Longer term effects of dementia drugs to be investigated

A £50,000 grant from the Alzheimer's Research Trust will look at whether ACE inhibitors used to treat Alzheimer's could have a longer term effect.

The two teams have received a £50,000 boost from the UK's leading dementia research charity, the Alzheimer's Research Trust, to look at whether blood pressure lowering drugs called Angiotensin-Converting Enzyme or ACE inhibitors also alter the build up of the protein amyloid which ‘clogs up' the brains of people with Alzheimer's disease.

The two-year project led by Dr Patrick Kehoe at the University of Bristol's Dementia Research Group and Dr Karen Horsburgh at the University of Edinburgh hopes to find out more about ACE inhibitors, a group of pharmaceuticals that are used primarily in the treatment of high blood pressure and congestive heart failure. Because lowering blood pressure has recently been shown to slow the rate of memory loss in people with early Alzheimer's, some experts hoped that ACE-inhibitors might be useful drugs for fighting the disease.

However, Dr Kehoe and Dr Horsburgh have concerns that while these drugs might be useful in the short term they could potentially worsen a person's Alzheimer's disease in the longer term because ACE, the enzyme that they inhibit, has been suggested to partly protect the brain from the toxic build up of amyloid. 

Dr Kehoe explains: "This work is really testing a theory and will try to clarify and if possible reconcile what appear to be slightly opposed theories in the field. On one hand some experts suggest these drugs may be helpful against Alzheimer's associated memory decline. On the other hand, the drugs theoretically might reduce the protection the brain naturally offers itself – so we really need to understand more about what is going on."

The scientists plan to assess the balance of benefit and risk by combining the Bristol Dementia Research Group's expertise in measuring the activity of the ACE enzyme, what it is doing in the brain and amyloid build up, with the Scottish group's expertise in experimental models of Alzheimer's disease to find out more. Together they hope to find out whether or not ACE-inhibitors increase the build up of amyloid compared to another group of drugs called Angiotensin Receptor Blockers or ARBs. If so, this second class of drugs might be a safer alternative for lowering the blood pressure of people with Alzheimer's disease.

Harriet Millward, Deputy Chief Executive of the Alzheimer's Research Trust, the UK's leading dementia research charity, said it is vital to understand more about the link between cardiovascular disease and Alzheimer's because both conditions are rising at a rapid rate in the UK. The number of people with Dementia is projected to double within a generation.

She said: "Alzheimer's is a complex and under-funded disease, so it is a real challenge to find the right treatments to fight it. If the researchers can find proof that one class of existing drugs has more benefits and fewer drawbacks than another then that is another big step forward – but we desperately need to fund many more steps if we are to beat this devastating disease and find a cure.

"We wish the two teams well in this exciting project. As a charity we're always delighted to fund studies that see scientists joining forces because we know that the next Alzheimer's breakthrough will only come if researchers work together."