Metformin: time to review its role and safety in chronic kidney disease

Metformin and risk factors for chronic kidney disease in a European population based on Mendelian randomization

BACKGROUND

Metformin, widely used for type 2 diabetes, raises concerns about its use in chronic kidney disease (CKD) due to risks like lactic acidosis and renal function impact. This study uses Mendelian randomization (MR) and summary data-based MR (SMR) to explore metformin's potential causal relationship with CKD and associated genes.

METHODS

We employed MR methods (MR-Egger, weighted median, IVW) and sensitivity analyses to explore the causal relationship between metformin and CKD. SMR was used to analyze eQTL and CKD data from the UK Biobank and FinnGen, intersecting these with metformin drug targets to identify genes associated with CKD.

RESULTS

MR analysis indicated that metformin may increase CKD risk (IVW model: OR = 144.67, p < 0.01). However, given the high OR value, additional studies are warranted to validate this finding. SMR identified genes ANPEP, STK11, ACACB, and RPS6KB as significantly associated with CKD risk.

CONCLUSION

The study suggests metformin could elevate CKD risk and identifies relevant genes. Clinicians should exercise caution when prescribing metformin, particularly for patients with renal issues. Further research is needed to confirm these findings and guide clinical practices.

Research Progress of Traditional Chinese Medicine in Adjuvant Treatment of Type 1 Diabetes

Type 1 diabetes (T1DM) is one of the most common chronic metabolic diseases in the world. Insulin replacement therapy and drug adjuvant therapy are the main means of modern medical treatment of T1DM; still, there are adverse reactions such as drug resistance, which seriously hinder the therapeutic effect. As a unique medical method in China, traditional Chinese medicine (TCM) has a significant effect on the treatment of T1DM. TCM therapy can reduce the symptoms of T1DM, prevent complications, improve insulin resistance, and promote insulin secretion. In recent years, the research field of TCM in the treatment of T1DM has made considerable progress. The research on the treatment of T1DM by Chinese herbal medicine, TCM prescription, acupuncture, and moxibustion shows good anti-T1DM effect and significantly improves the survival rate of patients. This article aims to summarize the methods of TCM in the treatment of T1DM, expounds on the mechanism of action in the treatment of T1DM, and discusses the limitations and opportunities of TCM in the treatment of T1DM.

Metformin alleviates sphingolipids dysregulation and improves obesity-related kidney disease in high-fat diet rats

Obesity-related kidney disease (ORKD) has recently become a global health issue. Metformin is widely used in patients with type 2 diabetes with concomitant obesity, but its effects on ORKD are insufficiently understood. Accumulation of lipid species including sphingolipids has been reported to disrupt glomerular functions and drive progression of chronic kidney disease. The present study aimed to test the hypothesis that metformin could exert beneficial effects on ORKD, which may be associated with changes in renal lipidomics. Male Sprague-Dawley rats were divided into normal chow diet (ND) group or high-fat diet (HFD)-fed group. After 8 weeks, HFD-fed group was subdivided into metformin treatment (HFD-Met) group and control (HFD-C) group for an additional 8 weeks. Sphingolipids and phospholipids in renal cortex were measured by targeted lipidomics. Compared with ND group, HFD-C group developed histopathological features of ORKD. Metformin alleviated dyslipidemia, renal dysfunction, proteinuria, glomerular hypertrophy, podocyte damage, and renal fibrosis in HFD-fed rats. Renal sphingolipid analysis showed elevations of total ceramide, sphingosine, glucosylceramide, and galactosylceramide levels in HFD-C versus ND group. Specific species, such as ceramide d18:1/22:0, glucosylceramide d18:1/20:0, and galactosylceramide d18:1/16:0, which were positively associated with oxidative stress and insulin resistance, were reduced in HFD-Met versus HFD-C group. Renal phospholipid analysis showed increased levels of total phosphatidylcholine and lysophosphatidylcholine (LPC) in HFD-C rats versus ND rats. The ratio of saturated and monounsaturated LPCs to polyunsaturated LPCs was significantly reduced in HFD-Met rats. These results suggest that metformin alleviates sphingolipids dysregulation and improves ORKD in HFD-fed rats. SIGNIFICANCE STATEMENT: To date, this is the first report to explore effects of metformin on renal lipidomics. These findings reveal specific changes of renal lipid species, which are crucial for deeper understanding the underlying mechanisms of obesity-related kidney disease and effects of metformin on it. The associated signature sphingolipids and phospholipids in the study may have significant implications for developing targeted therapeutic strategies for obesity-related kidney disease.

Aerobic Exercise and Metformin: A Dual Approach to Enhancing Glycemic Maintenance in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a widespread metabolic condition characterized by elevated glucose levels followed by deficiency in insulin secretion. Metformin notably decreased the incidence of T2DM by 31% and it exerts its effects through various signaling pathways. Databases searched included PubMed, Google Scholar, and Scopus from 2000 to 2024. One of the primary mechanisms involves AMPK activation which causes reduced lipogenesis and improved fatty acid oxidation in the liver and muscles. Key molecules affected by metformin include acetyl-CoA carboxylase (ACC) and sterol regulatory element-binding protein 1c (SREBP-1c), both involved in lipid synthesis regulation. Aerobic exercise has also emerged as a crucial component in managing T2DM due to its improved effects on hyperglycemia and insulin sensitivity. Key signaling pathways affected in T2DM include the PI3K/Akt, AMP-activated protein kinase (AMPK), and MAPK/ERK pathways which play essential roles in regulating glucose homeostasis, glycogenesis, and insulin secretion. When comparing the mechanisms and efficacy of aerobic exercise and metformin, it becomes evident that aerobic exercise primarily enhances physical fitness and metabolic function, while metformin exerts its effects through biochemical pathways involving AMPK activation. Aerobic exercise and metformin are effective for managing T2DM, though they operate through different mechanisms. Regular aerobic exercise improves insulin sensitivity, enhances cardiovascular health, and promotes weight loss, while metformin primarily decreases hepatic gluconeogenesis and enhances insulin secretion. Understanding the intricate signaling pathways affected by metformin and aerobic exercise provides valuable insights into its mechanisms of action and clinical implications for treating diabetic patients effectively.

