Purpose of review
We provide an overview of recent publications that extend clinically relevant knowledge relating to metformin's effects on lipids and atherosclerotic vascular disease and/or provide insights into the drug's mechanisms of action on the heart and vasculature.
We focus on original research in humans or in human tissues. Several recently completed randomized clinical trials have reported effects of metformin on surrogate measures of atherosclerotic vascular disease, including carotid–intima media thickness, vascular reactivity and calcification in people with Type 1 (T1D) and Type 2 (T2D) diabetes as well as nondiabetic dysglycaemia. In addition, observational studies have provided novel insights into the mechanisms of metformin's effects on carotid plaque, monocytes/macrophages, vascular smooth muscle and endothelial cells, including via 5’-adenosine monophosphate-activated protein kinase (AMPK) activation.
Recent trials based on surrogate outcome measures have provided further data suggesting protective effects of metformin against vascular disease in youth and adults with Type 1 diabetes, as well as in adults with prediabetes and Type 2 diabetes. In parallel, human tissue and cell studies have provided new insights into pleiotropic effects of metformin and suggest novel drug targets. As metformin is an inexpensive agent with an established safety profile, larger scale clinical trials based on hard clinical outcomes [cardiovascular disease (CVD) events] are now indicated.