Metformin-associated risk of acute dialysis in patients with type 2 diabetes: A nationwide cohort study

Within and post-trial effects of an intensive lifestyle intervention on kidney disease in adults with overweight or obesity and type 2 diabetes mellitus: a secondary analysis of the Look AHEAD clinical trial

INTRODUCTION

The Look AHEAD randomized clinical trial reported that an 8-year intensive lifestyle intervention (ILI) compared with diabetes support and education (DSE) in adults aged 45-76 years with type 2 diabetes and overweight/obesity delayed kidney disease progression. Here, we report long-term post-intervention follow-up for the trial's secondary outcome of kidney disease.

RESEARCH DESIGN AND METHODS

We examined effects of ILI (n=2570) versus DSE (n=2575) on decline in estimated glomerular filtration rate (eGFR) to <45 mL/min/1.73 m2 or need for kidney replacement therapy (KRT: dialysis or kidney transplant) during intervention and post-intervention follow-up (median 15.6 years overall).

RESULTS

Incidence of eGFR <45 mL/min/1.73 m2 was lower in ILI during the intervention (HR=0.80, 95% CI=0.66 to 0.98) but not post-intervention (HR=1.03, 0.86 to 1.23) or overall (HR=0.92, 0.80 to 1.04). There were no significant treatment group differences in KRT. In prespecified subgroup analyses, age×treatment interactions were significant over total follow-up: p=0.001 for eGFR <45 mL/min/1.73 m2 and p=0.01 for KRT. The 2205 participants aged >60 years at baseline had benefit in both kidney outcomes during intervention and overall (HR=0.75, 0.62 to 0.90 for eGFR <45 mL/min/1.73 m2; HR=0.62, 0.43 to 0.91 for KRT). The absolute treatment effects were greater post-intervention: ILI reduced the rate of eGFR <45 mL/min/1.73 m2 by 0.46 and 0.76 cases/100 person-years during and post-intervention, respectively; and reduced KRT by 0.15 and 0.21 cases/100 person-years. The younger participants experienced no such post-intervention benefits.

CONCLUSIONS

ILI reduced kidney disease progression during and following the active intervention in persons aged ≥60 years. ILI should be considered for reducing kidney disease incidence in older persons with type 2 diabetes.

Effects of metformin and intensive lifestyle interventions on the incidence of kidney disease in adults in the DPP/DPPOS

AIMS

We analyzed the incidence of kidney disease in the Diabetes Prevention Program Outcomes Study (DPPOS) by originally randomized treatment group assignment: Intensive Lifestyle (ILS), Metformin (MET) or Placebo (PLB).

METHODS

The current analyses used a time-to-event approach in which the primary outcome was kidney disease, ascertained as urine albumin-to-creatinine ratio (ACR) ≥ 3.39 mg/mmol (30 mg/g) or eGFR <45 mL/min/1.73m2, with confirmation required at the next visit, or adjudicated end-stage kidney disease (ESKD).

RESULTS

At a median of 21 years following randomization in DPP, diabetes development was reduced in both the ILS (HR 0.73 [95%CI = 0.62, 0.85]) and MET groups (HR 0.85 [0.73, 0.99]) compared to the PLB group. Although risk for developing the primary kidney disease outcome was higher among those with incident diabetes compared to those without (HR 1.81 [1.43, 2.30]), it did not differ by intervention groups (ILS vs. PLB 1.02 (0.81, 1.29); MET vs. PLB 1.08 (0.86, 1.35). There was a non-significant metformin by age interaction (p = 0.057), with metformin being beneficial for kidney disease in the younger but potentially harmful in the older participants.

CONCLUSIONS

Development of kidney disease was increased in participants who developed diabetes but did not differ by original treatment group assignment.

CLINICAL TRIAL REGISTRATIONS

Diabetes Prevention Program (DPP) Clinical trial reg. no. NCT00004992 DPP Outcomes Study (DPPOS) Clinical trial reg. no. NCT0038727.

