Statins and the Risk of Diabetes – What to Do?

The media have greeted the arrival of generic Lipitor with reports of a study appearing this month in the Archives of Internal Medicine.  Analyses of data from the Women’s Health Initiative (WHI) prove further evidence of a link between the use of statin drugs and the occurrence of diabetes in postmenopausal women.  But the study is not the first to suggest such an association.  An analysis of 13 randomized clinical studies, published in the Lancet in 2010, found that statin users had a 9% increased risk for diabetes. Another meta-analysis of 5 controlled studies, published in the Journal of the American Medical Association last June, described an increase in risk in patients taking high rather than moderate doses of statins.

The new study echoes the findings of the two earlier ones.  Almost 154,000 women from the WHI, with an average age of 63, were followed for 12 years, during which time 10,200 of them had developed type 2 diabetes.  Statin use, which was recovered at enrollment and after 3 years, was established in 7% of the participants.  After adjusting for potential confounding factors (e.g. family history, excess body weight), it emerged that statin users were 1.48-times more likely to develop diabetes than non-users;  the rate for new diabetes during the study rose from 6.4% in the women not taking statins to 9.9% in the statin users.  This increased risk applied to all the statin drugs taken.

Taken together, these reports show a clear relationship between statin use and diabetes, but it is not a very close association.  Statins have a proven beneficial effect on heart attack, stroke, and mortality in patients with cardiovascular risk factors (e.g. high blood pressure, obesity, or existing diabetes), but these benefits are less obvious in healthy people.  As one expert has put it: “Every woman taking a statin needs to know her risk of heart disease, and she should ask her doctor if the statin is really necessary.” 

It’s probable that the study finding applies equally to men, although we shall have to wait for another study to show this.  In the meantime, there’s one important conclusion to be drawn: statins shouldn’t be given to perfectly healthy people, as some have suggested (“they should put it in the water”).  And the dose should be kept as low as possible in order to achieve the desired effect on blood lipids.  A piece on the USA Today website summarizes the situation pretty well.