Do Statins "Invite" Diabetes?

Lipitor, Crestor, and other statins are typically prescribed to help lower cholesterol and reduce heart disease risks, but new research again finds they may boost diabetes risk.

brown oral medication in blister packAnother study finds statin use linked to a slight increase in diabetes risk. (Photo: Unsplash, Anastasiia Ostapovych)

Statins have long been prescribed to lower cholesterol and blood pressure, in the process reducing the risk of having a heart attack or stroke. However, a new study has found once again that the risk reduction may come with a price: a higher risk of developing diabetes.

The new findings echo those of earlier research, says study leader Victoria Zigmont, PhD, MPH, assistant professor of public health at Southern Connecticut State University in New Haven, who conducted the research as part of her doctorate at Ohio State.1

Overall, she found, those who used statins had double the risk of getting diabetes as those who did not take the drugs. Among long-term users, the risk was even higher.1

Since 2012, the FDA has required statin makers to include information on the label about the medication increasing levels of hemoglobin A1C, in turn raising the risk of getting diabetes.2

One strength of the new study, Dr. Zigmont says, is access to ongoing measurements of the hemoglobin A1C, which some previous studies did not have.

Study Details

Dr. Zigmont's team evaluated 4,683 men and women, all in the Midwest, who did not have diabetes at the study start. Their average age was 46 and the average body mass index or BMI was 30, termed obese. The researchers looked at the participants' medical records over time. Over the study period, from 2011 through 2014, about 16% of the group, or 755, were prescribed statins.

The researchers monitored new onset diabetes diagnoses.Those who took the drugs for more than two years had more than three times the risk of getting diabetes than those who did not take the statins, Dr. Zigmont says.

During the study period, new onset diabetes was diagnosed in 112 or 14.8% of the statin users and in 198 or 5% of the non-users of statins.

The researchers also found that statin users in the study were more likely to have an elevated hemoglobin A1C, the two- to three-month look back at blood sugar levels. An A1C of 5.7% is defined as the beginning of ''prediabetes."

"There was an overall risk [to taking statins], but it was strongest at two years," Dr. Zigmont says. "And those using for more than two years tended to be older, and age drives the risk [for developing diabetes]."1

As other researchers also point out, Dr. Zigmont says she has found a link, but can't prove cause and effect. However, she says, "it's been established that statins can cause insulin resistance."  When that happens, your body can't use insulin as effectively, and the blood glucose doesn't get to the cells, causing it to build up in the bloodstream.

Expert Perspective

While a double or triple risk may sound very high, the new study ''is largely confirmatory of other studies that show a modest increase in the risk of being diagnosed with diabetes in people taking statins," says Jill Crandall, MD, Professor and Jacob A. and Jeanne E. Barkey Chair in Medicine and chief of endocrinology at the Albert Einstein College of Medicine, the Bronx.3

She has also studied the link between statins and diabetes, finding an increased risk of getting diabetes if statins are taken. A strength of the new study, she agrees, is that the researchers had access to repeated measurement of A1C over time and could look at other information such as waist circumference. A higher A1C and a high waist circumference increase the risk for diabetes, experts know.

However, the new study does not prove cause and effect, Dr. Crandall says, nor does her research. Other factors may be at play. People who have a greater risk of getting diabetes are more likely to be prescribed statins, and those on statins are likely to be tested more often for diabetes, for instance.

To prove cause and effect, a study that assigns groups similar in nature to take a statin or not, then follow them to see who gets diabetes is needed, she says. So far, the evidence is accumulating that taking statins ''does slightly increase the chances of being diagnosed with diabetes," Dr. Crandall says. She also adds, however, that it is most likely in those who are predisposed to it due to pre-diabetes, obesity or other risk factors.

It's important, too, to highlight the benefits of statin use in terms of preventing heart disease. "In most cases this outweighs the small risk of worsening glycemia [blood sugar],''  Dr. Crandall says.

Take-Home Points from Both Experts

Dr. Crandall urges people to talk to their doctors about whether the benefits of a statin, for them, outweigh the risks. If you do decide to take a statin, your doctor should monitor your blood sugar closely to detect any abnormal increases, she says.

According to Dr. Zigmont, ''there is a trend to prescribing them [statins] earlier." Based on her finding that long-term use boosts the risk even more, she says that is something for everyone to be aware of.

Despite the finding of an increased risk of getting diabetes with statin use, Dr. Zigmont sees a potential bright side to her study findings. "Maybe the finding will inspire people to exercise," she says, as well as pay closer attention to eating more healthfully. Following those habits may just bring their cholesterol in line enough to avoid the statin and their weight to a level that reduces the diabetes risk associated with obesity.

Updated on: July 24, 2019
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