The Effectiveness and Safety of Metformin Compared to Sulfonylureas in Diabetic Nephropathy: A Systematic Review

Metformin and sulphonylureas are the most commonly used first-line anti-diabetic agents. However, medical practice guidelines and clinical experience caution against using these drugs in severe diabetic kidney disease. Consequently, the choice of anti-diabetic medicine in various stages of diabetic nephropathy should balance the benefits and risks to the patient. We aim to synthesize available evidence on the effectiveness and safety of metformin concerning sulfonylureas in patients with diabetic renal disease. The COSMOS-E (Guidance on conducting systematic reviews and meta-analyses of observational studies of etiology) and MOOSE (Meta-Analyses and Systematic Reviews of Observational Studies in Epidemiology) guidelines were followed when designing the systematic review. The present study assessed the effectiveness of metformin and sulphonylurea monotherapy regarding renal function. Studies published from 2001 to 2022 were included. We have identified 570 records from PubMed, BioMed Central, LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde), ScienceDirect, and PLoS (The Public Library of Science) Medicine databases. Eight cohort studies met the inclusion criteria. All studies reported adjusted hazard ratios with confidence limits. Metformin was found to be more effective in the following events: all-cause mortality, GFR (glomerular filtration rate), ESRD (end-stage renal disease) or death events, one-year risk of death or end-stage renal disease, cardiovascular events, heart failure hospitalization, and hypoglycemic episodes. However, metformin was less effective in acute renal replacement therapy, end-stage renal disease, and/or death, with a one-year risk of acute dialysis. Lactic acidosis was not significant with metformin. The present study recommends that metformin therapy is safe compared to sulfonylurea therapy in diabetic nephropathy patients, provided that the contraindications given in the guidelines are strictly adhered to.

Safety and effectiveness of metformin in patients with reduced renal function: A systematic review

AIM

To examine clinical and safety outcomes associated with metformin use in patients with impaired renal function.

MATERIALS AND METHODS

We searched PubMed and Embase databases from inception to August 2020, supplementing our search with a review of investigator files and reference lists of included studies. Any study reporting original data on metformin and patient-centred outcomes in patients with impaired renal function, defined as an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73m² , was included. Post hoc meta-analysis was performed for the outcomes of mortality, cardiovascular events and acidosis.

RESULTS

Nine small prospective studies enrolling patients with significantly impaired renal function identified only one case of clinically apparent lactic acidosis. Among 13 larger retrospective studies, seven examined the risk of mortality across patient subgroups; meta-analysis showed reductions in overall mortality at an eGFR of 45 mL/min/1.73m² or higher but not at an eGFR of less than 45 mL/min/1.73m² . Eight retrospective studies evaluated acidosis as an outcome; meta-analysis showed no increase in risk of acidosis except at an eGFR of less than 30 mL/min/1.73m² , in which group the HR was 1.97 (95% CI 1.03-3.77).

CONCLUSIONS

The literature shows metformin to be associated with reduced mortality and no increased risk of acidosis at an eGFR of 45 mL/min/1.73m² or higher. Metformin appears to be associated with fewer benefits and possible increases in the risk of acidosis at an eGFR of less than 30 mL/min/1.73m² . Consistent with US Food and Drug Administration guidelines, metformin should not be used at an eGFR less than 30 mL/min/1.73m² , and further research on its risk-benefit profile at eGFR values approaching 30 mL/min/1.73m² is warranted.

Mechanism and application of metformin in kidney diseases: An update

Metformin is an oral antihyperglycemic drug widely used to treat type 2 diabetes mellitus (T2DM), acting via indirect activation of 5' Adenosine monophosphate-activated Protein Kinase (AMPK). Beyond the anti-diabetic effect, accumulative pieces of evidence have revealed that metformin also everts a beneficial effect in diverse kidney diseases. In various acute kidney diseases (AKI) animal models, metformin protects renal tubular cells from inflammation, apoptosis, reactive oxygen stress (ROS), endoplasmic reticulum (ER) stress, epithelial-mesenchymal transition (EMT) via AMPK activation. In diabetic kidney disease (DKD), metformin also alleviates podocyte loss, mesangial cells apoptosis, and tubular cells senescence through AMPK-mediated signaling pathways. Besides, metformin inhibits cystic fibrosis transmembrane conductance regulator (CFTR)-mediated fluids secretion and the mammalian target of rapamycin (mTOR)-involved cyst formation negatively regulated by AMPK in autosomal dominant polycystic kidney disease (APDKD). Furthermore, metformin also contributes to the alleviation of urolithiasis and renal cell carcinoma (RCC). As the common pathway for chronic kidney disease (CKD) progressing towards end-stage renal disease (ESRD), renal fibrosis is ameliorated by metformin, to a great extent dependent on AMPK activation. However, clinical data are not always consistent with preclinical data, some clinical investigations showed the unmeaningful even detrimental effect of metformin on T2DM patients with kidney diseases. Most importantly, metformin-associated lactic acidosis (MALA) is a vital issue restricting the application of metformin. Thus, we conclude the application of metformin in kidney diseases and uncover the underlying molecular mechanisms in this review.

