Untreated high blood pressure linked to higher Alzheimer’s risk

A new study substantiates the link between untreated high blood pressure and an increased risk of Alzheimer’s disease for adults 60 and older.

The research, published Wednesday in the online issue of Neurology, the medical journal of the American Academy of Neurology, is a review of 14 international studies involving 31,250 people.

Participants, who were 72 years old on average, were followed for around four years for cognitive changes and dementia diagnoses.

Of the contingent studied, 1,415 developed Alzheimer’s disease.

Researchers found that participants with untreated high blood pressure had an increased risk of Alzheimer’s disease compared to people treated for high blood pressure and those without the chronic condition.

“High blood pressure is a leading cause of stroke and cerebrovascular disease, and yet it can be controlled with medication, reducing a person’s risk of these diseases,” said Dr. Matthew J. Lennon, a study author from the University of New South Wales in Australia. “Our meta-analysis looked at older people and found that not treating blood pressure may indeed increase a person’s risk.”

Lennon and his team analyzed blood pressure measurements, hypertension diagnoses and medication use among participants — 36% did not have high blood pressure, 51% were taking blood pressure medications and 9% had untreated high blood pressure.

Researchers found that participants with untreated high blood pressure had a 36% increased risk of Alzheimer’s disease compared to people without high blood pressure and a 42% increased risk of Alzheimer’s than those treating high blood pressure with medication.

Researchers emphasized that their results do not prove that untreated high blood pressure causes Alzheimer’s disease, they only show an association.

“Our meta-analysis that included people from around the world found that taking blood pressure medications was associated with decreased risk of Alzheimer’s disease throughout later life,” said Lennon. “These results suggest that treating high blood pressure as a person ages continues to be a crucial factor in reducing their risk of Alzheimer’s disease.”

Lennon’s team notes that a limitation of the research is that definitions for high blood pressure vary by country, an inconsistency that could lead to discrepancies in diagnosis.

Still, these findings support earlier research suggesting that high blood pressure in older adults can damage the brain. Autopsies in that study showed more signs of deterioration and hallmarks of Alzheimer’s disease in the brains of people with higher blood pressure than those with a BP closer to normal.

Experts say about 70% of Americans will develop high blood pressure at some point, but only 25% will get it under control.

Some 6.7 million Americans 65 and older suffer from Alzheimer’s, according to the Alzheimer’s Association. 

The new report comes in the wake of the Food and Drug Administration’s recent decision to approve two drugs shown to modestly slow Alzheimer’s, providing new options for patients in the early stages of the incurable disease, which destroys memory and thinking skills.