London School of Hygiene & Tropical Medicine

The slight increase in risk of developing type 2 diabetes while on statins could be the result of lowered cholesterol rather than as a direct effect of the drug, according to a new study published in JAMA Cardiology. 

Conducted by UCL and the University of Oxford, and funded by the British Heart Foundation, the research explored the effects of two types of cholesterol - low density lipoprotein (LDL) and high-density lipoprotein (HDL) -  as well as triglycerides, a dietary fat, on a person's predisposition to heart disease and diabetes. The study found that people with genes which cause them to have lower levels of LDL had less of a risk of developing heart disease. It also showed that those genetically linked to high LDL and HDL levels had a slightly decreased risk from developing type 2 diabetes.

Statins help lower cholesterol levels and this latest research could explain why previous studies have linked statin usage to diabetes.  The authors stated that the current guidelines on clinical statin usage should not change as the benefits of statins vastly outweigh the small increase in possibly developing diabetes.

Should the current advice on statin usage change? Is there now a need to monitor the risk of developing diabetes for patients using the drug? Liam Smeeth, Professor of Clinical Epidemiology at the School, explains:

"This is an interesting study that uses genetic variation in new ways to tell us about the relationship between cholesterol and diabetes.

"The study suggests that genetic factors that increase cholesterol are also associated with a lower risk of diabetes. The finding is consistent with the known small increased risk of diabetes among people taking statins. This increased risk of diabetes is greatly outweighed by the beneficial effects of statins on preventing heart attacks and strokes.

"The study does suggest that as new drugs are developed to reduce cholesterol, we will need to carefully assess them for any effect on diabetes."

Related links

• Statins controversy linked to rise in UK patients stopping the treatment
• Side effects of statins investigated in new £1m trial