Researchers have described a new mechanism of how statins, the widely used cholesterol-lowering drugs, may cause insulin resistance and diabetes1.

Statins work by inhibiting cholesterol biosynthesis in the body but a side effect of this class of drugs has also been reported – that of increasing the propensity for inducing insulin resistance and diabetes in patients.

Using a prototype statin (simvastatin), the researchers differentiated L6 muscle cells in culture to figure out how the drug may cause insulin resistance. They first showed that the effect of simvastatin was unrelated to its cholesterol biosynthesis inhibition property. Instead simvastatin had an effect on blocking insulin signalling in cells, thereby blocking glucose uptake.

On exploring how simvastatin blocks insulin signalling, the researchers found that treating cells with simvastatin increased fatty acid (fat) accumulation within the cells thus impairing insulin signalling.

Since millions of patients are chronic users of statins and these drugs are considered life saving for cardiovascular diseases, understanding this mechanism may help design new strategies to prevent this effect.