Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

Site-Specifically Launched Microneedles for the Combined Treatment of Psoriasis-Diabetic Comorbidity

Psoriasis and diabetes are both common comorbidities for each other, where inflammation and insulin resistance act in a vicious cycle, driving the progression of disease through the activation of the NF-κB signaling pathway. Therefore, disrupting the linkage between inflammation and insulin resistance by inhibiting the NF-κB pathway presents a promising therapeutic strategy for addressing psoriasis-diabetic comorbidity. Herein, an open-loop therapy was developed by integrating microneedle-mediated short- and long-range missiles to target psoriasis and diabetes, respectively. The short-range missile (curcumin nanoparticle) could be stationed in the psoriatic skin for topical and prolonged antipsoriasis therapy, while the long-range missile (metformin) is capable of penetrating transdermal barriers to induce a systemic hypoglycemic effect. More attractively, the short- and long-range missiles could join hands to inhibit the NF-κB signaling pathway and diminish inflammation, effectively disrupting the crosstalk between inflammation and insulin resistance. Pharmacodynamic studies showed that this microneedle-mediated combination, possessing dual anti-inflammatory and antihyperglycemic properties, proves to be highly efficacious in alleviating typical symptoms and inflammatory response in both nondiabetic and diabetic mice with imiquimod (IMQ)-induced psoriasis models. Hence, the microneedle-mediated open-loop therapy shows great potential in the management of psoriasis-diabetes comorbidity.

Protective effect of heat-processed Gynostemma pentaphyllum on high fat diet-induced glucose metabolic disorders mice

Glucose metabolic disorders (GMD) can promote insulin resistance (IR) and diabetes, and damage liver and kidney. Gynostemma pentaphyllum is commonly used in the clinical treatment of diabetes, but the research on its main active constituents and GMD has not been reported yet. This study explores the therapeutic potential of gypenosides of heat-processed Gynostemma pentaphyllum (HGyp) on high-fat diet-induced GMD in mice. HGyp was administered at different doses for 12 weeks. The investigation encompassed an array of parameters, including body weight, blood lipids, blood glucose, and liver tissue components. Metabolomic and network analyses were conducted to uncover potential targets and pathways associated with HGyp treatment. The results revealed that HGyp alleviated GMD by reducing body weight, blood glucose, and improving blood lipids levels, while increasing liver glycogen and antioxidant enzyme levels. Additionally, HGyp exhibited protective effects on liver and kidney health by reducing tissue damage. Fourteen blood components were detected by LC-MS. Metabolomic and network analyses indicated the potential engagement of the AGE-RAGE signaling pathway in the therapeutic effects of HGyp.Furthermore, Western blot and ELISA assays confirmed that HGyp upregulated GLO1 and GLUT4 while down-regulating AGEs and RAGE expression in liver tissue. In light of these findings, HGyp demonstrates promise as a potential therapeutic candidate for combating GMD, warranting further exploration in the development of therapeutic strategies or functional products.

A Comparative Study of Acidosis in Diabetic Advanced Chronic Kidney Disease Patients on and off Metformin

Aim

The aim of the study is to assess the risk of acidosis in diabetic advanced chronic kidney disease (CKD) patients on and off metformin.

Methods

This retrospective descriptive study was conducted in the nephrology department in The Kidney Centre Post Graduate Training Institute (TKC PGTI) Karachi from February to April 2020. We reviewed the records of all patients over 18 years old who visited the nephrology outpatient department in three months in 2020 (from February 2020 to April 2020), who had CKD (stage 2-5), are not on dialysis, and had type 2 diabetes. These were divided into two groups: those on metformin for more than one year and those not on metformin. We looked at hospitalizations due to acidosis in the previous one-year period.

Results

A total of 524 CKD patients had diabetes; out of those, 268 patients were on metformin, and 256 were not on metformin. The male vs. female distribution was 52.1% vs. 47.9%. A total of 114 (21.8%) patients required admission in the previous one-year period, and only 12 hospitalized patients had acidosis, seven (58.3%) were on metformin, and five (41.7%) were not on metformin, which was statistically insignificant.

Conclusion

Biguanides, especially metformin, is a known oral hypoglycemic drug used for decades to treat type 2 diabetes mellitus (DM). Metformin use is related to a rare but serious adverse event, metformin-associated lactic acidosis (MALA), especially in renal failure patients. In our study, metformin use in CKD diabetic patients did not result in more admissions due to acidosis than non-metformin users.

Advantages of the use of metformin in patients with impaired uric acid metabolism

Metformin is one of the oldest and at the same time relevant and effective drugs for the treatment of type 2 diabetes. At the same time, the mechanism of the hypoglycemic effect was not completely clear until recently. Current data suggest that the mechanism of action of metformin contributes to the development of an anti-inflammatory effect, as well as a decrease in the level of uric acid, and its use can be potentially useful in patients with hyperuricemia and gout.

