The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


Do Statin Drugs Increase the Risk of Developing Diabetes?

Posted in
Live well

Monday, Mar 11, 2013

Cardiovascular disease (CVD), which is a general term to describe all diseases related to the heart and circulatory system, has been the leading cause of death in the U.S. for the past century. Each year, nearly 1 million Americans die from CVD. Two of the most common types of CVD are coronary heart disease and stroke. Because abnormal blood cholesterol level is a major risk factor for both coronary heart disease and stroke, the discovery of statin drugs in the late 1980’s was a major breakthrough for the prevention and treatment of these two conditions.

Statin drugs have powerful lowering effects on blood LDL cholesterol and triglyceride levels. Common statins include Atorvastatin (Lipitor), Lovastatin (Mevacor), Pravastatin (Pravachol), and Simvastatin (Zocor). Numerous long-term studies published over the past quarter century  have shown that for every 1% lowering of LDL cholesterol level, the risk of heart attack and stroke is reduced by ~2-3%. Thus, it is indisputable that statins significantly decrease the risk of  common cardiovascular events, and that these drugs are an important part of the arsenal we have for preventing CVD.

However, as is the case for all medications, statins have risks as well as benefits. One of the  earliest-noted and most common side effects of statin use is myalgia (muscle pain), which occurs approximately 10% of the time. More recently, several studies have shown an increased risk of developing diabetes among statin users. However, before anyone is tempted to jump off the statin bandwagon, let’s examine these risks carefully.

One way that scientists evaluate published studies is to combine similar studies into one very large study. This technique is called a meta-analysis. A recent meta-analysis was published in the American Journal of Cardiology by Navarese and colleagues. Seventeen studies, utilizing a total of 113,394 non-diabetic patients were evaluated. All of the studies examined either the effects of a statin vs. placebo, or the effects of moderate vs. high dose statin on the risk of developing diabetes. The findings from this study indicated that the risk of developing diabetes varied according to the type and dose of statin used. For example, pravastatin (40 mg/day) was associated with only a 7% increased risk for development of diabetes; this risk was not significantly significant. On the other hand, rosuvastatin (20 mg/day) was associated with a 25% increased risk, while atorvastatin (80 mg/day) was associated with a 15% increased risk.

Several additional studies on this important topic were presented at the 2012 meeting of the American Heart Association (AHA). All of the studies utilized patients who did not have diabetes at baseline. In one of these studies, patients were divided into two groups; those at low risk for future development of diabetes and those at high risk. For low risk patients, only 3% of those who were prescribed Atorvastatin or Simvastatin developed diabetes during the follow-up period. In contrast, 12% of those at high risk developed diabetes. If you are wondering how they determined who was at low or high risk for future diabetes at the beginning of the studies, they considered factors such as age, family history of diabetes, physical activity level, adiposity indicators like BMI and waist circumference, etc.

An additional important finding presented at the AHA meeting was that using a combination of statins plus a diuretic seems to increase the risk for developing diabetes more so than use of a statin alone. The mechanism for this is unknown.

So, what to make of these findings?  According to Dr. Barton Duell, a presenter at the AHA meeting “Although it does appear that statins may increase the chance of diabetes in high-risk patients, this should not stop us from using these drugs, as this small risk is outweighed by the substantial reduction in cardiovascular events.” Similarly, Dr. David Waters, another presenter said, “New-onset diabetes may count as one stroke against, but dropping dead from a cardiovascular event could be 100 strokes against. If you had to choose between one of these events, you are going to choose the diabetes.”  We have provided a graphical representation of these comments in Figure 1 below.

For non-diabetic statin users who wish to decrease their small risk of developing diabetes, meeting or exceeding the current public health guidelines for physical activity is a good place to start. The American College of Sports Medicine and the AHA recommend a minimum of 150 minutes/week of moderate intensity aerobic activity as well as a minimum of two days a week of strength building activity. Additionally, losing weight if overweight and eating a high fiber diet are also tried and true strategies for preventing diabetes. Talk with your primary care health provider to learn more about preventing CVD and diabetes.


Navarese, E., et al. (2013). Meta-analysis of impact of different types and doses of statins on new-onset diabetes mellitus. American J Cardiol, published online January 25.

Waters D., et al. (2013). Cardiovascular event reduction versus new-onset diabetes during atorvastatin therapy: effect of baseline risk factors for diabetes. J Am Coll Cardiol, 61(2), 148-152.