Patients taking drugs known as ACE inhibitors that are used to treat high blood pressure and heart failure had lower rates of deterioration caused by certain types of dementia, according to researchers who reviewed Canadian hospital records.
The researchers led by William Molloy of University College Cork in Ireland conducted what is known as an observational study, by looking at records of past treatment of 361 dementia patients at two memory clinics in Ontario, Canada. Those who were taking ACE inhibitors showed a smaller drop in their score on a test measuring cognitive ability than those who weren’t on the drugs, according to the study published today in BMJ Open, an online journal.
The findings indicate that ACE inhibitors hold promise as an inexpensive way to ease the burden of dementia, Molloy said. The affliction will probably become more common as the world’s population ages. A further study is needed to examine if ACE inhibitors also prevent the onset of dementia, Molloy said.
“The $64,000 question is will they prevent dementia?” Molloy said in a phone interview.
The results merit additional study because treating blood pressure in mid-life is known to lower dementia risk, said A. David Smith, professor emeritus of pharmacology at Oxford University in England. He said today’s study doesn’t show that ACE inhibitors slow the disease’s progression because significant treatment effects were limited to a small number of patients who’d been newly prescribed the drugs and 80 percent were on other medicines to manage the symptoms of dementia.
“It’s a study that hasn’t produced convincing evidence,” Smith said in a telephone interview.
ACE inhibitors lower blood pressure by blocking angiotensin-converting enzymes in the body’s blood pressure regulation system and reducing blood volume and tension in blood vessels. Most are generic and cost pennies a day.
Alzheimer’s disease and dementia mostly affect older people and the number afflicted by the conditions is growing worldwide as populations age. The World Health Organization predicted dementia cases would triple from 36 million worldwide in 2010 to 115 million in 2050.
Scores on one test measuring cognitive ability fell 1.8 points in patients suffering from vascular dementia and dementia from Alzheimer’s disease who took the drugs, compared with 2.1 points in those who didn’t take them, according to the study published today.
A previous U.S. study of cardiovascular risk in the general population found that people taking ACE inhibitors were 60 percent less likely to be diagnosed with dementia, Molloy said. Other studies that focused on blood pressure haven’t found as much effect, Molloy said.
“The drugs we have for Alzheimer’s work for a year and they stop working,” Molloy said. “Many of these patients were on ACE inhibitors for years. The main thing is it’s continuing to work.”
It’s too early for doctors to prescribe ACE inhibitors to everyone at risk of dementia, Molloy said. People who already need treatment for cardiovascular disease such as high blood pressure and who are at risk of dementia may benefit if they take a centrally-acting ACE inhibitor, he said.
The effect could be due to the drugs acting against swelling in brain tissue or improving blood flow to the brain, Molloy said.