Oral administration of herbal oligonucleotide drug JGL-sRNA-h7 ameliorates hyperglycemia in db/db mice and beagle dogs

Type 2 diabetes mellitus is a prevalent metabolic disease, posing a considerable threat to public health. Oligonucleotide drugs have proven to be a promising field of therapy for the diseases. In this study, we reported that a herbal small RNA (sRNA), JGL-sRNA-h7 (B34735529, F1439.L002444.A11), could exhibit potent hypoglycemic effects by targeting glucose-6-phosphatase. Oral administration of sphingosine (d18:1)-JGL-sRNA-h7 bencaosomes ameliorated hyperglycemia and diabetic kidney injury better than metformin in db/db mice. Furthermore, glucose tolerance was also improved in sphingosine (d18:1)-JGL-sRNA-h7 bencaosomes-treated beagle dogs. Our study indicates that JGL-sRNA-h7 could be a promising hypoglycemic oligonucleotide drug.

A glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy

Diabetic nephropathy is a severe complication of diabetes. Treatment of diabetic nephropathy is an important challenge due to persistent hyperglycemia and elevated levels of reactive oxygen species (ROS) in the kidney. Herein, we designed a glycopolymersome that can treat type 2 diabetic nephropathy by effectively inhibiting hyperglycemia and ROS-associated diabetic nephropathy pathogenesis. The glycopolymersome is self-assembled from phenylboronic acid derivative-containing copolymer, poly(ethylene oxide)45-block-poly[(aspartic acid)13-stat-glucosamine24-stat-(phenylboronic acid)18-stat-(phenylboronic acid pinacol ester)3] [PEO45-b-P(Asp13-stat-GA24-stat-PBA18-stat-PAPE3)]. PBA segment can reversibly bind blood glucose or GA segment for long-term regulation of blood glucose levels; PAPE segment can scavenge excessive ROS for renoprotection. In vitro studies confirmed that the glycopolymersomes exhibit efficient blood glucose responsiveness within 2 h and satisfactory ROS-scavenging ability with 500 μM H2O2. Moreover, the glycopolymersomes display long-acting regulation of blood glucose levels in type 2 diabetic nephropathy mice within 32 h. Dihydroethidium staining revealed that these glycopolymersomes reduced ROS to normal levels in the kidney, which led to 61.7% and 76.6% reduction in creatinine and urea levels, respectively, along with suppressing renal apoptosis, collagen accumulation, and glycogen deposition in type 2 diabetic nephropathy mice. Notably, the polypeptide-based glycopolymersome was synthesized by ring-opening polymerization (ROP) of N-carboxyanhydrides (NCAs), thereby exhibiting favorable biodegradability. Overall, we proposed a new glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy, which could be extended to encompass the design of various multifunctional nanoparticles targeting diabetes and its associated complications.

National trends in utilisation of glucose lowering medicines by older people with diabetes in long-term care facilities

AIMS

To examine national trends in glucose lowering medicine (GLM) use among older people with diabetes in long-term care facilities (LTCFs) during 2009-2019.

METHODS

A repeated cross-sectional study of individuals ≥65 years with diabetes in Australian LTCFs (n = 140,322) was conducted. Annual age-sex standardised prevalence of GLM use and number of defined daily doses (DDDs)/1000 resident-days were estimated. Multivariable Poisson or Negative binomial regression models were used to estimate adjusted rate ratios (aRRs) and 95 % confidence intervals (CIs).

RESULTS

Prevalence of GLM use remained steady between 2009 (63.9%, 95 %CI 63.3-64.4) and 2019 (64.3%, 95 %CI 63.9-64.8) (aRR 1.00, 95 %CI 1.00-1.00). The percentage of residents receiving metformin increased from 36.0% (95 %CI 35.3-36.7) to 43.5% (95 %CI 42.9-44.1) (aRR 1.01, 95 %CI 1.01-1.01). Insulin use also increased from 21.5% (95 %CI 21.0-22.0) to 27.0% (95 %CI 26.5-27.5) (aRR 1.02, 95 %CI 1.02-1.02). Dipeptidyl peptidase-4 inhibitor use increased from 1.0% (95 %CI 0.9-1.1) to 21.1% (95 %CI 20.7-21.5) (aRR 1.24, 95 %CI 1.24-1.25), while sulfonylurea use decreased from 34.4% (95 %CI 33.8-35.1) to 19.3% (95 %CI 18.9-19.7) (aRR 0.93, 95 %CI 0.93-0.94). Similar trends were observed in DDDs/1000 resident days.

CONCLUSIONS

The increasing use of insulin and ongoing use of sulfonylureas suggests a need to implement evidence-based strategies to optimise diabetes care in LTCFs.

