Do Statins Cause Diabetes? Heart Attacks Likely to Pose Greater Concern

with Victoria Zigmont, PhD, MPH, Joshua Knowles, MD, PhD,
and Seth J. Baum, MD

Several recent studies have presented data suggesting a relationship between statin use and a greater risk of developing new onset type 2 diabetes (T2D).1,2 The latest findings reinforce this apparent link, and go further to indicate that the longer the person takes statin therapy, the greater the likelihood of developing diabetes.3 However, there’s more to it than that.

The study conducted by a team of researchers at Ohio State University looked at insurance claims for patients with one or more risk factors for cardiovascular disease (CVD) or who have had a cardiovascular event to assess how likely they are to develop diabetes after beginning statin therapy.3

Taking a statin remains necessary to reduce your risk of heart disease.Despite news reports raising questions about the possibility that statins may increase the risk of developing diabetes, the benefits of taking statins remain. Photo: 123rf

A Closer Look at the Diabetes Risk in Individuals with Heart Disease  

No one with previously diagnosed type 2 diabetes nor anyone with a diagnosis of T2D within 90 days of enrollment were included in the study, according to lead author, Victoria Zigmont, PhD, MPH, assistant professor of public health at Southern Connecticut State University in New Haven.

Instead, they were looking for anyone who developed a hemoglobin A1c (A1c) level over 6.0%, and newly diagnosed diabetes after starting on statin therapy to address high blood cholesterol.3 More than 4,500 patients met the inclusion criteria and were counted in the final analyses.

Individuals who had been prescribed a statin to treat their high blood cholesterol were more likely to have an elevated A1c level over 6.0% than the group not taking the cholesterol-lowering medication;3 the trend shows that statin users were more likely to be diagnosed with new onset diabetes than non-statin users.

These findings uncover a greater adverse impact based on the duration of statin therapy.3 In fact, individuals taking a statin for more than two years are more likely to develop new onset diabetes than those on a statin for shorter term treatment, says Dr. Zigmont. Most people who start statin therapy will need to take it for the foreseeable future.

While the authors did not examine statin therapy based on brand (type) or the dose (lower at 20 mg versus higher at 40 mg, for example), they did report on the classification of statins taken— lipophilic or hydrophilic—as possible variables in the increased risk of prompting development of type 2 diabetes, across the more than 7,000 patients whose records were evaluated.3

There is no statistical difference in problematic blood glucose levels or signs of diabetes regardless of the type of statin therapy prescribed so that patients who received either lipophilic or hydrophilic statins showed a similar risk of developing T2D,3 according to the researchers.

Avoiding Statins Poses Greater Risk of Cardiovascular Disease 

Since heart disease and stroke are the leading cause of death in the United States, and statin use has been shown to reduce heart attacks and other cardiovascular events by as much as 37%, they are among the most commonly prescribed drugs in the nation, with more than 27% of people ages 40 to 59 using them.4,5

These findings as well as those of earlier studies worry many physicians who fear that patients who hear these reports in the news may refuse to heed medical advice about continuing to take a statin if they are already taking one, or to rebuff a recommendation to begin taking a statin when your blood results indicate you have high cholesterol.

“[Patients] worry about the risk of adverse effects even as the most important side effect of using statins is greater lifespan and the chance of facing fewer cardiovascular events,” Joshua Knowles, MD, PhD, assistant professor of cardiology at Stanford University tells EndocrineWeb. “It’s clear that statins greatly reduce the risk of heart attacks and stroke even in some people whose blood choleseterol is in the normal range.”

Unfortunately, we’ve seen one study after another raising concerns about possible side effects that can come with statin use, in the past few years, which has given patients reason to question taking the medication, says Dr. Knowles. He calls these concerns valid but out of proportion. The benefits still far outweigh any slight downside. For example, leg and muscle pain happens in just 5% of patients, and truly serious problems are “vanishingly rare”.

To Avoid Diabetes, More Urgent to Focus on Addressing Weight and Lifestyle

That people are “mildly more likely” to become diabetic is something to consider, he says;  other study results had suggested the increased risk of developing type 2 diabetes is about 9%, he says, and is almost completely seen in individuals with a higher waist circumference, diagnosis of obesity, and higher blood triglyceride levels.

“Statins seem to take anyone who almost has diabetes and push them over the edge,” says Dr. Knowles. More to the point, the data suggest that the risks of T2D are similar whether you take a statin or not.

“If you don’t have prediabetes, are not overweight, and don’t high triglycerides, your risk is closer to 3% over the next 7 to 8 years., and your risk is nearly the same at 2% if you don’t take a statin. However, if you have prediabetes and are overweight, your risk without a statin is 15 to 18% and about 22% with a statin,” he says.