Metformin slows liver cyst formation and fibrosis in experimental model of polycystic liver disease

Polycystic liver disease (PLD) is a hereditary liver disease in which the number of cysts increases over time, causing various abdominal symptoms and poor quality of life. Although effective treatment for PLD has not been established, we recently reported that long-term exercise ameliorated liver cyst formation and fibrosis with the activation of AMP-activated protein kinase (AMPK) in polycystic kidney (PCK) rats, a PLD model. Therefore, the aim of this study was to investigate whether metformin, an indirect AMPK activator, was effective in PCK rats. PCK rats were randomly divided into a control (Con) group and a metformin-treated (Met) group. The Met group was treated orally with metformin in drinking water. After 12 wk, liver function, histology, and signaling cascades of PLD were examined in the groups. Metformin did not affect the body weight or liver weight, but it reduced liver cyst formation, cholangiocyte proliferation, and fibrosis around the cyst. Metformin increased the phosphorylation of AMPK and tuberous sclerosis complex 2 and decreased the phosphorylation of mammalian target of rapamycin, S6, and extracellular signal-regulated kinase and the expression of cystic fibrosis transmembrane conductance regulator, aquaporin I, transforming growth factor-β, and type 1 collagen without changes in apoptosis or collagen degradation factors in the liver. Metformin slows the development of cyst formation and fibrosis with the activation of AMPK and inhibition of signaling cascades responsible for cellular proliferation and fibrosis in the liver of PCK rats.NEW & NOTEWORTHY This study indicates that metformin, an indirect AMPK activator slows liver cyst formation and fibrosis in PLD rat model. Metformin attenuates excessive cell proliferation in the liver with the inactivation of mTOR and ERK pathways. Metformin also reduces the expression of proteins responsible for cystic fluid secretion and liver fibrosis. Metformin and AMPK activators may be potent drugs for polycystic liver disease.

Is the use of metformin in patients undergoing dialysis hazardous for life? A systematic review of the safety of metformin in patients undergoing dialysis

AIMS

Metformin may have clinical benefits in dialysis patients; however, its safety in this population is unknown. This systematic review evaluated the safety of metformin in dialysis patients.

METHODS

MEDLINE, Embase, CENTRAL, PsycINFO and the Cochrane Library were searched for randomised controlled trials and observational studies evaluating metformin use in dialysis patients. Three authors reviewed the studies and extracted data. The primary outcomes were mortality, occurrence of lactic acidosis and myocardial infarction (MI) in patients taking metformin during dialysis treatment for ≥12 months (long term). Risk of bias was assessed using Risk Of Bias In Nonrandomised Studies of Interventions (ROBINS-1). Overall quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Fifteen observational studies were eligible; 7 were prospective observational studies and 8 were case reports/case series. No randomised controlled trials were identified. The 7 prospective observational studies (n = 194) reported on cautious metformin use in patients undergoing maintenance dialysis. Only 3 provided long-term follow-up data. In 2 long-term studies of metformin therapy (≤1000 mg/d) in patients undergoing peritoneal dialysis (PD), 1 reported 6 deaths (6/83; 7%) due to major cardiovascular events (3 MI) and the other reported no deaths (0/35). One long-term study of metformin therapy (250 mg to 500 mg thrice weekly) in patients undergoing haemodialysis reported 4 deaths (4/61; 7%) due to major cardiovascular events (2 MI). These findings provide very low-quality evidence as they come from small observational studies.

CONCLUSION

The evidence regarding the safety of metformin in people undergoing dialysis is inconclusive. Appropriately designed randomised controlled trials are needed to resolve this uncertainty.

Role of metformin in treatment of patients with chronic obstructive pulmonary disease: a systematic review

Chronic obstructive pulmonary disease (COPD) is commonly associated with type 2 diabetes mellitus (T2DM). Metformin is a first-line treatment for most patients with T2DM, and may have antiaging, antioxidant, and anti-tumour effects. A few published studies report the use of metformin for the treatment of COPD in patients with or without T2DM, but the results are inconsistent. This study aimed to confirm the effectiveness and safety of metformin as a treatment option in patients with COPD. We performed a systematic search of PubMed, EMBASE, and the Cochrane database from their starting date to December 2017. Randomised controlled trials (RCTs), controlled clinical trials, and retrospective researches reporting the use of metformin for treating patients with COPD were identified. We included a total of six articles (involving 3,467 participants) and found that metformin may benefit patients with COPD and T2DM by improving health status and symptoms, hospitalisations, and mortality. There was no effect on patients with COPD without T2DM. Metformin causes minimal increases in plasma lactate concentrations without lactic acidosis and has little impact on blood glucose and minor adverse events. Metformin is safe and effective for treating COPD in patients with concomitant T2DM.

Not quite type 1 or type 2, what now? Review of monogenic, mitochondrial, and syndromic diabetes

Diabetes mellitus is a heterogeneous group of conditions defined by resultant chronic hyperglycemia. Given the increasing prevalence of diabetes mellitus and the increasing understanding of genetic etiologies, we present a broad review of rare genetic forms of diabetes that have differing diagnostic and/or treatment implications from type 1 and type 2 diabetes. Advances in understanding the genotype-phenotype associations in these rare forms of diabetes offer clinically available examples of evolving precision medicine where defining the correct genetic etiology can radically alter treatment approaches. In this review, we focus on forms of monogenic diabetes, mitochondrial diabetes, and syndromic diabetes.

Metformin-Associated Lactic Acidosis Undergoing Renal Replacement Therapy in Intensive Care Units: A Five-Million Population-Based Study in the North-West of Italy

BACKGROUND

Metformin-associated lactic acidosis (MALA) is a severe complication of drug administration with significant morbidity and mortality. So far no study in large population areas have examined the incidence, clinical profile and outcome of acute kidney injury (AKI)-MALA patients admitted in intensive care units (ICUs) and treated by renal replacement therapy (MALA-RRT).

METHODS

Retrospective analysis over a 6-year period (2010-2015) in Piedmont and Aosta Valley regions (5,305,940 inhabitants, 141,174 diabetics treated with metformin) of all MALA-RRT cases.

