receptor agonists (GLP-1RAs), has yet to be entirely studied in this setting.

MATERIAL AND METHODS

A retrospective cohort study was conducted on 108 outpatients (median age 60 [56, 65] years) with T2D complaining of ED. Data were extracted from a database referring to patients with a 1-year follow-up on stable treatment with metformin alone (n = 45) and GLP-1RAs as an add-on to metformin (n = 63). Erectile function was assessed by the 5-item International Index of Erectile Function (IIEF5) at baseline and after 1 year of stable treatment . Values were compared between baseline (T0) and after 12 months of treatment (T12).

RESULTS

ED was confirmed in all at baseline, with an IIEF5 score range between 13 and 19 points. After 12 months of treatment, glucose management was better in patients treated with GLP-1RAs plus metformin (HbA1c T0: 8.3 ± 0.2 vs. HbA1c T12: 7% ± 0.3%, p < 0.0001) than in those on metformin alone (HbA1c T0: 7 ± 0.5 vs. HbA1c T12: 7.3 ± 0.4, p = 0.0007). GLP-1RAs plus metformin over metformin alone resulted in a significant weight loss (-5.82 ± 0.69 kg, p < 0.0001), reduction in waist circumference (-4.99 ± 0.6 cm, p < 0.0001), improvement in HbA1c (-0.56% ± 0.13%, p < 0.0001), and fasting plasma glucose (-25.54 ± 3.09 mg/dL, p < 0.0001), increase in total (+41.41 ± 6.11 ng/dL, p < 0.0001) and free (0.44 ± 0.09 ng/dL, p < 0.0001) testosterone levels, and gain in self-reported erectile function (IIEF5 score: +2.26 ± 0.26, p < 0.0001). The gain in the IIEF5 score was more relevant in patients with higher baseline IIEF5 score (estimated coefficient: 0.16 ± 0.08, p = 0.045), those having carotid stenosis (0.50 ± 0.24, p = 0.045), and showing weight loss from baseline (-0.08 ± 0.03, p = 0.013). The leading determinant of the final IIEF5 score was a 1-year treatment with GLP-1RAs plus metformin over metformin alone (2.74 ± 0.53, p < 0.0001).

DISCUSSION

GLP-1RAs plus metformin over metformin alone improved ED regardless of different background characteristics of patients and partially irrespective of therapeutic targets achieved after 12 months of treatment. GLP-1RAs may have induced positive vasculature effects, resulting in improved erectile function in T2D.

CONCLUSION

Due to the retrospective nature of the study, a potential cause-effect relationship between the use of GLP-1RAs plus metformin over metformin alone in improving ED cannot be verified and confirmed. Randomized clinical trials are needed to provide evidence supporting the use of GLP-1RAs for treating ED in T2D.

The anti-inflammatory effect of metformin: The molecular targets

Metformin is an anti-diabetic drug. Metformin mainly inhibits gluconeogenesis in the liver and reduces blood sugar. In addition to the anti-diabetic effects, many studies have revealed that metformin has anti-inflammatory effects. Various molecules were suggested to be the target of the metformin's anti-inflammatory effects. However, the conclusion is not clear. Metformin is related to a number of molecules and the identification of the main target in anti-inflammatory effects leads to the understanding of inflammation and metformin. In this article, I discuss each suggested molecule, involved mechanisms, and their relationship with various diseases.

The effect of pre-dosing with metformin on the insulin response to oral sugar in insulin-dysregulated horses

BACKGROUND

A single dose of metformin administered 1 h prior to oral glucose challenge was previously shown to reduce insulinaemic responses in horses with experimentally-induced insulin dysregulation (ID). Targeted administration could be useful for controlling post-prandial hyperinsulinaemia in horses with naturally-occurring ID.

OBJECTIVES

The objective was to compare the insulinaemic and glycaemic responses to oral sugar testing (OST) performed at different intervals after a single dose of metformin in horses with naturally-occurring ID. We hypothesised that pre-treatment with one dose of metformin would significantly decrease the insulinaemic response to OST.