The real significance of this latest study and other reports is that lifestyle changes, such as reducing excess weight and increasing physical activity can help avoid developing diabetes and reducing the risks associated with cardiovascular disease, Dr. Knowles says. “The risks of not taking statins massively outweigh any risk that may come from taking them.”

Getting a Second Option on Strategies to Reduce Risks of Diabetes

“Whenever we prescribe any medication, we run a risk/benefit analysis,” says Seth J. Baum, MD, immediate past president of the American Society for Preventive Cardiology, and medical director of women’s preventive cardiology at the Boca Raton Regional Medical Center in Florida who reviewed the study findings for EndocrineWeb.

“We look at the particular patient and consider any risks for cardiovascular disease including events like stroke. If you have a high risk of a cardiac event, it’s a no brainer—you should take a statin.” It’s when there is a more modest risk that a more in-depth discussion should take place regarding whether potential risks outweigh the known benefits of taking a statin.

In effect, it comes down to the fact that having cardiovascular disease poses a more imminent risk than developing type 2 diabetes, says Dr. Baum. “Diabetes is a continuum based on blood glucose and A1c levels,” he says. “You can’t say that someone with a blood sugar level of 6.5% is much sicker than someone with an A1c of 6.3%. Maybe you’ve crossed a numeric threshold, but what has really changed? Whereas with heart disease, it’s binary. You have a stroke, or you don’t. You die or you don’t.”

In either case, the best advice you can heed is to adopt strategies known to reduce your risk of diabetes by moving more, eating more wisely/better, and making changes that support weight loss, as needed, as these lifestyle behaviors are the best and surest way to reduce your risk of develop both conditions (heart disease and type 2 diabetes), says Dr. Baum.

By tackling any disease risk at the level of weight control, diet and exercise, it’s possible that a motivated individual can make the need for statin moot. “We always want to see people take appropriate steps to make lifestyle changes to manage the disease risk. This is the best way to push them to reduce the chance of develop heart disease and/or diabetes. If the risk becomes low enough, you will be able to avoid the need to take statin,” he says, and that is the simplest way to avoid any concerns about risks of developing diabetes, which of course is the ultimate goal.

Once you start taking a statin, you should see your doctor regularly to have your blood sugar checked,6 according to the Food and Drug Administration.

It could be that there are individual risk factors may precipitate developing diabetes that haven’t been discovered yet, says Dr. Zigmont. There has been some discussion about a possible mechanism by which statins increase insulin resistance; however, the answer remains elusive, so more study is required. However, "it is important to take cholesterol-lowering medication when your doctor prescribes it because you have a higher risk of cardiovascular disease."

"If you want to learn more about statins, the Mayo Clinic has developed a patient tool that can help guide you to start a discussion with doctor: Statin Decision Aid

Focus on Healthier Strategies to Ward Off Diabetes & Heart Disease

“Patients should think more about preventing diabetes and cardiovascular disease,” says Dr. Zigmont, “as obesity is a risk factor for both conditions.” 

Reinforcing the points made by Dr. Baum, she urges individuals who are concerned about diabetes to put aside any worry about statins, and instead to double down on making lifestyle changes that can go a long way in reducing your risk of developing diabetes. After all, we know that individuals who avoid weight gain, and those who manage to lose weight have the best chance of reversing the fallout of diabetes and can avoid the complications that come with this otherwise chronic, lifelong disease.

Conversely, statins are needed specifically to reduce the risk of heart attack and stroke, and they are incredibly effective at doing so, she says. It is important to take cholesterol-lowering mediation when you have a higher risk of cardiovascular disease, especially if you are a woman in post-menopause.

For those of you who are concerned about side effects, there is anecdotal evidence that changing the brand of statin may relieve some adverse symptoms rather than stopping statin therapy. Also, dose changes can help to manage any negative reactions such as the rare occurance of muscle pain, while still allowing for the huge benefits, lessening the chance that you’ll have a cardiac event. 

“I hope more research will examine the big datasests that are available,” Dr. Zigmont says. “The long-term benefits and side effects based on type of statin and dose of the statin remain to be discovered and we need to more research focusing on the effects of stains on human metabolism; in the meantime, pharmacy claims provide a reliable way to discover more about statins and their impact on patients.”

Dr Baum too would like to see more robust research conducted, but he believes that going forward, the focus should be on hard science to determine both the mechanism for increased insulin resistance in some people, and to explore what could potentially mitigate this problem.

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