(Reuters Health) - Between 1999 and 2012, the use of cholesterol-lowering statin drugs increased among people over age 79 with no history of coronary heart disease, stroke or vascular disease, according to a new study.

People who have had a heart attack, stroke or diabetes are often prescribed a statin like atorvastatin (Lipitor) to reduce their risk of another event in the future, but there is little evidence for using the drugs preventively in the oldest old who have not had a heart attack or stroke, the authors write in a research letter in JAMA Internal Medicine.

“The fact that a lot of octogenarians are using statins was not particularly surprising, but the fact that around a third (of those) without heart disease reported use was quite shocking,” said Dr. Michael E. Johansen of the department of family medicine at The Ohio State University in Columbus, who coauthored the research letter.

Doctor recommendations likely influence patterns of statin use, Johansen told Reuters Health by email.

Researchers used a nationally representative survey of more than 13,000 U.S. elderly over age 79 who reported their medical conditions and prescription drug information. There were five rounds of the survey collected between 1999 and 2012.

In 1999-2000, almost nine percent of elderly people without a history of blood vessel disease were taking a statin. By 2011-2012, that had increased to 34 percent.

Statin use also increased among those who did have a history of coronary heart disease or stroke, the researchers found.

“Over the last decade the amount of use in this population nearly quadrupled,” Johansen said. The study ended in 2012, and in 2013, updated prescribing guidelines from the American Heart Association substantially increased the number of people without heart disease who are advised to take statins, so there could have been a further increase, he said.

“Most "experts" would agree that individuals at high-risk of developing vascular disease benefit from statins,” he said. “The controversy resolves around the definition of high-risk.”

Most guidelines do not include the very elderly without a history of cardiovascular disease because there have been few trials in this population, he said.

“A challenge in caring for older adults, especially adults in their late 70s and older, is that adults in this age group frequently are not included as participants in the research studies that serve as the foundation/evidence base for disease management/treatment,” said Dr. Christine T. Cigolle, director of the geriatric medicine fellowship at the University of Michigan Health System, who was not part of the new study.

“Out of necessity, researchers and clinicians then extrapolate findings from research involving the middle-aged and the “young-old” to these older adults,” Cigolle told Reuters Health by email.

Older adults on statins who are doing well should continue taking the statin, she said. For older adults who already have cardiovascular disease, the data support the use of moderate-intensity statin therapy, but do not clearly support starting high-intensity statin therapy, she said.

“Statins have numerous well known side effects, such as muscle aches,” Johansen said. “Perhaps the biggest risk of statins is that they could lead individuals to neglect other aspects of their cardiovascular health such as quitting smoking, eating a good diet, or getting regular exercise.”

“In individuals over 80, mobility is a particularly important to long-term health,” he said.

The elderly are often taking many pills to begin with and an added statin can increase the “pill burden,” he said.

(Reporting by Kathryn Doyle)