Study: High Cholesterol Increases Women's Stroke Risk / February 20, 2007

Controlling cholesterol may be even more important for women than previously thought. A new study in the journal Neurology finds healthy women with no history of heart disease or stroke significantly increase their chances of having a stroke if they have high cholesterol.

The study tracked 27,000 women over eleven years.

" Our findings further underscore the importance of cholesterol levels as a risk factor for stroke, even if you have no history of heart disease and are otherwise healthy," said study author Tobias Kurth, MD, ScD, with Brigham and Women's Hospital in Boston, and a member of the American Academy of Neurology.

All of the women in the study were health care professionals who were at least age 45, had no history of cardiovascular disease, cancer, or other major illness. Cholesterol levels were taken at the beginning of the study.

According to researchers, 282 strokes occurred during the 11-year period, meaning nine out of every 10,000 women had a stroke each year. The study found a strong association between total cholesterol levels and later stroke.

" Our findings show otherwise healthy women with high cholesterol were more than twice as likely to suffer a stroke compared to healthy women with lower cholesterol levels," said Kurth. "Our data strongly supports the notion that cholesterol levels are a biologic risk factor for stroke and that avoiding unfavorable cholesterol levels may help prevent stroke."

Kurth said there were several limitations to the study, including that cholesterol levels were measured only once and that participants in the study were all health professionals and mostly white.

The study was supported by the National Heart, Lung, and Blood Institute and the National Cancer Institute in Bethesda, Maryland, and grants from the Donald W. Reynolds Foundation and the Leducq Foundation.

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This study reports 282 strokes in 27,000 women over 10 years. It is typical of most studies: they collect lots of data and then come to unwarranted conclusions

The number of people studied is impressive and the results are probably statistically valid -- HOWEVER ... If the ratio is 2 to 1 as they say -- that would be about 200 strokes for the high cholesterol and 100 strokes for "normal". So -- at worst, the high cholesterol "caused" 100 strokes in about 13,500 women. That is one stroke for every 135 women -- or less than 1% over 10 years.

I just can't see getting excited about a 1% chance of anything over a 10 year period.

And this says NOTHING about side effects and death from other causes.

And -- I bet if you read the actual study -- there will be all sorts of holes in their conclusions.

First of all -- the women with "high" cholesterol may have an underlying condition wherein the cholesterol is actually working to repair damage to cell membranes (that is its job!). Reducing the cholesterol may be harmful. Unless this posssibility is taken into consideration by reducing the cholesterol and seeing if that reduction helps or hinders mortality -- the researchers will never know if it is wise to reduce cholesterol.

And WHAT ABOUT heart attacks? Did they go up or down in high-cholesterol women?

This is not quite junk science in my opinion -- it may be a good base on which to build -- but as it stands, I am not impressed by the incomplete and misleading conclusion that "High Cholesterol Increases Women's Stroke Risk".

MRC