NEW YORK (Reuters Health) - Cholesterol-lowering drugs may be linked to an increased risk of diabetes, according to a new study of middle-aged and older women.
But researchers said that shouldn't dissuade people with heart disease -- or at risk of it -- from taking so-called statins.
Instead, statin users should try to reduce their risk of diabetes in other ways, such as by losing weight, and should have their blood sugar regularly monitored, they said.
"The conclusion still stands that overall, those people who've got existing heart disease or have had previous strokes, they still would get vast benefits from statins," as would those at high risk for heart disease, said Naveed Sattar, a metabolism and diabetes researcher at the University of Glasgow, UK.
Instead, the finding "may make us a bit more cautious about putting statins in the water, for example," Sattar, who wasn't involved in the new study, told Reuters Health.
In other words, not all people with few heart risks should be taking the drugs, as some researchers have suggested, because they aren't side effect-free.
For their report, Dr. Yunsheng Ma of the University of Massachusetts Medical School in Worchester and his colleagues used data from the Women's Health Initiative, including more than 150,000 diabetes-free women in their 50s, 60s and 70s.
As part of that larger trial, some of the women were prescribed diet changes or took daily hormone therapy or vitamins, while others weren't told to change their diet or lifestyle.
At the start of the study in the mid-1990s, women filled out health questionnaires that included whether or not they were taking statins, as well as information on other diabetes risks, such as weight and activity levels. The researchers then followed participants for six to seven years, on average, and tracked how many of them were diagnosed with diabetes.
In total, just over 10,200 women developed diabetes. Ma's team found that the women who reported using any kind of statin at the start of the study -- about one in 14 of the participants -- were 48 percent more likely to be diagnosed with diabetes than those not taking statins.
That was after considering other known diabetes risks, the researchers reported Monday in the Archives of Internal Medicine.
About one-quarter of adults age 45 and older in the United States now take statins -- which run anywhere from $11 to over $200 per month -- to lower their cholesterol and heart disease risks.
Previous studies, mostly in men, have suggested a smaller, 10-to-12-percent increase in diabetes among statin users, according to Sattar.
Those numbers may be more accurate because they come from trials in which participants were randomly assigned to take a statin or not, which can better account for possible differences in groups of patients, he added.
What's more, this type of "observational" study can't prove cause-and-effect.
Still, "broadly speaking, this kind of confirms that stains may well increase diabetes risk," Sattar said. Why that's the case isn't totally clear, he said, but statins' effects on the muscles and liver may lead the body to make slightly more sugar than it normally would, or cause users to exercise a bit less.
Dr. David Jenkins, a nutrition and chronic disease researcher from the University of Toronto, said the medical community has accepted an increased risk of diabetes with statins as "a very fair trade-off," since statins lower the risk of heart disease, the primary concern related to diabetes.
Still, the findings highlight the importance of monitoring risks for diabetes, including blood sugar levels, and encouraging patients who are on the drugs to try to eat better and be physically active, researchers said.
"Statins will always be with us, they will always be valuable, and we will always prescribe them," Jenkins, who wasn't tied to the new research, told Reuters Health. But, "Statins, brilliant as they are, haven't actually completely precluded the use of changing one's diet and one's lifestyle."
Ma told Reuters Health that there's a need for future studies to evaluate both the risks and benefits of statins for people of different ages and genders, with and without heart disease. For some with high cholesterol, he said, a smart choice may be starting out with changes in diet and lifestyle, before going straight to a statin.
"Each person deserves a careful risk versus benefit assessment," agreed his co-author, Annie Culver, from the Mayo Clinic in Rochester, Minnesota.
Then, she told Reuters Health, "Once (you) receive the statins, don't abandon the idea of making lifestyle changes."
SOURCE: bit.ly/fO01ME Archives of Internal Medicine, online January 9, 2012.