Do Statins Raise Odds for Type 2 Diabetes?
"In a group of people at high risk of type 2 diabetes, statins do seem to increase the risk of developing diabetes by about 30 percent," said the study's lead author, Dr. Jill Crandall. She's a professor of medicine and director of the diabetes clinical trials unit at Albert Einstein College of Medicine in New York City.
But, she added, that doesn't mean anyone should give up on statins.
"The benefits of statins in terms of cardiovascular risk are so strong and so well established that our recommendation isn't that people should stop taking statins, but people should be monitored for the development of diabetes while on a statin," she explained.
At least one other diabetes expert agreed that statins are still beneficial for those at risk of heart trouble.
Dr. Daniel Donovan Jr. is professor of medicine and director of clinical research at the Icahn School of Medicine at Mount Sinai Diabetes, Obesity and Metabolism Institute in New York City.
"We still need to give statins when LDL (bad) cholesterol isn't under control. A statin intervention can lower the risk of a cardiovascular event by 40 percent, and it's possible the diabetes may have been destined to happen," he said.
The new study is an analysis of data collected from another ongoing study. More than 3,200 adults were recruited from 27 diabetes centers across the United States for the study.
The research goal was to prevent the progression of type 2 diabetes in people with a high risk of the disease, Crandall said. All of the study participants were overweight or obese. They also all showed signs that they weren't metabolizing sugar properly at the start of the study, but not poorly enough to be diagnosed with type 2 diabetes.
Study volunteers were randomly chosen to get treatment with lifestyle changes that would lead to modest weight loss, the drug metformin or a placebo pill.
At the end of the intervention, they were asked to participate in the 10-year follow-up program. They had their blood sugar levels measured twice a year, and their statin use was tracked, too.
At the start of the follow-up period, 4 percent of participants were taking statins. At the end, about one-third were.
Simvastatin (Zocor) and atorvastatin (Lipitor) were the most commonly used statins.
The study was an observational study, so it couldn't show a cause and effect relationship.
However, Crandall said the researchers measured levels of insulin secretion and insulin resistance. Insulin is a hormone that helps the body usher the sugar from foods into the body's cells to be used as fuel.
Crandall said insulin secretion goes down when people take statins. Less insulin would lead to higher blood sugar levels. She said there was no indication that statins affected insulin resistance.
Donovan added that the study provides important information. "But I don't think the message is stop statins," he said. "Most people are probably developing heart disease before diabetes, and it's important to treat the risk factors you can."
Though they weren't included in this study, people who already have type 2 diabetes should be closely monitored for increases in blood sugar when they start taking a statin, Crandall said. "The evidence so far is rather limited, but there have certainly been anecdotal reports of blood sugar being higher when someone starts statins," she said.
She also suggested that blood sugar levels likely aren't as much of a concern for those without diabetes or risk factors for diabetes when starting a statin. Besides excess weight, those risks include older age, high blood pressure and a family history of diabetes.
Crandall added that there are many people 50 and over with prediabetes who don't know it, so it could be an issue for them.
Findings from the study were published online Oct. 23 in BMJ Open Diabetes Research & Care.
Learn more about the link between type 2 diabetes and statins from the American Heart Association journal Circulation.
Posted: October 2017