People suffering from the most common form of diabetes could sharply cut their risk for heart attacks and strokes by taking a cholesterol-lowering drug even if they have normal cholesterol levels, according to a major new study.
The study of more than 2,800 patients with Type 2 diabetes found that those who took the cholesterol drug Lipitor were more than one-third less likely to have a heart attack, nearly half as likely to have a stroke and about one-third less likely to die from any form of cardiovascular disease.
"This is a landmark study with watertight data showing clear evidence of a benefit that warrants people to really look at their treatment of this group of patients," said the study's lead author, Helen Colhoun, a professor at University College Dublin. The study was terminated two years early because the results were so striking.
Most other experts agreed, saying the findings provide the most convincing evidence yet that most diabetics should consider taking the drugs regardless of their cholesterol levels. The research is the latest in a series of studies showing that the widely popular class of cholesterol-lowering drugs called statins could benefit far more people than are taking them.
"This is another extraordinary result," said Peter Libby, a Harvard Medical School cardiologist.
Although the study, being published in Saturday's issue of the Lancet medical journal, received some funding from Lipitor's maker, Pfizer Inc., it was supported primarily by the British government and the British equivalent of the American Diabetes Association and conducted independently of the company, Colhoun said.
About 17 million Americans suffer from Type 2 diabetes, which has been increasing rapidly in the United States because of the rising number of people who are overweight. Doctors have long known that diabetes sharply increases the risk for heart attacks and strokes, but patients generally do not take statins unless they have high cholesterol levels.
Evidence has been mounting, however, that many diabetics could benefit from the drugs even if their cholesterol levels fall within what is considered normal under current guidelines. A panel of experts assembled by the U.S. government last month recommended that millions more Americans at risk for heart disease for any reason consider taking the drugs to reduce their risk, including many diabetics.
The move was based on accumulating evidence that there is added benefit to driving cholesterol levels -- especially levels of LDL cholesterol, the "bad" cholesterol -- lower than what has traditionally been considered normal. In addition, a growing body of evidence suggests that statins may cut the risk for heart attacks and strokes in other ways, such as reducing inflammation in the body or improving blood vessel function.
But specific recommendations for diabetics have been cautious and mixed because none of the studies suggesting there may be a benefit was specifically designed to examine that question.
The new study is the first aimed at testing whether a statin could help diabetics. Researchers gave 2,838 Type 2 diabetics at 132 centers in Britain and Ireland with normal cholesterol levels either 10 milligrams of Lipitor or a placebo every day.
After an average of four years, those taking Lipitor were 36 percent less likely to have had a heart attack or have died suddenly because of their hearts stopping, 48 percent less likely to have had a stroke and 37 percent less likely to have suffered any serious adverse cardiovascular event. The study was terminated two years early so participants could be notified and get the benefit of treatment, which appeared to begin after only about a year of treatment.
"It's been controversial whether for diabetics who don't have high cholesterol it's worthwhile lowering their cholesterol. What we've shown is that even those at the bottom of the levels for cholesterol have exactly the same benefit as those at the higher levels," Colhoun said. "What we're saying is that anyone with Type 2 diabetes should be considered for therapy."
Not everyone agreed. In an editorial accompanying the study, Abhimanyu Garg, a professor of medicine at the University of Texas Southwestern Medical Center in Dallas, said it is premature to recommend cholesterol drugs for all diabetics.
"You can't generalize your recommendations based on one trial," Garg said in a telephone interview. "A lot of people are going very fast to drug therapy. We should make all efforts to lower cholesterol by dietary means, by exercising, by weight loss, before we take the step of treating patients with cholesterol-lowering drugs."
Other experts agreed that lifestyle changes should be tried first but added that the findings are so compelling that more doctors and their patients should at least consider drugs.
"I think most people have now come around to the view that cholesterol-lowering is quite important in diabetes," said Scott Grundy, who works with Garg at the University of Texas Southwestern Medical Center and headed the federal panel that recently issued new guidelines on cholesterol lowering.
Eric Topol, a cardiologist at the Cleveland Clinic, agreed, calling Garg's editorial "completely off base."
"This shows a striking benefit," Topol said. "This trial is a really big step forward in terms of demonstrating without any question the benefits of statins among . . . diabetics."
The American Diabetes Association will consider the new findings when it issues new guidelines in January on the use of cholesterol drugs for diabetics, said Nathaniel Clark, the group's vice president of clinical affairs.