Prescribing Renally Inappropriate Medication to Hospitalized Geriatric Patients in Makkah, Saudi Arabia

Introduction

As a result of the physiological decline in renal function that comes with age and the common failure to recognise renal insufficiency, older adults aged 65 and above are at increased risk of receiving medications that are inappropriate for their level of renal function which in turn lead to increased risk of adverse effects. Little is known about how many older adults receive medications that are inappropriate for their level of renal function. This study aimed to determine the prevalence of renally inappropriate medications in elderly adults by reviewing patient files and evaluating the appropriateness of medication doses relative to renal function in patients aged ≥ 65 years at inpatient healthcare departments.

Methods

A retrospective cross-sectional study of patients aged ≥ 65 years was conducted, covering cases from 2015 to 2021. Patient's medical records were reviewed, their renal function and medications lists were evaluated, determined whether they had been prescribed at least one renally inappropriate medication based on drug-dosing recommendations for different degrees of renal function.

Results

A total of 317 elderly inpatients were included, 10% of whom had received inappropriate doses relative to their renal function. Glomerular filtration rate was associated with inappropriate dosing in this study. Of the patients CKD stage 5, 36.8% had at least one drug administered at an inappropriate dose, while this figure was 6.5% among the patients at CKD stage 1; this difference was statistically significant (p = 0.001).

Conclusion

A notable portion of older adults may be at risk of adverse effects due to inappropriate medication dosing related to their renal function. Further studies with large samples, drug use analyses based on comprehensive geriatric references and a prioritisation of actual outcomes over potential outcomes are needed to further determine elderly adults' exposure to inappropriate drugs.

Renally Inappropriate Medications in the Old Population: Prevalence, Risk Factors, Adverse Outcomes, and Potential Interventions

Like most organs, the renal system decreases in function as we age. In the elderly, chronic kidney disease is common. When patients with chronic kidney disease take nephrotoxic medications, they are more likely to suffer adverse drug reactions, be hospitalized, and spend an extended period in the hospital. Calculating the renal clearance of a drug dose based on its glomerular filtration rate, or creatinine clearance, is necessary. Multiple tools are available for identifying renally inappropriate medications (RIMs). RIM prescriptions can be influenced by various factors, which vary according to the study. A higher number of medications means a higher likelihood of using RIMs. Numerous studies have investigated RIMs. The most contraindicated drug in renal insufficiency patients was a non-steroidal anti-inflammatory medication. A variety of interventions have been used to reduce RIM prescriptions to varying degrees of success.

Repurposing Metformin in hematologic tumor: State of art

Metformin is an ancient drug for the treatment of type 2 diabetes, and many studies now suggested that metformin can be used as an adjuvant drug in the treatment of many types of tumors. The mechanism of action of metformin for tumor treatment mainly involves: 1. activation of AMPK signaling pathway 2. inhibition of DNA damage repair in tumor cells 3. downregulation of IGF-1 expression 4. inhibition of chemoresistance and enhancement of chemotherapy sensitivity in tumor cells 5. enhancement of antitumor immunity 6. inhibition of oxidative phosphorylation (OXPHOS). Metformin also plays an important role in the treatment of hematologic tumors, especially in leukemia, lymphoma, and multiple myeloma (MM). The combination of metformin and chemotherapy enhances the efficacy of chemotherapy, and metformin reduces the progression of monoclonal gammopathy of undetermined significance (MGUS) to MM. The purpose of this review is to summarize the anticancer mechanism of metformin and the role and mechanism of action of metformin in hematologic tumors. We mainly summarize the studies related to metformin in hematologic tumors, including cellular experiments and animal experiments, as well as controlled clinical studies and clinical trials. In addition, we also focus on the possible side effects of metformin. Although a large number of preclinical and clinical studies have been performed and the role of metformin in preventing the progression of MGUS to MM has been demonstrated, metformin has not been approved for the treatment of hematologic tumors, which is related to the adverse effects of its high-dose application. Low-dose metformin reduces adverse effects and has been shown to alter the tumor microenvironment and enhance antitumor immune response, which is one of the main directions for future research.

The Effect and Safety Assessment of Metformin and DLBS3233 (A Bioactive Fraction of Lagerstroemia speciosa and Cinnamomum burmannii) on Improving Metabolic Parameters in Women with Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) can lead to compensatory hyperinsulinemia with consequent metabolic abnormalities in women. In this study, DLBS3233 and Metformin were used to be tested. DLBS3233 itself is the new insulin-sensitizing drug, a combination-bioactive-fraction derived from two Indonesian herbals, Lagerstroemia speciosa and Cinnamomum burmannii. DLBS3233 alone and in combination with metformin were evaluated for efficacy and safety in insulin-resistant women with polycystic ovary syndrome (PCOS).

Methods

A randomized, double-blind, 3-arm, double-dummy, non-inferiority, and also a controlled clinical study was conducted at the Dr. Kariadi Hospital, Indonesia, between October 2014 and February 2019. The study involved 60 female subjects (with 20 female subjects in each group) that had polycystic ovary syndrome (PCOS).Treatment I consists of one placebo capsule twice per day and one 100 mg DLBS3233 capsule once per day. Treatment II consists of one placebo caplet once per day and one 750 mg Metformin XR caplet twice per day. Treatment III consists of one 750 mg Metformin XR caplet twice per day and one 100 mg DLBS3233 capsule once per day.

Results

In treatment I, the homeostatic model assessment for insulin resistance (HOMA-IR) levels were 3.55, 3.59, and 3.80 at pretest, 3 months, and 6 months after intervention, respectively. In treatment II, the HOMA-IR level were 4.00, 2.21, and 4.40 at pretest, 3 months, and 6 months after intervention respectively. In treatment III, the HOMA-IR levels were 3.30, 2.86, and 3.12 at pretest, 3 months, and 6 months after intervention, respectively. There was no apparent difference existed in the fasting plasma glucose (FPG), high-density lipoprotein (HDL), triglycerides, ferriman-gallwey scores (FGS), and safety assessment on vital signs and laboratory examinations (liver function and renal function) in all groups.