STUDY DESIGN

Randomised cross-over in vivo experiment.

METHODS

Eight university-owned adult horses with naturally-occurring ID underwent OST 1, 2 and 6 h following a single oral dose of metformin (30 mg/kg) or 1 h after placebo (240 mL water) with a 7-day washout between treatments over a period of 3 weeks. Plasma insulin, C-peptide and glucose concentrations were measured at 0, 60 and 90 min after 0.45 mL/kg light corn syrup and the effect of treatment (and the interval since dosing) examined using a mixed effects linear regression model.

RESULTS

Metformin treatment had no significant effect on plasma glucose, insulin or C-peptide concentrations at any time point compared with placebo (p > 0.05). For OST 1 h post metformin, median (IQR) plasma insulin was 91.3 (62.4-114.9) μIU/mL at 60 min versus 76.2 (59.1-134.5) for placebo (p = 0.8) and 62.7 (31.4-109.7) at 90 min versus 51.8 (29.2-126.3) for placebo (p = 0.9).

MAIN LIMITATIONS

Small sample size may limit identification of more subtle decreases in insulin concentration with metformin pre-dosing. The results of this study are relevant only for one pre-treatment dose (30 mg/kg) which limits extrapolation to predictions about the effects of longer-term metformin administration on insulin and glucose dynamics in the horse.

CONCLUSIONS AND CLINICAL IMPORTANCE

The results do not support the use of targeted metformin treatment to reduce post-prandial hyperinsulinaemia in horses with naturally-occurring ID.

Exploring metformin monotherapy response in Type-2 diabetes: Computational insights through clinical, genomic, and proteomic markers using machine learning algorithms

BACKGROUND

In 2016, the UK had 4.5 million people with diabetes, predominantly Type-2 Diabetes Mellitus (T2DM). The NHS allocates £10 billion (9% of its budget) to manage diabetes. Metformin is the primary treatment for T2DM, but 35% of patients don't benefit from it, leading to complications. This study aims to delve into metformin's efficacy using clinical, genomic, and proteomic data to uncover new biomarkers and build a Machine Learning predictor for early metformin response detection.

METHODS

Here we report analysis from a T2DM dataset of individuals prescribed metformin monotherapy from the Diastrat cohort recruited at the Altnagelvin Area Hospital, Northern Ireland.

RESULTS

In the clinical data analysis, comparing responders (those achieving HbA1c ≤ 48 mmol/mol) to non-responders (with HbA1c > 48 mmol/mol), we identified that creatinine levels and bodyweight were more negatively correlated with response than non-response. In genomic analysis, we identified statistically significant (p-value <0.05) variants rs6551649 (LPHN3), rs6551654 (LPHN3), rs4495065 (LPHN3) and rs7940817 (TRPC6) which appear to differentiate the responders and non-responders. In proteomic analysis, we identified 15 statistically significant (p-value <0.05, q-value <0.05) proteomic markers that differentiate controls, responders, non-responders and treatment groups, out of which the most significant were HAOX1, CCL17 and PAI that had fold change ∼2. A machine learning model was build; the best model predicted non-responders with 83% classification accuracy.

CONCLUSION

Further testing in prospective validation cohorts is required to determine the clinical utility of the proposed model.

Comparison between the effect of Empagliflozin and Pioglitazone added to metformin in patients with type 2 diabetes and nonalcoholic fatty liver disease

BACKGROUND/AIMS

Non-alcoholic fatty liver disease (NAFLD), defined as the accumulation of >5% fat in the liver, is the most frequently co-exist disease with diabetics up to 70%. Current study was conducted to compare efficacy of combination therapy of empagliflozin (EMPA) or pioglitazone (PGZ) with metformin (MET) in patients with T2DM and NAFLD.