Is metformin associated with acute kidney injury? A case-control study of patients with type 2 diabetes admitted with acute infection

INTRODUCTION

Despite the long-term renoprotective effects of Metformin, a recent study on data from the U.S. Food and Drug Administration reported a possible nephrotoxic effect, contributing to the development of acute kidney injury (AKI). We investigated the association between metformin and AKI in patients admitted with the AKI-prone condition of acute infection and compared results with corresponding results of other antidiabetics.

METHODS

In a nationwide register-based case-control study, we identified Danish patients with type 2 diabetes hospitalized with acute infection between 2008 and 2018. Cases of AKI had an increase in plasma creatinine ≥  × 1.5 during admission, controls did not. Antidiabetics were identified up to 6 months before admission. Odds ratio (OR) of each antidiabetic was computed in separate multiple logistic regression models adjusted for relevant medication and comorbidities and results compared.

RESULTS

We included 46,811 patients, hereof 9454 AKIs (20%) and 2186 (4.7%) severe AKIs. Overall, 56% were males, median age (IQR) was 73 (65-81). Sixty percent received metformin, 13% sulfonylurea, 31% insulin and 8% dipeptidyl peptidase-4 inhibitors (DPP-4i), with equal distribution between cases and controls. Metformin was associated with increased OR (CI) for AKI, 1.07 (1.02-1.12), equally to sulfonylurea, 1.10 (1.03-1.18) and DPP-4i, 1.11 (1.02-1.20), but not insulin, 0.99 (0.93-1.05). In severe AKI, results for metformin were 1.27 (1.25-1.40) but increased equivalently to other antidiabetics.

CONCLUSIONS

In patients with type 2 diabetes hospitalized with acute infection, metformin was not independently associated with AKI, since other antidiabetics were also significantly associated, indicating confounding by indication.

Association of Metformin Use With End-Stage Renal Disease in Patients With Type 2 Diabetes Mellitus: A Nationwide Cohort Study Under the Pay-for-Performance Program

Animal studies have demonstrated that metformin exerts a renoprotective effect. Human studies of patients with diabetes mellitus (DM) regarding the association of metformin use with end-stage renal disease (ESRD) are lacking. Patients with type 2 DM and without a history of kidney disease who were enrolled under the pay-for-performance program of the National Health Insurance in Taiwan were identified. Those who received ≥90 cumulative defined daily doses of metformin within 1 year were selected (metformin users) and compared with a 1:1 propensity score-matched metformin nonuser cohort. Primary and secondary outcomes were development of ESRD and chronic kidney disease (CKD), respectively. Independent predictors were investigated using Cox regression analysis. A total of 24 158 pairs of metformin users and nonusers were enrolled, with an incidence of ESRD of 1908 and 1723 and CKD of 1095 and 1056 cases per 100 000 person-years, respectively. Metformin use was independently associated with increased risks of ESRD (adjusted hazard ratio, 1.22; 95% confidence interval, 1.12-1.32) and CKD (adjusted hazard ratio, 1.25; 95% confidence interval, 1.12-1.40) in a dose-response relationship. Patients with hypertension plus nonuse of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers potentiated kidney damage by metformin. In patients with DM, use of metformin may increase the risk of ESRD and CKD. Health care professionals should be alert and closely monitor renal function when prescribing metformin.

Metformin use and cardiovascular events in patients with type 2 diabetes and chronic kidney disease

AIMS

Metformin could have benefits on cardiovascular disease and kidney disease progression but is often withheld from individuals with diabetes and chronic kidney disease (CKD) because of a concern that it may increase the risk of lactic acidosis.

MATERIALS AND METHODS

All-cause mortality, cardiovascular death, cardiovascular events (death, hospitalization for heart failure, myocardial infarction, stroke or myocardial ischemia), end stage renal disease (ESRD) and the kidney disease composite (ESRD or death) were compared in metformin users and non-users with diabetes and CKD enrolled in the Trial to Reduce Cardiovascular Events with Aranesp (darbepoeitin-alfa) Therapy (TREAT) (NCT00093015). Outcomes were compared after propensity matching of users and non-users and in multivariable proportional hazards models.