Conclusion

Either DLBS3233 alone or the DLBS3233/Metformin combination showed no significant efficacy and did not negatively affect cardiovascular function, liver and kidney function in PCOS subjects.

ClinicalTrialsgov Identifier

NCT01999686 Date: 3rd of December, 2013.

Bioactive compounds from Polygonatum genus as anti-diabetic agents with future perspectives

Diabetes mellitus (DM) is one of the most serious health problems worldwide. Species in the genus Polygonatum are traditional food and medicinal plants, which play an important role in controlling blood glucose. In this reveiw, we systematically summarized the traditional and modern applications of the genus Polygonatum in DM, focused on the material bases of polysaccharides, flavonoids and saponins. We highlighted their mechanisms of action in preventing obese diabetes, improving insulin resistance, promoting insulin secretion, regulating intestinal microecology, inhibiting advanced glycation end products (AGEs) accumulation, suppressing carbohydrate digestion and obsorption and modulating gluconeogenesis. Based on the safety and efficacy of this 'medicinal food' and its utility in the prevention and treatment of diabetes, we proposed a research and development program that includs diet design (supplementary food), medical nutrition therapy and new drugs, which could provide new pathways for the use of natural plants in prevention and treatment of DM.

ChREBP-β/TXNIP aggravates frucose-induced renal injury through triggering ferroptosis of renal tubular epithelial cells

High fructose intake is an essential risk factor for kidney injury. However, the specific mechanism underlying high fructose-induced kidney injury remains unclarified. Carbohydrate response element-binding protein (ChREBP) is a key transcriptional activator that regulates fructose metabolism. ChREBP-β exhibits sustained activity due to the lack of a low glucose inhibitory domain, and is thus described as the active form of ChREBP. In this study, a mouse model with specific overexpression of ChREBP-β in the renal tubule was established by using the Cre/LoxP method. Quantitative proteomic analysis and experimental verification results suggest that ChREP-β overexpression leads to ferroptosis of renal tubular epithelial cells and kidney injury. ChREPB-β promotes the gene transcription of thioredoxin-interacting protein (TXNIP) and thereby increases its expression level. TXNIP is associated with activation of ferroptosis. TXNIP can initiate ferroptosis and eventually contribute to high fructose-induced renal tubular epithelial cell damage. Through down-regulating ChREBP-β, metformin can inhibit gene transcription of TXNIP, attenuate high fructose-induced ferroptosis in renal tubular epithelial cells, and alleviate kidney injury. In conclusion, ChREBP-β mediates fructose-induced ferroptosis of renal tubular epithelial cells, and metformin with a ChREBP-β inhibitory effect may be a potential treatment for ferroptosis of renal tubular epithelial cells.

Action Mechanism of Metformin and Its Application in Hematological Malignancy Treatments: A Review

Hematologic malignancies (HMs) mainly include acute and chronic leukemia, lymphoma, myeloma and other heterogeneous tumors that seriously threaten human life and health. The common effective treatments are radiotherapy, chemotherapy and hematopoietic stem cell transplantation (HSCT), which have limited options and are prone to tumor recurrence and (or) drug resistance. Metformin is the first-line drug for the treatment of type 2 diabetes (T2DM). Recently, studies identified the potential anti-cancer ability of metformin in both T2DM patients and patients that are non-diabetic. The latest epidemiological and preclinical studies suggested a potential benefit of metformin in the prevention and treatment of patients with HM. The mechanism may involve the activation of the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway by metformin as well as other AMPK-independent pathways to exert anti-cancer properties. In addition, combining current conventional anti-cancer drugs with metformin may improve the efficacy and reduce adverse drug reactions. Therefore, metformin can also be used as an adjuvant therapeutic agent for HM. This paper highlights the anti-hyperglycemic effects and potential anti-cancer effects of metformin, and also compiles the in vitro and clinical trials of metformin as an anti-cancer and chemosensitizing agent for the treatment of HM. The need for future research on the use of metformin in the treatment of HM is indicated.

The molecular mechanisms and intervention strategies of mitophagy in cardiorenal syndrome

Cardiorenal syndrome (CRS) is defined as a disorder of the heart and kidney, in which acute or chronic injury of one organ may lead to acute or chronic dysfunction of the other. It is characterized by high morbidity and mortality, resulting in high economic costs and social burdens. However, there is currently no effective drug-based treatment. Emerging evidence implicates the involvement of mitophagy in the progression of CRS, including cardiovascular disease (CVD) and chronic kidney disease (CKD). In this review, we summarized the crucial roles and molecular mechanisms of mitophagy in the pathophysiology of CRS. It has been reported that mitophagy impairment contributes to a vicious loop between CKD and CVD, which ultimately accelerates the progression of CRS. Further, recent studies revealed that targeting mitophagy may serve as a promising therapeutic approach for CRS, including clinical drugs, stem cells and small molecule agents. Therefore, studies focusing on mitophagy may benefit for expanding innovative basic research, clinical trials, and therapeutic strategies for CRS.