RESULTS

One hundred and seventeen cases of AKI-MALA-RRT were observed (12.04/100,000 metformin treated diabetics, 1.45% of all RRT-ICU patients). Survival rate was 78.3%. The average duration of RRT was 4.0 days at mean dialysis effluent of 977 mL/kg/day. At admission most patients were dehydrated, and experienced shock and oliguria.

CONCLUSION

Our data showed that MALA-RRT is a common complication, needing more prevention. Adopted policy of early, extended, continuous and high efficiency dialysis could contribute to an observed high survival rate. Video Journal Club "Cappuccino with Claudio Ronco" at http://www.karger.com/?doi=471917.

Could metformin be used in patients with diabetes and advanced chronic kidney disease?

Diabetes is an important cause of end stage renal failure worldwide. As renal impairment progresses, managing hyperglycaemia can prove increasingly challenging, as many medications are contra-indicated in moderate to severe renal impairment. Whilst evidence for tight glycaemic control reducing progression to renal failure in patients with established renal disease is limited, poor glycaemic control is not desirable, and is likely to lead to progressive complications. Metformin is a first-line therapy in patients with Type 2 diabetes, as it appears to be effective in reducing diabetes related end points and mortality in overweight patients. Cessation of metformin in patients with progressive renal disease may not only lead to deterioration in glucose control, but also to loss of protection from cardiovascular disease in a cohort of patients at particularly high risk. We advocate the need for further study to determine the role of metformin in patients with severe renal disease (chronic kidney disease stage 4-5), as well as patients on dialysis, or pre-/peri-renal transplantation. We explore possible roles of metformin in these circumstances, and suggest potential key areas for further study.

Update on the treatment of type 2 diabetes mellitus

To achieve good metabolic control in diabetes and keep long term, a combination of changes in lifestyle and pharmacological treatment is necessary. Achieving near-normal glycated hemoglobin significantly, decreases risk of macrovascular and microvascular complications. At present there are different treatments, both oral and injectable, available for the treatment of type 2 diabetes mellitus (T2DM). Treatment algorithms designed to reduce the development or progression of the complications of diabetes emphasizes the need for good glycaemic control. The aim of this review is to perform an update on the benefits and limitations of different drugs, both current and future, for the treatment of T2DM. Initial intervention should focus on lifestyle changes. Moreover, changes in lifestyle have proven to be beneficial, but for many patients is a complication keep long term. Physicians should be familiar with the different types of existing drugs for the treatment of diabetes and select the most effective, safe and better tolerated by patients. Metformin remains the first choice of treatment for most patients. Other alternative or second-line treatment options should be individualized depending on the characteristics of each patient. This article reviews the treatments available for patients with T2DM, with an emphasis on agents introduced within the last decade.

Toxicity of Oral Agents Used to Treat Diabetes

Oral agents used for the management of type 2 diabetes mellitus include sulfonylureas, biguanides, thiazolidinediones, metglitinides, and/or α -glucosidase inhibitors. These medication classes can be further classified as hypoglycemic and antihyperglycemic agents. Hypoglycemia is a major symptom of toxicity of these agents, particularly with the sulfonylureas, including combination medications that include sulfonylureas. In overdose situations, metformin, a biguanide, can lead to considerable gastrointestinal adverse effects and potentially lactic acidosis in severe cases. Data on the management of toxicities of the other classes are limited. This article will review the treatment modalities that have been used for treating symptomatic hypoglycemia and metformin-induced lactic acidosis.

Retrospective analysis of lactic acidosis-related parameters upon and after metformin discontinuation in patients with diabetes and chronic kidney disease

PURPOSE

To investigate association between renal functions, lactic acid levels and acid-base balance in type 2 diabetes patients with chronic kidney disease under metformin treatment and after metformin discontinuation in a real-life setting.

METHODS

A total of 65 patients with diabetes (mean age 68.5 ± 8.9 years, 56.9 % females) in whom metformin treatment was discontinued due to reduced glomerular filtration rate (GFR) were included in this retrospective study. Data on patient demographics, metformin treatment and laboratory findings on the last day of metformin treatment and 2-3 weeks after metformin discontinuation including blood lactate and creatinine, estimated glomerular filtration rate (eGFR) and acid-base balance measurements in blood [pH, bicarbonate, base excess] were collected from medical records. The correlation of lactate levels with eGFR, blood pH and creatinine levels and changes in laboratory findings after metformin discontinuation were evaluated.

RESULTS

Before metformin discontinuation, hyperlactatemia was observed in 78.5 % of patients and metabolic acidosis in 36.9 % of patients, but none had lactic acidosis. Patients with normolactatemia and hyperlactatemia were similar in terms of metformin dosage and laboratory parameters. Lactate levels were not significantly correlated with serum creatinine (r = -0.14; p = 0.263) and eGFR (r = 0.11, p = 0.374). After metformin discontinuation, a significant decrease was observed in median lactate levels (from 2.20 to 1.85 mmol/L; p = 0.002).

CONCLUSION

In conclusion, our findings support the low risk of MALA among patients with mild-to-moderate renal impairment and the likelihood of metformin to be an innocent bystander without a pathogenic role in the lactic acidosis in most cases.

Noninsulin Antidiabetic Drugs for Patients with Type 2 Diabetes Mellitus: Are We Respecting Their Contraindications?

