UK researchers showed that ARBs and ACE inhibitors show a stronger association with Alzheimer's disease and other dementias than other BP drugs.

Why was this link examined?
Angiotensin signalling has been shown to be involved in the development of Alzheimer's disease.

To study this link further, Professor Patrick Kehoe and colleagues used the general practice research database to find cases of dementia in people over 60 years old. They found data on 5,797 cases of Alzheimer's disease, 2,186 of vascular dementia and 1,214 of other dementias.

Each of these cases was matched to up to four controls by age, practice and gender.

The researchers found that patients diagnosed with Alzheimer's disease, vascular and other dementias had been given fewer prescriptions for ARBs and ACE inhibitors. ARBs were associated with a 53 per cent lower risk of developing Alzheimer's disease, while ACE inhibitors were associated with a 24 per cent lower risk.

Could this lead to treatments?
Professor Kehoe and his team said the findings 'could provide significant patient and socio-economic benefits if these data reflect a true causal effect'.

But they said further evidence from randomised trials would be needed to show whether their findings are causal or reflect some form of bias. 'Such studies should examine both secondary prevention of mild cognitive impairment to dementia as well as tertiary prevention for patients with newly diagnosed Alzheimer's disease,' they said.

Dr Simon Ridley, head of research at Alzheimer's Research UK, pointed out that high BP is already a known risk factor for dementia. 'This study highlights the potential for particular BP drugs to help with Alzheimer's disease,' he said.

'If these findings can be supported in clinical trials, this could be an important step forward.'

Informing patients
Case-control research suggests ARBs are linked to a halving of Alzheimer's disease risk. ACE inhibitors were also associated with a 24 per cent lower risk. Clinical trials will be needed to see whether BP drugs can reduce Alzheimer's risk.