Metformin use in decompensated heart failure

Update on clinical and experimental management of diabetic cardiomyopathy: addressing current and future therapy

Diabetic cardiomyopathy (DCM) is a severe secondary complication of type 2 diabetes mellitus (T2DM) that is diagnosed as a heart disease occurring in the absence of any previous cardiovascular pathology in diabetic patients. Although it is still lacking an exact definition as it combines aspects of both pathologies - T2DM and heart failure, more evidence comes forward that declares DCM as one complex disease that should be treated separately. It is the ambiguous pathological phenotype, symptoms or biomarkers that makes DCM hard to diagnose and screen for its early onset. This re-view provides an updated look on the novel advances in DCM diagnosis and treatment in the experimental and clinical settings. Management of patients with DCM proposes a challenge by itself and we aim to help navigate and advice clinicians with early screening and pharmacotherapy of DCM.

A Rare Outcome Induced by Metformin Intoxication: Severe Lactic Acidosis and Hepatotoxicity

Metformin is a widely used oral anti-diabetic agent that decreases insulin resistance. Lactic acidosis rarely develops with this medication. Metformin-induced hepatotoxicity has been rarely reported in the literature. We describe a patient, who presented with lactic acidosis and hepatotoxicity after ingestion of 40 pills of metformin in order to commit suicide. The most important treatment step in patients with metformin-associated lactic acidosis (MALA) is high-volume hemodialysis and hemofiltration.

My Sweetheart Is Broken: Role of Glucose in Diabetic Cardiomyopathy

Despite overall reductions in heart disease prevalence, the risk of developing heart failure has remained 2-fold greater among people with diabetes. Growing evidence has supported that fluctuations in glucose level and uptake contribute to cardiovascular disease (CVD) by modifying proteins, DNA, and gene expression. In the case of glucose, clinical studies have shown that increased dietary sugars for healthy individuals or poor glycemic control in diabetic patients further increased CVD risk. Furthermore, even after decades of maintaining tight glycemic control, susceptibility to disease progression can persist following a period of poor glycemic control through a process termed "glycemic memory." In response to chronically elevated glucose levels, a number of studies have identified molecular targets of the glucose-mediated protein posttranslational modification by the addition of an O-linked N-acetylglucosamine to impair contractility, calcium sensitivity, and mitochondrial protein function. Additionally, elevated glucose contributes to dysfunction in coupling glycolysis to glucose oxidation, pentose phosphate pathway, and polyol pathway. Therefore, in the "sweetened" environment associated with hyperglycemia, there are a number of pathways contributing to increased susceptibly to "breaking" the heart of diabetics. In this review we will discuss the unique contribution of glucose to heart disease and recent advances in defining mechanisms of action.

Metformin revisited: a critical review of the benefit-risk balance in at-risk patients with type 2 diabetes

Metformin is unanimously considered a first-line glucose-lowering agent. Theoretically, however, it cannot be prescribed in a large proportion of patients with type 2 diabetes because of numerous contraindications that could lead to an increased risk of lactic acidosis. Various observational data from real-life have shown that many diabetic patients considered to be at risk still receive metformin and often without appropriate dose adjustment, yet apparently with no harm done and particularly no increased risk of lactic acidosis. More interestingly, recent data have suggested that type 2 diabetes patients considered at risk because of the presence of traditional contraindications may still derive benefit from metformin therapy with reductions in morbidity and mortality compared with other glucose-lowering agents, especially sulphonylureas. The present review analyzes the benefit-risk balance of metformin therapy in special populations, namely, patients with stable coronary artery disease, acute coronary syndrome or myocardial infarction, congestive heart failure, renal impairment or chronic kidney disease, hepatic dysfunction and chronic respiratory insufficiency, all conditions that could in theory increase the risk of lactic acidosis. Special attention is also paid to elderly patients with type 2 diabetes, a population that is growing rapidly, as older patients can accumulate several comorbidities classically considered contraindications to the use of metformin. A review of the recent scientific literature suggests that reassessment of the contraindications of metformin is now urgently needed to prevent physicians from prescribing the most popular glucose-lowering therapy in everyday clinical practice outside of the official recommendations.

Metformin and heart failure: never say never again

Metformin represents the cornerstone of treatment for type 2 diabetes mellitus. Traditionally, heart failure (HF) was considered a contraindication to its use. However, more recent evidence has shown that this should no longer be the case. Indeed, studies have demonstrated that metformin may even reduce the risk of incident HF and mortality in diabetic patients, while improving up to 2-year survival rates in those with HF. In addition, it appears to exert cardioprotective actions. Although longer follow-up data and more explicit information about the situation in patients with very advanced HF are needed, the cardiac safety of metformin has profound clinical implications and may be anticipated to further encourage its widespread use.