AIM

To assess prescribing practices of noninsulin antidiabetic drugs (NIADs) in T2DM with several major contraindications according to prescribing information or clinical guidelines: renal failure, heart failure, liver dysfunction, or history of bladder cancer.

METHODS

Cross-sectional, descriptive, multicenter study. Electronic medical records were retrieved from all T2DM subjects who attended primary care centers pertaining to the Catalan Health Institute in Catalonia in 2013 and were pharmacologically treated with any NIAD alone or in combination.

RESULTS

Records were retrieved from a total of 255,499 pharmacologically treated patients. 78% of patients with some degree of renal impairment (glomerular filtration rate (GFR) < 60 mL/min) were treated with metformin and 31.2% with sulfonylureas. Even in the event of severe renal failure (GFR < 30 mL/min), 35.3% and 22.5% of patients were on metformin or sulfonylureas, respectively. Moreover, metformin was prescribed to more than 60% of patients with moderate or severe heart failure.

CONCLUSION

Some NIADs, and in particular metformin, were frequently used in patients at high risk of complications when they were contraindicated. There is a need to increase awareness of potential inappropriate prescribing and to monitor the quality of prescribing patterns in order to help physicians and policymakers to yield better clinical outcomes in T2DM.

Metformin in peritoneal dialysis: a pilot experience

OBJECTIVE

In a number of patients, the antidiabetic drug metformin has been associated with lactic acidosis. Despite the fact that diabetes mellitus is the most common cause of end-stage renal disease (ESRD) and that peritoneal dialysis (PD) is an expanding modality of treatment, little is known about optimal treatment strategies in the large group of PD patients with diabetes. In patients with ESRD, the use of metformin has been limited because of the perceived risk of lactic acidosis or severe hypoglycemia. However, metformin use is likely to be beneficial, and PD might itself be a safeguard against the alleged complications.

METHODS

Our study involved 35 patients with insulin-dependent type 2 diabetes [median age: 54 years; interquartile range (IQR): 47-59 years] on automated PD (APD) therapy. Patients with additional risk factors for lactic acidosis were excluded. Metformin was introduced at a daily dose in the range 0.5 - 1.0 g. All patients were monitored for glycemic control by blood sugar levels and HbA1c. Plasma lactic acid levels were measured weekly for 4 weeks and then monthly to the end of the study. Plasma and effluent metformin and plasma lactate levels were measured simultaneously.

RESULTS

In this cohort, the median duration of diabetes was 18 years (IQR: 14 - 21 years), median time on PD was 31 months (IQR: 27 - 36 months), and median HbA1c was 6.8% (IQR: 5.9% - 6.9%). At metformin introduction and at the end of the study, the median anion gap was 11 mmol/L (IQR: 9 - 16 mmol/L) and 12 mmol/L (IQR: 9 - 16 mmol/L; p > 0.05) respectively, median pH was 7.33 (IQR: 7.32 - 7.36) and 7.34 (IQR: 7.32 - 7.36, p > 0.05) respectively, and mean metformin concentration in plasma and peritoneal fluid was 2.57 ± 1.49 mg/L and 2.83 ± 1.7 mg/L respectively. In the group overall, mean lactate was 1.39 ± 0.61 mmol/L, and hyperlactemia (>2 mmol/L to 5 mmol/L) was found in 4 of 525 plasma samples (0.76%), but the patients presented no symptoms. None of the patients registered a plasma lactate level above 5 mmol/L. We observed no correlation between plasma metformin and plasma lactate (r = 0.27).

CONCLUSIONS

Metformin may be used with caution in APD patients with insulin-dependent type 2 diabetes. Although our study demonstrated the feasibility of metformin use in APD, it was not large enough to demonstrate safety; a large-scale study is needed.

Inpatient treatment of type 2 diabetes

BACKGROUND

Type 2 diabetes is common in hospitalized patients and is often accompanied by comorbidities; it is thus reasonable to ask whether the current standard treatments for type 2 diabetes are suitable for in-hospital use. We discuss the current glucose-lowering strategies and glycemic targets and derive practical recommendations for their application in hospitalized patients.

METHODS

The pertinent literature, including clinical trials, review articles, guidelines, and manufacturers' information is selectively reviewed.

RESULTS

In critically ill patients with diabetes, the glucose concentration target value should be 140 to 180 mg/dL. In stable patients, the target should be less than 140 mg/dL in the fasting state and less than 180 mg/dL after meals. Hypoglycemic episodes should be strictly avoided. Temporary treatment with insulin is indicated for most hospitalized patients with diabetes, although oral antidiabetic agents may be continued if the hospitalization is expected to be brief. Intravenous insulin is advisable in certain situations, e.g., long operations or metabolic decompensation. Glucose-lowering strategies must be chosen individually for each patient, with consideration of the relevant comorbidities (e.g. coronary heart disease, congestive heart failure, cirrhosis, renal failure) and special conditions (e.g. prolonged fasting, administration of contrast agents, high-dose glucocorticoid treatment).

CONCLUSION

The treatment of patients with type 2 diabetes in the hospital is very different from their treatment at home. The particular conditions and comorbidities that can arise in the hospital necessitate flexible, individualized strategies for lowering blood glucose concentration.

