Infections
Dear Dr. Mirkin: How does inflammation
cause heart attacks?
When germs get into your bloodstream, you are
supposed to produce white blood cells and antibodies that help
kill these germs. The white blood cells produce chemicals that
cause swelling to bring fluid to carry body defense mechanisms,
and other chemicals to call out other cells that increase swelling,
redness and pain. So inflammation is good because it helps to
protect you from infection. However, if you allow the
inflammation to continue, or if your produce inflammation when
you don't need it, swelling damages your tissues and you may
suffer heart attacks, strokes, cancers, Crohn's disease, psoriasis,
arthritis, or even Alzheimer's disease.
A study in The New England Journal of Medicine
(November 2002) showed that women with high levels of a blood
test called C reactive protein (CRP), which measures
inflammation, are twice as likely as those with high cholesterol to
die from heart attacks and strokes. This study followed 28,000
women for eight years. Dr. Paul Ridker of Brigham and Women's
Hospital in Boston found that CRP did a better job of predicting
heart disease risk than cholesterol, which tells us that
inflammation is more important than blood fat levels in predicting
heart attacks. The fatty plaque buildup that lines blood vessels
often becomes inflamed because your white blood cells attack
your own tissue rather than just germs. Fat cells are also known
to turn out these inflammatory proteins. Other causes of
inflammation include high blood pressure, smoking, obesity, and
lingering low-level infections such as chronic gum disease.
Inflammation is thought to weaken the fatty buildups, or plaques,
making them more likely to burst. A piece of plaque can then
lead to a clot that can choke off the blood flow and cause a heart
attack.