METHODS

In this open label, prospective clinical trial, sixty patients were randomly assigned to receive EMPA 10 mg/day or PGZ 30 mg/day in combination Metformin (at least 1500 mg) for six months. NAFLD grade and liver stiffness were defined and measured at the beginning and after 6 months. As the secondary outcomes, anthropometric characteristics, lipid profile, plasma glucose test, and liver enzymes test were measured at the baseline and endpoint.

RESULTS

The results showed that both combination therapy with EMPA+ MET or PGZ+MET significantly reversed fibrosis stage of NAFLD (P<0.05). Significant reduction in lipid profile test, and liver enzymes test were seen in both groups (P<0.05). However, the greater reduction in waist circumference was observed in EMPA groups compared to PGZ (-4.4 ± 2.39 vs -2.05±1.28, p<0.001), meanwhile weight and BMI decreased significantly only in the patients receiving EMPA (-5.78 ± 3.6 kg vs 0.93 ± 0.33 kg and -2.01± 3.19 kg/m2 vs 0.33 ± 0.12 kg/m2, respectively, P<0.001).

CONCLUSION

combination of EMPA or PGZ with metformin equally improved liver fibrosis stage and stiffness in T2DM patients with NAFLD. The improvements of laboratory tests were observed in the both groups, while, regarding weight reduction, only the regimen containing EMPA was effective.

Predicting Conversion to Insulin Sensitivity With Metformin: A Promising Tool for Clinicians in Addressing Insulin Resistance and Improving Outcomes in Patients With Treatment Resistant Bipolar Depression

BACKGROUND

Insulin resistance (IR) changes the trajectory of responsive bipolar disorder to a treatment-resistant course. A clinical trial conducted by our group demonstrated that IR reversal by metformin improved clinical and functional outcomes in treatment-resistant bipolar depression (TRBD). To aid clinicians identify which metformin-treated TRBD patients might reverse IR, and given strong external evidence for their association with IR, we developed a predictive tool using body mass index (BMI) and homeostatic model assessment-insulin resistance (HOMA-IR).

METHODS

The predictive performance of baseline BMI and HOMA-IR was tested with a logistic regression model using known metrics: area under the receiver operating curve, sensitivity, and specificity. In view of the high benefit to low risk of metformin in reversing IR, high sensitivity was favored over specificity.

RESULTS

In this BMI and HOMA-IR model for IR reversal, the area under the receiver operating curve is 0.79. At a cutoff probability of conversion of 0.17, the model's sensitivity is 91% (95% confidence interval [CI], 57%-99%), and the specificity is 56% (95% CI, 36%-73%). For each unit increase in BMI or HOMA-IR, there is a 15% (OR, 0.85; 95% CI, 0.71-0.99) or 43% (OR, 0.57; CI, 0.18-1.36) decrease in the odds of conversion, respectively.

CONCLUSIONS

In individuals with TRBD, this tool using BMI and HOMA-IR predicts IR reversal with metformin with high sensitivity. Furthermore, these data suggest early intervention with metformin at lower BMI, and HOMA-IR would likely reverse IR in TRBD.

Metformin and risk of hematological cancers in patients with diabetes: a systematic review and meta-analysis

FUNDING

No external funding.

Cardiovascular/anti-inflammatory drugs repurposed for treating or preventing cancer: A systematic review and meta-analysis of randomized trials

BACKGROUND

Due to encouraging pre-clinical data and supportive observational studies, there has been growing interest in applying cardiovascular drugs (including aspirin, angiotensin-converting enzyme [ACE] inhibitors, statins, and metformin) approved to treat diseases such as hypertension, hyperlipidemia, and diabetes mellitus to the field of oncology. Moreover, given growing costs with cancer care, these medications have offered a potentially more affordable avenue to treat or prevent recurrence of cancer. We sought to investigate the anti-cancer effects of drugs repurposed from cardiology or anti-inflammatories to treat cancer. We specifically evaluated the following drug classes: HMG-CoA reductase inhibitors (statins), cyclo-oxygenase inhibitors, aspirin, metformin, and both angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors. We also included non-steroidal anti-inflammatory drugs (NSAIDs) because they exert a similar mechanism to aspirin by blocking prostaglandins and reducing inflammation that is thought to promote the development of cancer.

