Metformin, one of the most widely used medications for type 2 diabetes, has a positive effect on LDL cholesterol as well as blood glucose, according to research published in Diabetes Care
on 5 August 2015.
People with type 2 diabetes are at increased risk of heart attack and stroke, and managing their cholesterol levels, particularly the more harmful LDL cholesterol, is an important part of their treatment.
“Controlling cholesterol is very important for all types of diabetes. Getting cholesterol under control can help to reduce the risk of terrible complications such as heart disease, stroke and blindness,” says Douglas Twenefour, clinical advisor at Diabetes UK.
Metformin was first described in scientific literature in 1922 and has been used to treat type 2 diabetes since the 1950s by lowering glucose levels and improving insulin sensitivity. Analysis of data from the UKPDS 34 study
showed that intensive therapy with metformin significantly reduces diabetes-related end points and deaths, and a meta-analysis of clinical trials found that the drug could also significantly lower total and LDL cholesterol levels
. However, its mechanism of action on blood lipids is still not understood.
To try to find out more about how a single drug can have an impact on two completely different aspects of the disease, the researchers pulled data on metformin-treated patients with type 2 diabetes who were not using insulin from the Cooperative Health Research in the Region of Augsburg (KORA) cohort. This was a large-scale population-based cohort followed between 1999 and 2001, and the researchers analysed the genetic and metabolomic profiles of the patients.
The team found that patients with type 2 diabetes treated with metformin had lower levels of three cholesterol metabolites along with lower LDL cholesterol levels. The findings pointed to metformin working via the AMP-activated protein kinase pathway, and will help to learn more about the drug. However, they don’t provide enough evidence for prescribing metformin to manage cholesterol, according to Twenefour.
“The study’s findings are interesting and add to what we know about the benefits of metformin and the mechanisms by which it takes effect, but further research, including results from major clinical trials, will be needed to conclusively show that metformin could be used directly to protect people from CVD — such trials are underway at present,” adds Twenefour.
 Genuth S, Eastman R, Kahn R et al. Implications of the United Kingdom prospective diabetes study. Diabetes Care 2003;26(1):S28-32.
 Wulffele MG, Kooy A, De Zeeuw D et al. The effect of metformin on blood pressure, plasma cholesterol and triglycerides in type 2 diabetes mellitus: a systematic review. J Intern Med 2004;256(1):1–14.