Metformin-associated acute kidney injury and lactic acidosis

Objectives. Metformin is the preferred oral antidiabetic agent for type 2 diabetes. Lactic acidosis is described as a rare complication, usually during an acute kidney injury (AKI). Material and Methods. We conducted a prospective observational study of metformin-associated AKI cases during four years. 29 cases were identified. Previous renal function, clinical data, and outcomes were recorded. Results. An episode of acute gastroenteritis precipitated the event in 26 cases. Three developed a septic shock. Three patients died, the only related factor being liver dysfunction. More severe metabolic acidosis hyperkalemia and anemia were associated with higher probabilities of RRT requirement. We could not find any relationship between previous renal dysfunction and the outcome of the AKI. Conclusions. AKI associated to an episode of volume depletion due to gastrointestinal losses is a serious complication in type 2 diabetic patients on metformin. Previous renal dysfunction (mild-to-moderate CKD) has no influence on the severity or outcome.

Use of Metformin in Patients with Kidney and Cardiovascular Diseases

Metformin is an insulin-sensitizing agent with anti-hyperglycemic properties that is widely used for the treatment of type-2 diabetes. The efficacy of metformin in reducing hyperglycemia is well established, and there is emerging evidence that its chronic use is associated with cancer and cardiovascular disease (CVD) risk reduction. While the hypoglycemic properties of metformin are largely attributed to suppression of hepatic glucose production and increases in peripheral tissue insulin sensitivity, the precise mechanism of the hypoglycemic action of metformin remains unclear. There is evidence that metformin use interrupts mitochondrial oxidative stress in the liver and corrects abnormalities of intracellular calcium metabolism in insulin-sensitive tissues (liver, skeletal muscle, and adipocytes) and cardiovascular tissue. However, the use of metformin in patients with kidney disease, a high-risk CVD state, is confounded by confusion regarding appropriate concerns about the development of lactic acidosis in this population. Thus, we will review current evidence on metformin use for improving CVD outcomes and its therapeutic use in kidney disease.

Role of metformin in the management of polycystic ovary syndrome

Polycystic ovary syndrome is the most common endocrinological disorder affecting 4-12% of women and also the most controversial. Metformin was logically introduced to establish the extent to which hyperinsulinaemia influences the pathogenesis of the condition. Early studies were very encouraging. Randomized controlled studies and several metaanalyses have changed the picture and put the drug that was once heralded as magic in a much contracted place. More work is needed to establish its right place in particular with regards to the prevention of many gestational and long-term complications.

The use of metformin in type 1 diabetes: a systematic review of efficacy

AIMS/HYPOTHESIS

As adding metformin to insulin therapy has been advocated in type 1 diabetes, we conducted a systematic review of published clinical trials and clinical trial databases to assess the effects on HbA(1c), weight, insulin-dose requirement and adverse effects.

METHODS

We constructed evidence tables and fitted a fixed-effects model (inverse variance method) in order to assess heterogeneity between studies and give a crude measure of each overall treatment effect.

RESULTS

Of 197 studies identified, nine involved randomisation with informed consent of patients with type 1 diabetes to metformin (vs placebo or comparator) in either a parallel or crossover design for at least 1 week. We noted marked heterogeneity in study design, drug dose, age of participants and length of follow-up. Metformin was associated with reductions in: (1) insulin-dose requirement (5.7-10.1 U/day in six of seven studies); (2) HbA(1c) (0.6-0.9% in four of seven studies); (3) weight (1.7-6.0 kg in three of six studies); and (4) total cholesterol (0.3-0.41 mmol/l in three of seven studies). Metformin was well tolerated, albeit with a trend towards increased hypoglycaemia. Formal estimates of combined effects from the five trials which reported appropriate data indicated a significant reduction in insulin dose (6.6 U/day, p < 0.001) but no significant reduction in HbA(1c) (absolute reduction 0.11%, p = 0.42). No reported trials included cardiovascular outcomes.

CONCLUSIONS/INTERPRETATION

Metformin reduces insulin-dose requirement in type 1 diabetes but it is unclear whether this is sustained beyond 1 year and whether there are benefits for cardiovascular and other key clinical outcomes.

[GRADE: from grading the evidence to developing recommendations. A description of the system and a proposal regarding the transferability of the results of clinical research to clinical practice]

The Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group represents an international collaboration of guideline developers, clinicians, health services researchers and methodologists. Many leading organizations, including the World Health Organization (WHO), use the GRADE approach because it has led to progress in the assessment of evidence and in the development of healthcare recommendations. The GRADE system distinguishes the quality of evidence from the strength of a recommendation. The quality of evidence reflects the extent of confidence that an estimate of effect is correct if it is used in the context of single endpoints. In the context of giving guidance, it reflects the extent to which confidence in an estimate of the effect is adequate to support recommendations. The strength of a recommendation, separated into strong and weak or conditional recommendations for or against an intervention, is defined as the extent to which one can be confident that the desirable effects of an intervention outweigh the undesirable effects. A recommendation for action requires consideration for the magnitude of the expected benefit and downsides of an intervention for all patient-important endpoints, the associate values and preferences and resource use. The GRADE system includes a systematic approach to evaluate the generalizability of study results to healthcare practice. Judgments about generalizability, better termed directness, are separated into judgments about the availability of direct comparisons between two alternative management strategies and judgments about differences between the population, intervention, comparator to the intervention, and outcomes (PICO) of interest for a given question, and those included in the relevant studies. In addition to providing an overview of the GRADE system, this article focuses on the approach to assessing directness or generalizability.