The effect of metformin on ameliorating neurological function deficits and tissue damage in rats following spinal cord injury: A systematic review and network meta-analysis

Spinal cord injury (SCI) is a devastating condition with few treatment options. Metformin, a classical antidiabetic and antioxidant, has extended its application to experimental SCI treatment. Here, we performed a systematic review to evaluate the neurobiological roles of metformin for treating SCI in rats, and to assess the potential for clinical translation. PubMed, Embase, China National Knowledge Infrastructure, WanFang data, SinoMed, and Vip Journal Integration Platform databases were searched from their inception dates to October 2021. Two reviewers independently selected controlled studies evaluating the neurobiological roles of metformin in rats following SCI, extracted data, and assessed the quality of methodology and evidence. Pairwise meta-analyses, subgroup analyses and network analysis were performed to assess the roles of metformin in neurological function and tissue damage in SCI rats. Twelve articles were included in this systematic review. Most of them were of moderate-to-high methodological quality, while the quality of evidence from those studies was not high. Generally, Basso, Beattie, and Bresnahan scores were increased in rats treated with metformin compared with controls, and the weighted mean differences (WMDs) between metformin and control groups exhibited a gradual upward trend from the 3rd (nine studies, n = 164, WMD = 0.42, 95% CI = −0.01 to 0.85, P = 0.06) to the 28th day after treatment (nine studies, n = 136, WMD = 3.48, 95% CI = 2.04 to 4.92, P < 0.00001). Metformin intervention was associated with improved inclined plane scores, tissue preservation ratio and number of anterior horn motor neurons. Subgroup analyses indicated an association between neuroprotection and metformin dose. Network meta-analysis showed that 50 mg/kg metformin exhibited greater protection than 10 and 100 mg/kg metformin. The action mechanisms behind metformin were associated with activating adenosine monophosphate-activated protein kinase signaling, regulating mitochondrial function and relieving endoplasmic reticulum stress. Collectively, this review indicates that metformin has a protective effect on SCI with satisfactory safety and we demonstrate a rational mechanism of action; therefore, metformin is a promising candidate for future clinical trials. However, given the limitations of animal experimental methodological and evidence quality, the findings of this pre-clinical review should be interpreted with caution.

The extrapyramidal syndromes of chronic kidney disease and dialysis (EPS-CKDD): diagnostic criteria, risk factors and prognosis

BACKGROUND

Acute extrapyramidal movement disorders in dialysis patients are rare, inconsistently defined and have uncertain aetiology and prognosis.

AIM

Define diagnostic criteria, prognosis and risk factors.

DESIGN AND METHODS

Retrospective case series review of 20 patients (14 female, mean age 62 years) receiving dialysis for a median of 15 (interquartile range 4-35) months who presented with acute parkinsonism (AP = 11) or chorea/athetosis (CA = 9).

RESULTS

All patients had type 2 diabetes (HbA1c 6.8 ± 1.0) and had received metformin. Lactic acidosis was present in 2 patients at presentation and serum lactate was elevated in 7/15 patients tested. No patient had abnormal copper or thyroid metabolism and 5/8 patients tested returned marginal abnormalities in heavy metal screening. Magnetic resonance imaging (MRI) revealed characteristic bilateral symmetric T2 hyperintensity of the basal ganglia (BG), predominantly putamen and globus pallidus (the lentiform nucleus) and more extensive involvement of the external and internal capsules in patients with AP presentation. Post-mortem demonstrated cytotoxic necrosis of the BG. Therapy included thiamine, intensive dialysis and cessation of metformin. Two patients died acutely, nine recovered and nine had residual symptoms. Median survival did not differ by presentation: AP 24 [95% confidence interval (CI) 21-27] and CA 33 (95% CI 32-35) months, P = 0.21.

CONCLUSIONS

There are two distinct clinical extrapyramidal movement disorders associated with specific diagnostic MRI imaging that support the diagnosis of the extrapyramidal syndromes of chronic kidney disease and dialysis. The associations with diabetes, metformin and metabolic acidosis suggest a common pathogenic mechanism but require additional study. Early recognition and treatment may improve outcomes.

Protocol for the Metformin Aneurysm Trial (MAT): a placebo-controlled randomised trial testing whether metformin reduces the risk of serious complications of abdominal aortic aneurysm

Background

Multiple observational studies have associated metformin prescription with reduced progression of abdominal aortic aneurysm (AAA). The Metformin Aneurysm Trial (MAT) will test whether metformin reduces the risk of AAA rupture-related mortality or requirement for AAA surgery (AAA events) in people with asymptomatic aneurysms.

Methods

MAT is an international, multi-centre, prospective, parallel-group, randomised, placebo-controlled trial. Participants must have an asymptomatic AAA measuring at least 35 mm in maximum diameter, no diabetes, no contraindication to metformin and no current plans for surgical repair. The double-blind period is preceded by a 6-week, single-blind, active run-in phase in which all potential participants receive metformin. Only patients tolerating metformin by taking at least 80% of allocated medication will enter the trial and be randomised to 1500 mg of metformin XR or an identical placebo. The primary outcome is the proportion of AAA events defined as rupture-related mortality or need for surgical repair. Secondary outcomes include AAA growth, major adverse cardiovascular events and health-related quality of life. In order to test if metformin reduced the risk of AAA events by at least 25%, 616 primary outcome events will be required (power 90%, alpha 0.05).

Discussion

Currently, there is no drug therapy for AAA. Past trials have found no convincing evidence of the benefit of multiple blood pressure lowering, antibiotics, a mast cell inhibitor, an anti-platelet drug and a lipid-lowering medication on AAA growth. MAT is one of a number of trials now ongoing testing metformin for AAA. MAT, unlike these other trials, is designed to test the effect of metformin on AAA events. The international collaboration needed for MAT will be challenging to achieve given the current COVID-19 pandemic. If this challenge can be overcome, MAT will represent a trial unique within the AAA field in its large size and design.

