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High Blood Pressure, Cholesterol Linked to Alzheimer's

June 14, 2001 -- We all know that high blood pressure and elevated cholesterol are key ingredients in the recipe for heart attack or stroke. Now there's evidence that they also increase the risk for Alzheimer's disease. When Finnish researchers checked in on subjects first tested 20 years earlier, they found that those who'd had either of these problems in middle age were more than twice as likely to have Alzheimer's now.

"There are so many people who have higher blood pressure and cholesterol values than they should have. That's important not only for the heart, but maybe also for the brain," says study leader Miia Kivipelto, MD, a research fellow in the department of neuroscience and neurology at the University of Kuopio. "The message is to treat hypertension and hypercholesterolemia early."

In the study, published in the June 16 edition of the British Medical Journal, nearly 1,500 randomly selected men and women were given a 20-year follow-up examination when they were about 73 years old. Kivipelto's team "found that having high systolic blood pressure or high cholesterol values at mid-life increased the risk of Alzheimer's disease significantly," she says. In fact, the risk was doubled. And for those who'd had both, the risk was three-and-half-times normal.

How high was too high? Kivipelto tells WebMD they used a limit of 160 for the systolic blood pressure, which is the top number on the reading. "But even 140 was a risk factor. For cholesterol, anything over 251 was [considered] too high," she says.

Keep in mind that those values were originally set more than 20 years ago. Current guidelines suggest maintaining blood pressure at or below 120/80 and total cholesterol below 200.

Anything above these levels is cause for concern, says Kivipelto, and you should be working toward lowering them. "If you have both of these risk factors, you really need to do something. The combination was especially dangerous," she says.

This isn't just more bad news. After all, cholesterol and blood pressure are things we can, for the most part, control. "These are the first modifiable risk factors for Alzheimer's disease," says Kivipelto. Treatment should begin as soon as possible, but that doesn't necessarily mean drugs. For example, she says, if you're overweight, simply losing weight will reduce your risk.

Emmanuel Mignot, MD, PhD, associate professor of psychiatry at Stanford University School of Medicine, tells WebMD that these findings are further proof that the body is not a set of distinct organs and systems, but a cohesive, integrated whole. When one area suffers damage, there can be seemingly unrelated consequences.

In his own study, published in the June 13 issue of The Journal of the American Medical Association, Mignot found that a genetic variant, ApoE e4, which is associated with Alzheimer's, is also associated with sleep apnea -- the condition where breathing becomes extremely shallow or stops completely during sleep. Sufferers jolt awake many times a night and feel exhausted during the day. There is a hypothesis that sleep apnea may result from subtle injuries to vessels in the area of the brain that regulates breathing.