Blood Pressure control does not slow decline in thinking and memory, finds a new study.
High blood pressure significantly increases risk for heart events and blood pressure control by drugs is beneficial for heart health. The new study has found that these drugs may not provide a similar benefit to the brain. The study, published in the online issue of Neurology®, found that when older people took candesartan plus hydrochlorothiazide to lower blood pressure or rosuvastatin to lower cholesterol or a combination of the two, the drugs did not slow decline in thinking and memory.
Numerous studies have demonstrated that hypertension increases the risk for cognitive impairment, vascular dementia, and Alzheimer’s disease. Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less
“Heart disease has been linked to problems with thinking and memory, so we examined whether managing heart disease with medications like blood pressure and cholesterol lowering drugs can reduce some of those cognitive problems,” said study author Jackie Bosch, PhD, of the Population Health Research Institute and the School of Rehabilitation Science at McMaster University in Hamilton, Ontario, Canada.
The study involved 1,626 people with an average age of 74 who had a moderate risk of heart disease, defined as having a 1 percent chance of having a heart attack or some other heart-related event during the year. Of the group, 45 percent had high blood pressure.
Participants were given thinking and memory tests at the beginning of the study. They received physical checkups every six months and then had thinking and memory tests again at the end of the study, an average of about six years later.
Participants took either a daily pill of 16 milligrams (mg) of candesartan and 12.5 mg of hydrochlorothiazide or a daily pill of 10 mg of rosuvastatin, a combination of the two, or placebo.
Researchers found that lowering blood pressure, or cholesterol, or both, with these drugs neither reduced nor increased the rate of cognitive decline in study participants when compared to those taking placebo.
“Statin use has previously been associated with cognitive impairment, but this study demonstrated that there was none, which is an important finding for those taking statins,” said Bosch.
Bosch added that taking medications for six years may not be long enough to prevent cognitive decline, so longer studies are needed.
A limitation of the study was that participants chose to participate, meaning they may have been healthier and at a lower risk of thinking and memory problems than the average population.
The study was funded by the Canadian Institutes of Health Research and AstraZeneca, which sells versions of the drugs studied.