Trial registration

Australian Clinical Trials ACTRN12618001707257. Registered on 16 October 2018

Management of High Cardiovascular Risk in Diabetic Patients: Focus on Low Density Lipoprotein Cholesterol and Appropriate Drug Use in General Practice

This study aimed to evaluate the management of high cardiovascular risk (CVr) in the patients with diabetes by exploring the prescribing behavior in a setting of general practitioners (GPs). A retrospective cohort study was carried out using the data recorded between 2018 and 2020 in the clinical database of 10 GPs. Diabetes was defined using the International Classification of Diseases (ICD-9-CM) coding (250*) or using the laboratory parameters (hyperglycemia condition: ≥126 mg/dL). A cohort was described stratifying by demographic, clinical and therapeutic characteristics, and laboratory tests. Both the CVr and statin prescriptions were evaluated; adherence to statin therapy (medication possession ratio, MPR ≥ 80) was calculated in accordance with the low-density lipoprotein cholesterol (LDL-C) target. The multivariate logistic regression models with adjusted odds ratios (ORs) and the corresponding 95% Confidence Intervals (CIs) were calculated to identify the predictors of lipid modifying agents use and achieved target therapy; moreover, glucose-lowering drugs use was evaluated. Out of 13,206 people screened, 1,851 (14.0%) patients were affected by diabetes mellitus (DM), and 1,373 were identified at high/very high CVr. Of them, 1,158 (84.3%) had at least one measurement of LDL-C, and 808 (58.8%) received a prescription with at least one lipid-lowering drug (LLD). The patients at high/very high CVr treated or not treated with LLD, reached the LDL-C target in 24.0 and 10.3%, respectively (p < 0.001). Furthermore, 34.6% of patients treated with high intensity LLDs and adherent to therapy showed the LDL-C values below the therapeutic target. Out of 1,373 patients at high/very high CVr, 958 (69.8%) had at least one prescription of glucose-lowering drugs. Of them, 52.0% (n = 498) were prescribed not in agreement with the current guidelines. More specifically, 392 patients (40.9%) were treated with metformin only, while the remaining 106 (11.1%) were treated with metformin together with hypoglycemic agents other than glucagon-like peptide-1 receptor agonists (GLP1-RA) or sodium-glucose-transporter 2 (SGLT2) inhibitors. Our results suggest the urgent need to improve the management of patients with diabetes at high and very high CVr in the real life, to reduce the burden of diabetes on the health system.

Kidney Disease Management in the Hospital Setting: A Focus on Inappropriate Drug Prescriptions in Older Patients

Aging with multimorbidity and polytherapy are the most significant factors that could led to inappropriate prescribing of contraindicated medications in patients with chronic kidney disease (CKD). The aim of this study was to evaluate the prescriptions of contraindicated drugs in older adults in CKD and to identify their associated factors in a hospital context. An observational retrospective study was carried out considering all patients ≥65 years with at least one serum creatinine value recorded into the REPOSI register into 2010-2016 period. The estimated glomerular filtration rate (eGFR) was applied to identify CKD. A descriptive analysis was performed to compare demographic and clinical characteristics; logistic regression models were used to estimate factors of inappropriate and percentage changes of drug use during hospitalization. A total of 4,713 hospitalized patients were recorded, of which 49.8% had an eGFR <60 ml/min/1.73 m2; the 21.9% were in treatment with at least one inappropriate drug at the time of hospital admission with a decrease of 3.0% at discharge (p = 0.010). The probability of using at least one contraindicated drug was significantly higher in patients treated with more several drugs (OR 1.21, 95% CI 1.16-1.25, p <0.001) and with CKD end-stages (G4: 16.90, 11.38-25.12, p < 0.001; G5: 19.38, 11.51-32.64, p < 0.001). Low-dose acetylsalicylic acid was the contraindicated drug mainly used at the time of admission, reducing 1.2% at discharge. An overall increase in therapeutic appropriateness in hospitalized older patients with CKD was observed, despite a small percentage of therapeutic inappropriateness at discharge that underlines the need for a closer collaboration with the pharmacologist to improve the drug management.

Global Epidemiology, Health Outcomes, and Treatment Options for Patients With Type 2 Diabetes and Kidney Failure

The burden of type 2 diabetes and related complications has steadily increased over the last few decades and is one of the foremost global public health threats in the 21st century. Diabetes is one of the leading causes of chronic kidney disease and kidney failure and is an important contributor to the cardiovascular morbidity and mortality in this population. In addition, up to one in three patients who have received kidney transplants develop post-transplant diabetes, but the management of this common complication continues to pose a significant challenge for clinicians. In this review, we will describe the global prevalence and temporal trend of kidney failure attributed to diabetes mellitus in both developing and developed countries. We will examine the survival differences between treated kidney failure patients with and without type 2 diabetes, focusing on the survival differences in those on maintenance dialysis or have received kidney transplants. With the increased availability of novel hypoglycemic agents, we will address the potential impacts of these novel agents in patients with diabetes and kidney failure and in those who have developed post-transplant diabetes.

Development and validation of explicit criteria to identify potentially inappropriate prescribing for adults with type 2 diabetes mellitus

BACKGROUND

Early detection and timely resolution of potentially inappropriate prescribing (PIP) prevents adverse outcomes and improves patient care. An explicit tool specifically designed to detect PIP among people with Type 2 Diabetes Mellitus (T2DM) has not been published.

OBJECTIVES

This study aims to develop and validate the Inappropriate Medication Prescribing Assessment Criteria for Type 2 Diabetes Mellitus (IMPACT2DM); an explicit tool that can be used to identify PIP for adults with T2DM.

