Statins: cardiovascular benefits outweigh diabetes risk

The benefits of taking statins to reduce the risk of cardiovascular disease outweigh the increased risk of developing diabetes experienced by some patients who take these cholesterol-lowering drugs, according to an Article published Online First in The Lancet.

A team of scientists led by Professor Paul Ridker, based at Brigham and Women’s Hospital, Boston, USA, analysed data gathered during JUPITER, the first controlled study to report that taking statins results in an increased risk of developing diabetes.  This finding, subsequently confirmed by several other studies, led to the US Food and Drug Administration (FDA) enforcing a compulsory warning on statin labels, advising users of the increased risk of diabetes.

Professor Ridker and colleagues analysed the JUPITER results to determine whether or not the risk of developing diabetes was outweighed by the benefits to cardiovascular health conferred on patients who took statins over the five year trial period.  They found marked differences in the likelihood of developing diabetes, depending on whether or not the patient was already at risk of developing diabetes when the trial began.

Patients who had at least one risk factor for diabetes were 28% more likely to develop diabetes when using statins, compared to patients in the control group.  However, there was no discernible increase in the risk of developing diabetes for patients who did not have any risk factors for diabetes.

Although the use of statins clearly increased the likelihood of developing diabetes in patients already at risk of the disease, these patients were still 39% less likely to develop cardiovascular illness while using statins, and 17% less likely to die over the trial period.  Patients who were not already at risk of developing diabetes experienced a 52% reduction in cardiovascular illness when taking statins, and had no increase in diabetes risk.

According to Professor Ridker, “Our results show that in participants with and without diabetes risk, the absolute benefits of statin therapy are greater than the hazards of developing diabetes.  We believe that most physicians and patients would regard heart attack, stroke and death to be more severe outcomes than the onset of diabetes, and so we hope that these results ease concern about the risks associated with statin therapy when these drugs are appropriately prescribed – in conjunction with improved diet, exercise and smoking cessation – to reduce patients’ risk of cardiovascular disease.”

In a linked Comment, Professor Gerald Watts of the University of Western Australia’s Cardiometabolic Research Centre, Royal Perth Hospital, suggests that if further work confirms the findings from the new Lancet study, the FDA may wish to consider restricting their warning about the increased risks of diabetes to people with existing major risk factors for the disease.

However, according to Professor Watts, “A major take-home message for the clinician involved in either primary or secondary prevention of cardiovascular disease is that all individuals on a statin who have major risk factors for diabetes, particularly impaired fasting glucose, need to be informed about the risk, monitored regularly for hyperglycaemia, and advised to lose weight and take regular physical exercise to mitigate the emergence of diabetes.”