[Integrative assessment of evidence in healthcare: the GRADE system]

Decisions are a double-edged sword: they always and inevitably come with positive and negative consequences. Decisions in healthcare--from a systems level to the individual patient--are not different. This approach acknowledges that for all recommendations and decisions all the important consequences need to be considered. Along these lines, one must evaluate the certainty that estimates of effects and decisions are likely to be correct. Thus, as institutions, professional societies, organisations and individuals, we should follow approaches focusing on systematic and integrative assessment of available best evidence. Longstanding and broad experience with the development of recommendations, including systematically developed guidelines, led a group of methodologists, health officers, clinicians and guideline developers to form the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group. The GRADE approach differentiates the assessment of the quality of evidence from the strength of a recommendation in healthcare. For a step-by-step evaluation of the quality of evidence, one must consider all patient relevant endpoints. It is common that many relevant and acceptable studies provide evidence for single outcomes. Therefore, integrating summaries and assessments beyond meta-analyses are required. The explicit and transparent description of the single steps in these assessments and the consideration of all currently known criteria for the assessment of the quality of evidence are among the most important advantages and innovations of the GRADE system and are described here briefly. The overall quality of evidence of all outcomes that are critical for decision-making are summarized on the basis of the lowest quality of evidence. If, for example, the evidence for six of seven critical outcomes is of low quality while moderate quality evidence is available for the other critical outcome, the overall quality of evidence is considered low to avoid a false sense of certainty with the assessment of the evidence for a given topic. A recommendation according to GRADE also requires a considerate judgement about the magnitude of the expected balance of benefits and downsides for the important outcomes, the relative values and preferences associated with these outcomes and considerations about the required resources. The international collaboration and acceptance by many organisations is an indicator of GRADE's innovative nature and advances in the assessment of evidence and development of recommendations in the context of healthcare.

Metformin, sulfonylureas, or other antidiabetes drugs and the risk of lactic acidosis or hypoglycemia: a nested case-control analysis

OBJECTIVE

Lactic acidosis has been associated with use of metformin. Hypoglycemia is a major concern using sulfonylureas. The aim of this study was to compare the risk of lactic acidosis and hypoglycemia among patients with type 2 diabetes using oral antidiabetes drugs.

RESEARCH DESIGN AND METHODS

This study is a nested case-control analysis using the U.K.-based General Practice Research Database to identify patients with type 2 diabetes who used oral antidiabetes drugs. Within the study population, all incident cases of lactic acidosis and hypoglycemia were identified, and hypoglycemia case subjects were matched to up to four control patients based on age, sex, practice, and calendar time.

RESULTS

Among the study population of 50,048 type 2 diabetic subjects, six cases of lactic acidosis during current use of oral antidiabetes drugs were identified, yielding a crude incidence rate of 3.3 cases per 100,000 person-years among metformin users and 4.8 cases per 100,000 person-years among users of sulfonylureas. Relevant comorbidities known as risk factors for lactic acidosis could be identified in all case subjects. A total of 2,025 case subjects with hypoglycemia and 7,278 matched control subjects were identified. Use of sulfonylureas was associated with a materially elevated risk of hypoglycemia. The adjusted odds ratio for current use of sulfonylureas was 2.79 (95% CI 2.23-3.50) compared with current metformin use.

CONCLUSIONS

Lactic acidosis during current use of oral antidiabetes drugs was very rare and was associated with concurrent comorbidity. Hypoglycemic episodes were substantially more common among sulfonylurea users than among users of metformin.

Rosiglitazone for type 2 diabetes mellitus

BACKGROUND

Diabetes has long been recognised as a strong, independent risk factor for cardiovascular disease, a problem which accounts for approximately 70% of all mortality in people with diabetes. Prospective studies show that compared to their non-diabetic counterparts, the relative risk of cardiovascular mortality for men with diabetes is two to three and for women with diabetes is three to four. The two biggest trials in type 2 diabetes, the United Kingdom Prospective Diabetes Study (UKPDS) and the University Group Diabetes Program (UGDP) study did not reveal a reduction of cardiovascular endpoints through improved metabolic control. Theoretical benefits of the peroxisome proliferator activated receptor gamma (PPAR-gamma) activator rosiglitazone on endothelial function and cardiovascular risk factors might result in fewer macrovascular disease events in people with type 2 diabetes mellitus.

OBJECTIVES

To assess the effects of rosiglitazone in the treatment of type 2 diabetes.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE and The Cochrane Library.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials in adult people with type 2 diabetes mellitus and had a trial duration of at least 24 weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Pooling of studies by means of fixed-effects meta-analysis could be performed for adverse events only.

MAIN RESULTS

Eighteen trials which randomised 3888 people to rosiglitazone treatment were identified. Longest duration of therapy was four years with a median of 26 weeks. Published studies of at least 24 weeks rosiglitazone treatment in people with type 2 diabetes mellitus did not provide evidence that patient-oriented outcomes like mortality, morbidity, adverse effects, costs and health-related quality of life are positively influenced by this compound. Metabolic control measured by glycosylated haemoglobin A1c (HbA1c) as a surrogate endpoint did not demonstrate clinically relevant differences to other oral antidiabetic drugs. Occurrence of oedema was significantly raised (OR 2.27, 95% confidence interval (CI) 1.83 to 2.81). The single large RCT (ADOPT - A Diabetes Outcomes Progression Trial) indicated increased cardiovascular risk. New data on raised fracture rates in women reveal extensive action of rosiglitazone in various body tissues.

AUTHORS' CONCLUSIONS

New studies should focus on patient-oriented outcomes to clarify the benefit-risk ratio of rosiglitazone therapy. Safety data and adverse events of all investigations (published and unpublished) should be made available to the public.

