Public health officials have been warning people for years that high cholesterol and high blood pressure are bad for the brain. The fear is that hypertension and elevated LDL cholesterol will lead to cognitive decline as we age. The HOPE-3 trial was designed to determine whether lowering blood pressure and cholesterol could reduce the risks of heart attacks, strokes and death.
Equally important was the test of cognitive function. We suspect that a lot of health professionals assumed that reducing blood pressure and cholesterol would help the brain. By most standards, the results of this huge study were disappointing, especially when it came to tests of mental function.
What They Did:
The HOPE-3 trial involved 12,705 people at intermediate risk for cardiovascular disease. They were followed for 5.6 years, which is a long time for such studies. Here is how the study was organized:
- Every participant took two pills:
- 3,180 took rosuvastatin (Crestor) plus candesartan and hydrochlorothiazide (Atacand HCT)
- 3,181 took rosuvastatin plus placebo
- 3,176 took candesartan & HCTZ plus placebo
- 3,168 took placebo plus placebo
What They Found:
According to one of the key investigators, there was no difference in cognitive function after nearly six years between those taking blood pressure medications vs. those taking placebo. Ditto for those taking the cholesterol-lowering drug rosuvastatin. The combined treatment (blood pressure plus cholesterol lowering) also did not improve memory or brain function. The investigators put a positive spin on the trial by saying that the statin did not cause cognitive decline.
We were intrigued to learn from the key researcher that those with the lowest systolic blood pressure at the start of the trial seemed to do a bit worse on cognitive function tests while those with the highest systolic blood pressure at the start seemed to do a bit better on those tests. She pointed out that these results were not statistically significant. She added that those with the highest LDL cholesterol at the start of the trial also seemed to do a bit better cognitively, but again that metric was not statistically significant.
Ignored Amidst the Spin:
Just as pundits like to spin the results of debates or other political events, so too health experts like to spin the results of clinical trials. The HOPE-3 trial has been heralded as great evidence that statin-type cholesterol-lowering drugs are fabulous drugs for preventing heart attacks, strokes and death. Let’s look at the actual data.
The relative risk reduction for heart attacks or strokes was 24 percent in people taking the statin-type drug Crestor for nearly six years. Sounds pretty impressive, right? When you look at the absolute risk reduction it was only about 1.1 percent. Roughly one person out of 100 got a meaningful benefit. When it came to blood pressure reduction, no one benefitted after six years of treatment.
Take Home Message:
While a 24 percent relative risk reduction in cardiovascular events seems impressive, an actual risk reduction of roughly one per hundred seems less exciting to us. As the authors themselves noted, you would need to treat 91 people in order to prevent one cardiovascular event. That means that roughly 90 people would get zero benefit from taking rosuvastatin for nearly six years. It’s also hard to explain why lowering blood pressure for almost six years did not lead to measurable improvement.
Finally, what are we to make of the blood pressure reduction and cognitive function test results? Lowering blood pressure with medications was supposed to help the brain, especially in older people. We have not seen a good explanation for this disappointing outcome. Perhaps lowering cholesterol and reducing blood pressure do not help the brain after all.
If you would like to learn more about preventing dementia you may find our article “How to Prevent Alzheimer’s Disease” of interest.
You may also wish to listen to our interview with Dale Bredeson, MD, of great interest. Here is a link to our one-hour radio program, “Learn How One Doctor Is Reversing Alzheimer’s.” You can listen to the streaming audio version for free (see the green bar at the top of the page) or download an mp3 version for $2.99.