METHODS

We performed a systematic literature review using PubMed and Web of Science with search terms including "aspirin," "NSAID," "statin" (including specific statin drug names), "metformin," "ACE inhibitors," and "ARBs" (including specific anti-hypertensive drug names) in combination with "cancer." Searches were limited to human studies published between 2000 and 2023.

MAIN OUTCOMES AND MEASURES

The number and percentage of studies reported positive results and pooled estimates of overall survival, progression-free survival, response, and disease-free survival.

RESULTS

We reviewed 3094 titles and included 67 randomized clinical trials. The most common drugs that were tested were metformin (n = 21; 30.9%), celecoxib (n = 20; 29.4%), and simvastatin (n = 8; 11.8%). There was only one study that tested cardiac glycosides and none that studied ACE inhibitors. The most common tumor types were non-small-cell lung cancer (n = 19; 27.9%); breast (n = 8; 20.6%), colorectal (n = 7; 10.3%), and hepatocellular (n = 6; 8.8%). Most studies were conducted in a phase II trial (n = 38; 55.9%). Most studies were tested in metastatic cancers (n = 49; 72.1%) and in the first-line setting (n = 36; 521.9%). Four studies (5.9%) were stopped early because of difficulty with accrual. The majority of studies did not demonstrate an improvement in either progression-free survival (86.1% of studies testing progression-free survival) or in overall survival (94.3% of studies testing overall survival). Progression-free survival was improved in five studies (7.4%), and overall survival was improved in three studies (4.4%). Overall survival was significantly worse in two studies (3.8% of studies testing overall survival), and progression-free survival was worse in one study (2.8% of studies testing progression-free survival).

CONCLUSIONS AND RELEVANCE

Despite promising pre-clinical and population-based data, cardiovascular drugs and anti-inflammatory medications have overall not demonstrated benefit in the treatment or preventing recurrence of cancer. These findings may help guide future potential clinical trials involving these medications when applied in oncology.

Survival Impact of Combined Biguanide and Temozolomide in Glioblastoma Preclinical Models: A Systematic Review and Meta-Analysis

BACKGROUND

Glioblastoma (GBM) is an aggressive tumor known for its poor prognosis. Despite extensive research into its molecular and clinical aspects, the current management strategies have shown limited efficacy in improving survival rate. Despite some preclinical studies exploring the combination of temozolomide (TMZ) with biguanides such as metformin (MET) and others, the potential benefits of this combination remain uncertain. The aim of this study is to evaluate the overall survival (OS) in GBM murine-models treated with a combination of TMZ + biguanide compared to those treated with TMZ alone.

METHODS

We systematically searched Medline, Embase, and Lilacs databases for studies comparing TMZ + biguanide versus TMZ alone in GBM models and reporting OS data. The mean difference (MD) with 95% confidence interval and random-effects model was adopted.

RESULTS

Nine studies were included in this systematic review. The meta-analysis comprised 6 studies involving 85 rat-models, with 45 subjects undergoing combined-treatment. GBM-murine models treated with TMZ + biguanide exhibited notably superior OS rates compared to those who received TMZ alone, showing an MD of 21.0 days (6.9-35.0). Within the subgroup of orthotopic models, the OS was also significantly better in combination-therapy with an MD of 23.7 days (6.5-40.9). Similarly, in the subgroup where MET was used as biguanide therapy, TMZ + MET demonstrated a significant increase in OS, with an MD of 27.4 days (6.0-48.8). In immunocompromised models, the combination-therapy also exhibited higher survival rates, with an MD of 13 days (9.4-16.6).