Diabetes Care for Patients with Peripheral Arterial Disease

The number of diabetics will increase almost 70% in developed countries during the next 20 years: peripheral arterial disease is a common and costly complication. The incidence of cardiovascular disease (mortality and morbidity) due to atherosclerosis, is higher among patients with diabetes than in those without diabetes. Intensive management of diabetes, including glycaemic control, treatment of hypertension and dyslipidemia, as well as nonpharmacological interventions, decreases both micro- and macrovascular complications. Aspirin and clopidogrel have less antiplatelet effect in patients with diabetes. Metformin therapy is considered a risk factor for lactic acidosis if not withdrawn 2 days before angiography, but this risk is extremely low in patients with normal renal function. Peri-operative hyperglycaemia and large fluctuations in plasma glucose increase postoperative mortality and morbidity and careful measures are required to minimise these effects.

Diabetes mellitus and anesthesia

Diabetes mellitus is an extremely common condition with specific associated comorbidity. Its incidence is rising. Diabetic patients have more perioperative complications than nondiabetic patients. These complications may be related to the presence of organ damage secondary to the diabetes, rather than the defects in carbohydrate metabolism themselves, or to perioperative hyperglycemia. Several new drugs are available for the treatment of diabetes, and these are associated with specific and significant side effects, and varying lengths of action with which the anesthetist should be familiar. Few data are available regarding recommendations for fasting in the presence of these newer drugs. In the postoperative period and during cardiac surgery, hyperglycemia has been shown to be detrimental, and should probably be sought and managed aggressively. The incidence of intraoperative hyperglycemia in noncardiac surgery patients is not as well-defined, nor are the effects of aggressive management.

Pioglitazone for type 2 diabetes mellitus

BACKGROUND

Diabetes has long been recognised as a strong, independent risk factor for cardiovascular disease, a problem which accounts for approximately 70% of all mortality in people with diabetes. Prospective studies show that compared to their non-diabetic counterparts, the relative risk of cardiovascular mortality for men with diabetes is two to three and for women with diabetes is three to four. The two biggest trials in type 2 diabetes, the United Kingdom Prospective Diabetes Study (UKPDS) and the University Group Diabetes Program (UGDP) study did not reveal a reduction of cardiovascular endpoints through improved metabolic control. Theoretical benefits of the newer peroxisome proliferator activated receptor gamma (PPAR-gamma) activators like pioglitazone on endothelial function and cardiovascular risk factors might result in fewer macrovascular disease events in people with type 2 diabetes mellitus.

OBJECTIVES

To assess the effects of pioglitazone in the treatment of type 2 diabetes.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE and The Cochrane Library. The last search was conducted in August 2006.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials in adult people with type 2 diabetes mellitus and had a trial duration of at least 24 weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Pooling of studies by means of random-effects meta-analysis could be performed for adverse events only.

MAIN RESULTS

Twenty-two trials which randomised approximately 6200 people to pioglitazone treatment were identified. Longest duration of therapy was 34.5 months. Published studies of at least 24 weeks pioglitazone treatment in people with type 2 diabetes mellitus did not provide convincing evidence that patient-oriented outcomes like mortality, morbidity, adverse effects, costs and health-related quality of life are positively influenced by this compound. Metabolic control measured by glycosylated haemoglobin A1c (HbA1c) as a surrogate endpoint did not demonstrate clinically relevant differences to other oral antidiabetic drugs. Occurrence of oedema was significantly raised. The results of the single trial with relevant clinical endpoints (Prospective Pioglitazone Clinical Trial In Macrovascular Events--PROactive study) have to be regarded as hypothesis-generating and need confirmation.

AUTHORS' CONCLUSIONS

Until new evidence becomes available, the benefit-risk ratio of pioglitazone remains unclear. Different therapeutic indications for pioglitazone of the two big U.S. and European drug agencies should be clarified to reduce uncertainties amongst patients and physicians.

Multiple cardiovascular considerations in a 76-year-old man

A 76-year-old man with a history of myocardial infarction, Type 2 diabetes, hypertension, hypercholesterolemia, and heart failure presents with muscle pain and spasm. A number of medication-related problems are identified by the pharmacist. Prioritization of medication-related problems and therapeutic recommendations are provided. The medication-related problems described in this case reinforce the need for establishing individualized action plans and avoiding making too many changes in medication regimens at one time. In addition, the issue of nonpharmacological causes of symptoms can be overlooked when focusing on medication-induced illness.

Fulminant lactic acidosis in two patients with Type 2 diabetes treated with metformin

Lactic acidosis is a known adverse risk of metformin treatment. We report two cases in whom fulminant lactic acidosis developed during treatment. There were no contraindications to metformin treatment and both were admitted with abdominal discomfort for some days, causing dehydration. Both patients had renal failure on admission, developed multiple organ failure and both suffered a massive stroke. One patient died and the other survived but is severely disabled. We suggest, in both cases, that acute renal failure developed as a result of dehydration, causing metformin accumulation and lactic acidosis. We recommend that all patients on metformin should consider discontinuation of metformin treatment in the event of a severe medical condition causing dehydration.