METHODS

Current national and international guidelines for the management of T2DM and drug information software programs were used to generate potential items. The content of the IMPACT2DM was validated by 2 consecutive rounds of Delphi method. Physicians and clinical pharmacists experienced in providing care for people with diabetes and authors of selected diabetes guidelines were invited to participate in the Delphi panel. Consensus was assumed if 90% (first round) and 85% (second round) of expert panelists showed agreement to include or exclude an item.

RESULTS

A total of 95 potential items were generated from selected diabetes guidelines and drug information software programs. After the first Delphi round 27 items had ≥90% agreement and were included in the tool; 19 items were considered not PIP and were excluded from the tool. The second round contained 49 items; of these 43 were included and 6 were excluded from the tool. The final IMPACT2DM contains 70 items categorized by type of PIP and arranged in terms of medical conditions and medication classes. IMPACT2DM can be applied using information on medical charts and requires minimal or no clinical knowledge to assess quality of diabetes care and improve medication selection.

CONCLUSIONS

IMPACT2DM has been developed from current quality evidence and undergone content validation. It is the first explicit tool specifically designed to identify PIP for adults with T2DM.

Metformin Use Is Associated with Fewer Complications in Patients with Type-2 Diabetes Undergoing Total Knee Arthroplasty: A Propensity Score-Matched Analysis

BACKGROUND

Diabetes is a well-established risk factor for complications following total knee arthroplasty (TKA), and the incidence of type-2 diabetes is increasing. Metformin is considered first-line therapy for type-2 diabetes and has been shown to reduce all-cause mortality and to possess anti-inflammatory properties. The impact of metformin use as it relates to outcomes following TKA is unknown. The purpose of this study was to investigate this relationship.

METHODS

This is a retrospective cohort study using the Truven MarketScan database. Adult patients undergoing unilateral, primary TKA were identified. We included only patients with a preoperative diagnosis of type-2 diabetes and established 2 cohorts based on metformin status. Propensity score matching was performed to match patients who used metformin to those who did not (1-to-1). Patients were matched on factors including age, sex, insulin status, other diabetic medications, comorbidities, complexity of diabetes, and smoking status. Regression analysis was then performed on matched cohorts to examine 90-day outcomes. A subgroup analysis was performed on 1-year revision rates.

RESULTS

After matching, there were 32,186 patients in both the metformin group and the no-metformin group, resulting in a total of 64,372 included patients. Baseline characteristics were similar between groups. Regression analysis, performed on matched cohorts, demonstrated that the no-metformin group had increased odds of readmission (odds ratio [OR], 1.09 [95% confidence interval (CI), 1.04 to 1.15]; p < 0.001), emergency department presentation (OR, 1.09 [95% CI, 1.04 to 1.14]; p < 0.001), extended length of stay (OR, 1.12 [95% CI, 1.06 to 1.15]; p < 0.001), periprosthetic joint infection (OR, 1.30 [95% CI, 1.13 to 1.50]; p < 0.001), deep vein thrombosis (OR, 1.17 [95% CI, 1.09 to 1.26]; p < 0.001), acute kidney injury (OR, 1.21 [95% CI, 1.09 to 1.33]; p < 0.001), hypoglycemic events (OR, 1.25 [95% CI, 1.01 to 1.54]; p = 0.039), and 1-year revision (OR, 1.16 [95% CI, 1.01 to 1.33]; p = 0.033).

CONCLUSIONS

Metformin use in patients with type-2 diabetes undergoing TKA appears to be associated with lower odds of multiple complications and resource utilization parameters, including periprosthetic joint infection and 1-year revision rates. Given the frequency with which TKA is performed in patients with type-2 diabetes, this knowledge has the potential to improve optimization protocols and outcomes in this group of patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Different Effects of Metformin and A769662 on Sodium Iodate-Induced Cytotoxicity in Retinal Pigment Epithelial Cells: Distinct Actions on Mitochondrial Fission and Respiration

Oxidative stress-associated retinal pigment epithelium (RPE) cell death is critically implicated in the pathogenesis of visual dysfunction and blindness of retinal degenerative diseases. Sodium iodate (NaIO₃) is an oxidative retinotoxin and causes RPE damage. Previously, we found that NaIO₃ can induce human ARPE-19 cell death via inducing mitochondrial fission and mitochondrial dysfunction. Although metformin has been demonstrated to benefit several diseases possibly via AMP-activated protein kinase (AMPK) activation, it remains unknown how AMPK affects retinopathy in NaIO₃ model. Therefore, in this study, we compared the effects of metformin and AMPK activator A769662 on NaIO₃-induced cellular stress and toxicity. We found that A769662 can protect cells against NaIO₃-induced cytotoxicity, while metformin exerts an enhancement in cell death. The mitochondrial reactive oxygen species (ROS) production as well as mitochondrial membrane potential loss induced by NaIO₃ were not altered by both agents. In addition, NaIO₃-induced cytosolic ROS production, possibly from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and counteracting cell death, was not altered by A769662 and metformin. Notably, NaIO₃-induced mitochondrial fission and inhibition of mitochondrial respiration for ATP turnover were reversed by A769662 but not by metformin. In agreement with the changes on mitochondrial morphology, the ERK-Akt signal axis dependent Drp-1 phosphorylation at S616 (an index of mitochondrial fission) under NaIO₃ treatment was blocked by A769662, but not by metformin. In summary, NaIO₃-induced cell death in ARPE cells primarily comes from mitochondrial dysfunction due to dramatic fission and inhibition of mitochondrial respiration. AMPK activation can exert a protection by restoring mitochondrial respiration and inhibition of ERK/Akt/Drp-1 phosphorylation, leading to a reduction in mitochondrial fission. However, inhibition of respiratory complex I by metformin might deteriorate mitochondrial dysfunction and cell death under NaIO₃ stress.