CONCLUSIONS

This systematic review and meta-analysis provide compelling evidence regarding the beneficial effects of TMZ + biguanide in GBM models compared with TMZ alone, resulting in a significant improvement in OS.

Pasireotide effects on biochemical control and glycometabolic profile in acromegaly patients switched from combination therapies or unconventional dosages of somatostatin analogs

PURPOSE

To evaluate the impact of pasireotide (PAS) therapy on hormonal and glycometabolic outcome in patients with acromegaly previously treated with combination medical therapies or unconventional dosages of first-generation somatostatin receptor ligands (fg-SRLs).

METHODS

Retrospective study carried out in two referral centers for pituitary diseases. Twenty-one acromegalic patients were switched to PAS (12 had biochemical control, 9 were uncontrolled). Data were collected after 3- and 6-months PAS treatment, and at the last available visit (median 35 months).

RESULTS

After switching to PAS therapy, a significant reduction in IGF-1 values was observed [median 39%; 0.79 xULN (IQR 0.5-1.01) vs 1.29 xULN (IQR 1.06-1.83); p = 0.009]. IGF-1 reduction was statistically significant in the 9 patients previously uncontrolled (61%, p = 0.016), and in the 12 controlled subjects (33%, p = 0.037). At last follow-up, the number of patients reaching an acceptable biochemical control (IGF-1 < 1.3 xULN) raised from 57 to 90% (p = 0.032). Mean HbA1c levels increased from 5.7% (5.5-5.9) to 6.0% (5.9-7) (p = 0.002), and the percentage of diabetic patients raised from 14% (3/21) to 67% (14/21) (p = 0.004). At the last evaluation HbA1c was ≥ 7.0% in 5 patients (24%). Antidiabetic drugs were initiated in 9 new patients, and in 7 out of 9 metformin alone was effective. Younger age and male sex were predictors for the maintenance of glucose homeostasis.

CONCLUSION

PAS monotherapy can be effective in acromegalic patients previously treated with combination medical therapies or unconventional dosages of fg-SRLs. Glucose imbalance can be managed in the vast majority of cases by use of lifestyle interventions and metformin.

Associations of metformin therapy treatment with endometrial cancer risk and prognosis: A systematic review and meta-analysis

BACKGROUND

Several abstract studies have demonstrated that metformin may be beneficial for preventing and treating endometrial cancer (EC), while the results have been inconsistent and inconclusive. This systematic review and meta-analysis aimed to investigate the association between metformin use and the incidence and mortality of endometrial cancer in diabetic patients.

METHODS

A systematic literature search was performed in Pubmed, EMBASE, Web of Science, Cochrane Library, SinoMed, CNKI, Wanfang Data, and VIP from inception to November 2022. The outcome measures were hazard ratios (HRs) comparing the EC incidence and mortality in patients with type 2 diabetes mellitus (T2DM) on metformin and non-metformin. A random or fixed-effects model was applied for data analysis, and subgroup analysis was performed to look for factors of heterogeneity. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessed the evidence's certainty.

RESULTS

Eleven studies reported data on EC incidence. The pooled results suggested that the use of metformin was associated with a significantly higher incidence of EC (HR = 1.17, 95% CI 1.09-1.26, P < 0.0001). Further, seventeen studies were included for survival analysis. The pooled data showed that metformin could significantly decrease all-cause mortality (HR = 0.62, 95% CI 0.52-0.74, P < 0.00001) and endometrial cancer-specific mortality (HR = 0.95, 95% CI 0.90, 1.00, P = 0.03). Finally, we noted that metformin was associated with significantly improving the progression-free survival (PFS) of EC patients with T2DM (HR = 0.55, 95% CI 0.44, 0.68, P < 0.00001).

CONCLUSIONS

This meta-analysis did not prove that metformin was beneficial for preventing EC. However, metformin could reduce their mortality risk and prolong the progression-free survival time of EC patients with T2DM.