Improved clinical outcomes associated with metformin in patients with diabetes and heart failure

OBJECTIVE

Metformin is considered contraindicated in patients with heart failure because of concerns over lactic acidosis, despite increasing evidence of potential benefit. The aim of this study was to evaluate the association between metformin and clinical outcomes in patients with heart failure and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Using the Saskatchewan Health databases, 12,272 new users of oral antidiabetic agents were identified between the years 1991 and 1996. Subjects with incident heart failure (n = 1,833) were identified through administrative records based on ICD-9 code 428 and grouped according to antidiabetic therapy: metformin monotherapy (n = 208), sulfonylurea monotherapy (n = 773), or combination therapy (n = 852). Multivariate Cox proportional hazards models were used to assess differences in all-cause mortality, all-cause hospitalization, and the combination (i.e., all-cause hospitalization or mortality).

RESULTS

Average age of subjects was 72 years, 57% were male, and average follow-up was 2.5 +/- 2.0 (SD) years. Compared with sulfonylurea therapy, fewer deaths occurred in subjects receiving metformin: 404 (52%) for sulfonylurea monotherapy versus 69 (33%) for metformin monotherapy (hazard ratio [HR] 0.70 [95% CI 0.54-0.91]) and 263 (31%) for combination therapy (0.61 [0.52-0.72]). A reduction in deaths or hospitalizations was also observed: 658 (85%) for sulfonylurea monotherapy versus 160 (77%) for metformin monotherapy (0.83 [0.70-0.99]) and 681 (80%) for combination therapy (0.86 [0.77-0.96]). There was no difference in time to first hospitalization between study groups.

CONCLUSIONS

Metformin, alone or in combination, in subjects with heart failure and type 2 diabetes was associated with lower morbidity and mortality compared with sulfonylurea monotherapy.

Comparative outcomes study of metformin intervention versus conventional approach the COSMIC Approach Study

OBJECTIVE

Metformin was approved by the Food and Drug Administration in 1995 subject to the conduct of a randomized trial to evaluate the risk of lactic acidosis or other serious adverse events (SAEs) with this agent, under usual care conditions.

RESEARCH DESIGN AND METHODS

The Comparative Outcomes Study of Metformin Intervention versus Conventional (COSMIC) Approach Study was a randomized, open-label, active-comparator, parallel-group, 1-year trial in type 2 diabetic patients suboptimally controlled on diet or sulfonylurea. Patients received metformin (n = 7,227) or other usual care treatments (n = 1,505). The primary end point was the incidence of SAEs, death, and hospitalization.

RESULTS

SAEs occurred in 10.3% (95% CI 9.6-11.1%) of the metformin group and in 11.0% (9.5-12.7%) of the usual care group (P = 0.431). Lactic acidosis did not occur. All-cause mortality (1.1% [0.9-1.4%] vs. 1.3% [0.8-2.0%], P = 0.596) and hospitalization (9.4% [8.8-10.1%] vs. 10.4% [8.9-12.1%], P = 0.229) were similar between groups.

CONCLUSIONS

The incidence of SAEs was similar between groups. Lactic acidosis was not observed. Metformin may be safely prescribed for type 2 diabetes if contraindications and warnings are respected. This study demonstrates the utility of large, simple trials for risk evaluation of treatments for common diseases.

Initiating oral glucose-lowering therapy with metformin in tyape 2 diabetic patients: an evidence-based strategy to reduce the burden of late-developing diabetes complications

A major aim of glucose-lowering therapy in people with diabetes is to delay or prevent the late-developing complications of diabetes that threaten the quality and duration of life. While intensive interventions to control hyperglycaemia may impair well-being to some extent, the balance of quality of life is usually highly positive. Diet and exercise therapy remains the cornerstone of management, and should usually be given a trial alone first. However, the magnitude and duration of benefit from this intervention is insufficient for most people. More frequent, early, use of metformin is an evidence-based strategy for reducing the risk of adverse outcomes of diabetes in people with type 2 diabetes with sub-optimal glucose control on lifestyle measures alone. This has been recognised in recent evidenced-based guidelines from the UK National Institute for Clinical Excellence and from Diabetes UK, which now support the use of metformin as initial pharmacological therapy for all people without contraindications to the drug. Other national and local guideline committees should consider updating their recommendations on diabetes management in line with these findings.

[Oral diabetes treatment. Which substance is indicated at which time?]

The prevalence of type 2 diabetes continues to show a clear upward trend in Germany. In earlier days it was considered the "harmless diabetes of old age," but has become increasingly recognized as a disease carrying a high risk of vascular sequelae as well as shortening the diabetic's remaining life expectancy if adequate therapy is not initiated. In addition to correcting hyperglycemia, treatment consists in effective management of concomitant risk factors such as hypertension, dyslipidemia, and adiposity resulting from faulty nutrition and lack of exercise. In the large majority of overweight type 2 diabetics, metformin is the oral antidiabetic agent of first choice provided the patient does not exhibit renal insufficiency, which represents the most important contraindication. This recommendation for monotherapy of overweight type 2 diabetics is supported by an endpoint study. In contrast, no equivalent evidence is available on any of the possible options for oral combination therapy.

In-hospital management of type 2 diabetes mellitus

The increasing prevalence of type 2 diabetes brings with it a need to understand the particular impact of hospitalization in this patient population. Type 2 diabetes has been shown to increase length of stay, infection, and mortality rates. To optimize inpatient care, it is important to understand target glycemic goals as well as in-hospital glucose monitoring and diabetes management goals. A practical review of regimens for subcutaneous insulin administration,intravenous insulin infusion, and inpatient use of oral agents is presented. Methods for achieving adequate preparation and education of the patient and family for discharge to the outpatient setting are also discussed.