Study confirms a link, but does the risk outweigh the benefits?

Cholesterol-lowering drugs known as statins are often prescribed to reduce the risk of cardiovascular events like heart attack and stroke. Yet, according to a new study, postmenopausal women who take statins appear to be at increased risk of developing type 2 diabetes—not only a serious condition in and of itself, but a leading risk factor for the very cardiovascular disease they were hoping to avert in the first place.

This study isn't unique: Prior studies have also found a link between using statins and developing diabetes. Fortunately, the diabetes risk appears to be slight; at the same time, it raises concerns that patients should discuss with their doctors.

For this latest study, published in the Archives of Internal Medicine, researchers from several prominent medical schools and facilities analyzed data from the national Women's Health Initiative, one of the largest and longest studies of its kind. After reviewing questionnaires completed by 153,840 women ages 50 to 79, they found that postmenopausal women who took any kind of statin were 48 percent more likely to develop diabetes over a 12-year period than women who took no statins.

More studies needed

In this type of prospective study, the participants are healthy at the start of the study, enabling researchers to follow any sign of disease progression. This helps researchers recognize a relationship—but not a direct cause—between a condition and a characteristic. In this case, researchers looked for a link between statins and diabetes. Researchers couldn't explain the connection and recommended further research to establish a direct relationship, if any.

The same rate of diabetes risk was associated with statin use among women regardless of whether they had heart disease. Interestingly, women who had a body mass index (BMI) lower than 25 appeared more prone to diabetes than obese women with a BMI of 30 or higher. BMI indicates the amount of body fat a person has, based on height and weight.

Other study results

Prior studies have reported similar outcomes that suggest statins play a role in inducing type 2 diabetes:

  • A June 2011 analysis of pooled data from five clinical trials showed a 12 percent increased risk of developing diabetes among people taking high-dose statins over four years compared with those taking moderate-dose statins. Researchers from the United Kingdom calculated that 498 persons would need to be treated with high-dose therapy for one person to be diagnosed with diabetes. On the other hand, high-dose therapy would prevent one in 155 people from having a cardiac event.
  • A 9 percent risk of developing diabetes was associated with taking statins in a 2010 meta-analysis of 13 major statin trials. The risk was evident among statin users over a four-year period when compared with patients either not taking statins or undergoing other standard care.
  • In 2008, a large, controlled clinical trial investigating the benefits of using rouvastatin (Crestor) for people with low to moderate cholesterol found the drug to be associated with a 25 percent increased risk of developing diabetes.

The findings from these and the latest study highlight the need for further evaluation of statin therapy's risk and benefits. This may influence the practice of prescribing statins for their protective effects to people who don't have high cholesterol.

Doctor's Viewpoint

Simeon Margolis, M.D., Ph.D., Professor of Medicine & Biological Chemistry Johns Hopkins School of Medicine

Studies have shown that statins are highly effective in preventing cardiovascular events in people with type 2 diabetes. As a result, I believe that the potential risk of diabetes should not lessen the use of statins in individuals with known cardiovascular disease or in those at moderate or high cardiovascular risk.

People taking statins do need to get their blood sugar checked regularly to detect the possible onset of diabetes.

Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Publication Review By: the Editorial Staff at Healthcommunities.com

Published: 15 Jul 2013

Last Modified: 21 Jan 2015