Structural characterization, hypoglycemic effects and antidiabetic mechanism of a novel polysaccharides from Polygonatum kingianum Coll. et Hemsl

The rhizome of Polygonatum kingianum has been used as a traditional medicine in China. In this study, a novel polysaccharides (PKPs-1) was isolated from P. kingianum and characterized by its molecular weight, primary structure. The hypoglycemic activity of PKPs-1was investigated by in vitro assay with the HepG2 cell line and in vivo test using STZ-induced diabetic mice. Results showed that the average molecular weight of PKPs-1 was 14.05 kDa and is composed mainly of glucose and mannose. Methylation analysis indicated that this polysaccharides fraction consisted mainly of β1,2-link glucose. Besides, PKPs-1 exhibited significant anti-hyperglycemic activity on STZ-induced mice, improved insulin tolerance, and affected the metabolism of serum lipids. Results of real-time quantitative PCR (RT-PCR) showed that PKPs-1 significantly increased the expression of insulin receptor substrate-1 (IRS-1), phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT), indicating that PKPs-1 regulates glucose metabolism by activating the PI3K/AKT signaling pathway. This study provides new insights for investigating the hypoglycemic effects of PKPs-1 and suggests that PKPs-1 could be a promising functional food or medicine for treating T2DM.

The Impact of Genetic Polymorphisms in Organic Cation Transporters on Renal Drug Disposition

A considerable number of drugs and/or their metabolites are excreted by the kidneys through glomerular filtration and active renal tubule secretion via transporter proteins. Uptake transporters in the proximal tubule are part of the solute carrier (SLC) superfamily, and include the organic cation transporters (OCTs). Several studies have shown that specific genetic polymorphisms in OCTs alter drug disposition and may lead to nephrotoxicity. Multiple single nucleotide polymorphisms (SNPs) have been reported for the OCT genes (SLC22A1, SLC22A2 and SLC22A3), which can influence the proteins’ structure and expression levels and affect their transport function. A gain-in-function mutation may lead to accumulation of drugs in renal proximal tubule cells, eventually leading to nephrotoxicity. This review illustrates the impact of genetic polymorphisms in OCTs on renal drug disposition and kidney injury, the clinical significances and how to personalize therapies to minimize the risk of drug toxicity.

Chronic Kidney Disease Management in General Practice: A Focus on Inappropriate Drugs Prescriptions

Nephrotoxic drugs prescriptions are often prescribed inappropriately by general practitioners (GPs), increasing the risk of chronic kidney disease (CKD). The aim of this study was to detect inappropriate prescriptions in patients with CKD and to identify their predictive factors. A retrospective study on patients with creatinine values recorded in the period 2014-2016 followed by 10 GPs was performed. The estimated glomerular filtration rate (eGFR) was used to identify CKD patients. The demographic and clinical characteristics and drugs prescriptions were collected. A descriptive analysis was conducted to compare the characteristics and logistic regression models to estimate the predictive factors of inappropriate prescriptions. Of 4098 patients with creatinine values recorded, 21.9% had an eGFR <60 mL/min/1.73m². Further, 56.8% received inappropriate prescriptions, with a significantly lower probability in subjects with at least a nephrologist visit (Adj OR 0.54 (95% CI 0.36-0.81)) and a greater probability in patients treated with more active substances (1.10 (1.08-1.12)), affected by more comorbidities (1.14 (1.06-1.230)), or with serious CKD (G4/G5 21.28 (7.36-61.57)). Nonsteroidal anti-inflammatory drugs (NSAIDs) were the most used contraindicated drugs (48.5%), while acetylsalicylic acid was the most inappropriately prescribed (39.5%). Our results highlight the inappropriate prescriptions for CKD authorized by GPs and underline the need of strategies to improve prescribing patterns.

An investigation of the effects of metformin on ovarian ischemia-reperfusion injury in rats

Damage to the ovaries or tissue torsion can significantly reduce the ovarian reserve and thus cause severe gynecological and hormonal deficiencies. The discovery of new agents is always needed in the treatment of this condition. Metformin (MET) has been shown to be beneficial in attenuating ovarian ischemia-reperfusion injury. Fifty-six female Sprague Dawley rats were divided into seven groups. Group 1 represented the control group (C), Group 2, the ischemia group (I), and Group 3, the ischemia/reperfusion group (I/R). Group 4, the ischemia (I)+250 group, and Group 5, the ischemia (I)+500 group, received 250 mg/kg and 500 mg/kg MET, respectively. Group 6, the ischemia/reperfusion (I/R)+250 group, and Group 7, the ischemia/reperfusion (I/R)+500 group, received 250 mg/kg and 500 mg/kg MET, respectively. Tissue malondialdehyde (MDA), glutathione (GSH), and tumor necrosis factor-alpha (TNF-α) levels in ovarian tissue increased following I/R, while estradiol (E₂) levels decreased. Moreover, infiltration and diffuse edematous areas were observed in addition to diffuse vascular congestion and hemorrhage findings. Caspase-3 and nuclear factor kappa B (NF-κβ) expression levels also increased. MDA and TNF-α concentrations decreased in the MET treatment groups, while GSH and E₂ levels increased. The findings showed that I/R causes ovarian damage through the induction of oxidative stress, inflammation, and apoptosis. However, MET application was effective in preventing damage in ovarian tissue by reducing levels of reactive oxygen species, proinflammatory cytokines, caspase-3 and NF-κβ.