The researchers included Florence Pasquier, MD, PhD, of the neurology department at University Hospital in Lille, France.
The study appears in the Journal of Neurology, Neurosurgery, and Psychiatry.
Counting Cholesterol Drugs
Pasquier and colleagues studied 342 Alzheimer's patients for about three years.
The patients were about 73 years old when the study started. Most were women. Their general health and educational backgrounds were similar. Here's how they ranked for cholesterol:
- 108 patients had normal cholesterol without taking drugs.
- 105 patients had high cholesterol but weren't taking cholesterol drugs.
- 129 patients were taking drugs for cholesterol problems.
Nearly half of those drugs were statins, a widely used class of cholesterol-lowering medicines. Other patients were taking fibrates, a different class of cholesterol cutters. Some had switched between the two drug classes.
All of the patients lost some ground on the mental tests each year. Those taking cholesterol drugs had the smallest drop in test scores.
Declines in mental-status testing scores were as follows:
- 1.5 points per year for those taking cholesterol drugs.
- 2.4 points per year for those with high cholesterol and no cholesterol drugs.
- 2.6 points per year for those with normal cholesterol and no cholesterol drugs.
The study was too small to detect differences between patients taking statins and those taking fibrates.
Keep in Mind
No one was assigned to take any drug. The researchers just tracked the patients' medications and test scores.
The researchers note a few factors that could have made a difference:
- Patients taking cholesterol drugs tended to have higher scores to begin with.
- The mental test might not be the best at measuring Alzheimer's progression.
- Several patients were taking antidepressants called selective serotonin reuptake inhibitors (SSRIs).
If cholesterol drugs slow Alzheimer's, it's not clear how that works. Besides cutting cholesterol, the drugs also counter inflammation, write the researchers.
Their bottom line: The pattern looks interesting enough to deserve a direct test. Use of cholesterol drugs should be taken into account in other drug studies of Alzheimer's progression, they write.
Detailed images of the patients' brains would also have helped, states a journal editorial.
The editorialist was Frank-Erik de Leeuw, PhD. He works in Nijmegen, Netherlands, in the neurology department at University Medical Centre and wasn't involved in the study.
Other evidence for a cause-and-effect relationship between cholesterol, its treatment, and Alzheimer's has been "conflicting," writes de Leeuw. Further studies need to be done to evaluate this possible association.