Blood pressure drugs, aging and diabetes

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From:

http://www.newscientist.com/news/news.jsp?id=ns99992866

10:45 03 October 02

Exclusive from New Scientist Print Edition

Common blood-pressure drugs that help prevent the life-threatening

complications of diabetes may do so by slowing the accelerated ageing from

which diabetics suffer. The discovery could one day lead to drugs that delay

some of the symptoms of ageing in everyone.

People with diabetes tend to age rapidly, particularly if they have type 1

diabetes, which strikes in childhood. Those with the condition often go

blind, and they suffer from heart and kidney disease and high blood pressure

far earlier than normal. Their skin can wrinkle in their twenties.

" The rule of thumb is that people look as old as their chronological age

plus the duration of their diabetes, " says team member Merlin of the

Baker Medical Research Institute in Melbourne.

That ageing occurs partly because high blood-sugar levels encourage the body

to produce gluey sugar-protein complexes called advanced glycation end

products. AGEs interfere with some cell functions and make tissues such as

blood vessels stiffer. In healthy people, AGEs form far more slowly.

The Australian team, led by Mark of the Baker Institute, has found

that a common blood-pressure drug called ramipril stops the build-up of AGEs

in rats with diabetes. Those rats also had far less damage to their kidneys.

" There was complete prevention, " says team member phine Forbes. The

results will appear in November's issue of the journal Diabetes.

Unpleasant side-effects

Ramipril is a type of blood-pressure drug called an ACE inhibitor, and

diabetic patients who take ACE inhibitors are known to suffer less kidney

and heart disease than those taking other types of blood-pressure drugs. But

until now the reason has not been clear.

ACE inhibitors reduce blood pressure by blocking the formation of

angiotensin II, a protein that makes blood vessels constrict. Evidence is

building that angiotensin II also increases oxidative stress, creating free

radicals that in turn stimulate production of AGEs.

's team is now measuring AGEs in the blood of people with diabetes who

take ACE inhibitors to find out whether their AGE levels are lower. The team

is also testing different types of AGEs to see which ones cause the

problems. The next step will be to find inhibitors that target these AGEs.

And it is not just people with diabetes who may reap the benefits of drugs

designed to cut AGE levels. Many experts believe the build-up of AGEs helps

cause kidney disease and glaucoma as well as the narrowing of the blood

vessels in cardiovascular disease and the formation of brain plaques in

Alzheimer's. AGEs also accumulate in the skin, helping make it wrinkly.

ACE inhibitors are unlikely to become an elixir of youth because they cause

unpleasant side effects such as coughing and irregular heartbeat. But future

drugs designed to block AGEs might have fewer side effects.