RESULTS

There were 591 individuals who used metformin at baseline and 3447 non-users. Among propensity-matched users, the crude incidence rate for mortality, cardiovascular mortality, cardiovascular events and the combined endpoint was lower in metformin users than in non-users, but ESRD was marginally higher (4.0% vs 3.6%). Metformin use was independently associated with a reduced risk of all-cause mortality (HR, 0.49; 95% CI, 0.36-0.69), cardiovascular death (HR, 0.49; 95% CI, 0.32-0.74), the cardiovascular composite (HR, 0.67, 95% CI, 0.51-0.88) and the kidney disease composite (HR, 0.77; 95% CI, 0.61-0.98). Associations with ESRD (HR, 1.01; 95% CI, 0.65-1.55) were not significant. Results were qualitatively similar in adjusted analyses of the full population. Two cases of lactic acidosis were observed.

CONCLUSIONS

Metformin may be safer for use in CKD than previously considered and may lower the risk of death and cardiovascular events in individuals with stage 3 CKD.

A systematic review comparing the evidence for kidney function outcomes between oral antidiabetic drugs for type 2 diabetes

Background: The development of kidney disease is a serious complication among people with type 2 diabetes mellitus, associated with substantially increased morbidity and mortality.  We aimed to summarise the current evidence for the relationship between treatments for type 2 diabetes and long-term kidney outcomes, by conducting a systematic search and review of relevant studies. Methods: We searched Medline, Embase and Web of Science, between 1st January 1980 and 15th May 2018 for published clinical trials and observational studies comparing two or more classes of oral therapy for type 2 diabetes. We included people receiving oral antidiabetic drugs. Studies were eligible that; (i) compared two or more classes of oral therapy for type 2 diabetes; (ii) reported kidney outcomes as primary or secondary outcomes; (iii) included more than 100 participants; and (iv) followed up participants for 48 weeks or more. Kidney-related outcome measures included were Incidence of chronic kidney disease, reduced eGFR, increased creatinine, 'micro' and 'macro' albuminuria. Results: We identified 15 eligible studies, seven of which were randomised controlled trials and eight were observational studies. Reporting of specific renal outcomes varied widely. Due to variability of comparisons and outcomes meta-analysis was not possible. The majority of comparisons between treatment with metformin or sulfonylurea indicated that metformin was associated with better renal outcomes. Little evidence was available for recently introduced treatments or commonly prescribed combination therapies. Conclusions: Comparative evidence for the effect of treatments for type 2 diabetes on renal outcomes, either as monotherapy or in combination is sparse.

Age modifies the risk factor profiles for acute kidney injury among recently diagnosed type 2 diabetic patients: a population-based study

The incidence of acute kidney injury (AKI) rises with age and is associated with multiple risk factors. Here, we compared the risk factors for AKI between younger and older incident diabetic patients to examine the trends in risk alteration for individual factors across different age groups. Between 2007 and 2013, we selected all incident type 2 diabetic adults from the Taiwan National Health Insurance registry, stratified based on age: young (< 65 years), old (≥ 65 but < 75 years), and older-old (≥ 75 years). All factors with potential renal influence (e.g., comorbidities, medications, and diagnostics/procedures) were recorded during the study period, with a nested case-controlled approach utilized to identify independent risk factors for AKI in each age group. Totally, 930,709 type 2 diabetic patients were categorized as young (68.7%), old (17.7%), or older-old (13.6%). Older-old patients showed a significantly higher incidence of AKI than the old and the young groups. Cardiovascular morbidities (hypertension, atrial fibrillation, acute coronary syndrome, and cerebrovascular disease) were shown to increase the risk of AKI, although the risk declined with increasing age. Chronic obstructive pulmonary disease and receiving cardiac catheterization elevated the risk of AKI preferentially in the older-old/old and older-old group, respectively, while the administration of angiotensin-converting enzyme/α-blocker and angiotensin receptor blocker/calcium channel blocker reduced the risk of AKI preferentially in the older-old and older-old/old group, respectively. In conclusion, our findings highlight the importance of devising age-specific risk factor panels for AKI in patients with recently diagnosed type 2 diabetes.