- Common respiratory and urinary tract infections play
a role in triggering heart attacks and strokes, a study of 40,000 medical
records suggests.
-
- Infections such as bronchitis, pneumonia and cystitis
raised the risk of a heart attack fivefold, and of a stroke threefold,
for the period a patient was ill.
-
- The blame has been pinned on inflammation caused by the
infections.
-
- The research, funded by several leading research bodies,
is published in the New England Journal of Medicine.
-
- Scientists discovered the risk of heart attack and stroke
was substantially higher in the three days after a respiratory tract
infection.
-
- The likelihood of having either then decreased gradually
over the following weeks.
-
- Researcher Professor Patrick Vallance, of University
College London, said the work showed the timing of a heart attack was not
always random.
-
- He told the BBC News website: "After the age of
50, we all have some degree of furring up of the arteries, but most of
the time it sits there fairly harmlessly.
-
- "However, during infection stable deposits become
unstable and may break off, causing the blockages that may lead to a heart
attack or a stroke."
-
- Changing risk
-
- Professor Vallance said the idea that a patient's risk
was constant was misleading. In fact, the risk fluctuated all the
time.
-
- He said the latest study suggested that extra care should
be given to patients who were likely to be experiencing an inflammatory
response - for instance those who were undergoing abdominal surgery.
-
- Dr Liam Smeeth, lead researcher on the project, said:
"This knowledge will open up new avenues for research and
discovery.
-
- "Armed with the information we have found, we can
begin to develop new strategies to reduce the occurrence of heart attacks
and strokes."
-
- The team also investigated whether vaccinations,
including
flu and tetanus, increased the risk of heart attacks or strokes. They found
no heightened risk.
-
- Dr Douglas Fleming, from the Royal College of GPs, said:
"It has always been the case that December is the key month for
increased
cases of bronchitis - particularly in children and the elderly.
-
- "There has been a lot of argument on whether
infections
may precipitate heart attacks and it is true that, looking at the figures,
the risk is slightly increased - but I would stress this is only a slight
increase and patients should not be unduly worried."
-
- He added: "As a rule, patients with slight
bronchitis
do not need to see their GP, however if their bronchitis is a problem then
they should make an appointment.
-
- "If a patient has a history of heart disease and
the weather is particularly cold then they should try to stay
indoors."
-
- The study was funded by the British Heart Foundation,
the Medical Research Council and the Wellcome Trust.
-
- © BBC MMIV
-
- http://news.bbc.co.uk/2/hi/health/4095033.stm
|
