The well-being of your arteries depends on a healthy
endothelium, the inner lining of your blood vessels. “Endothelial cells are the
prima donnas within the blood vessels. They control almost every activity that
occurs in the vessels, and they’re fundamentally altered with age,” Dr. Lakatta
says. “People who maintain a healthy endothelium as they get older and those
who make an effort to do things that promote the repair of injured endothelium can
reduce the risk of heart attacks and strokes caused by atherosclerosis or
hypertension.”
Although scientists still have much to learn about the
endothelium and what can be done to keep it healthy, a number of studies
suggest that certain modifiable risk factors can have an important impact on
the cardiovascular system. For instance, regular moderate exercise, such as
running, walking, or swimming can reduce body fat, increase lean muscle mass,
decrease blood pressure, increase HDL cholesterol (the “good” cholesterol)
levels, and lessen the extent of arterial stiffening. All of these
exercise-induced changes can have a positive influence on endothelial cells.
In addition, scientists have long known that tobacco smoke
contains numerous toxic compounds, such as carbon monoxide, that promote
endothelial cell damage. Smoking also increases blood pressure and heart rate.
Free radicals in smoke slash the amount of nitric oxide available in the blood stream.
Nitric oxide, as you may recall, is a signaling molecule that helps keep
arteries pliable. Because nicotine causes narrowing of blood vessels, less oxygen
is transported to the heart. If you smoke, blood platelets become stickier and
are more apt to form clots in your arteries.
As we mentioned earlier, high blood pressure, hypertension, causes
blood vessels to thicken, diminishes production of nitric oxide, promotes blood
clotting, and contributes to the development of atherosclerotic plaques in the
arteries. Blood pressure is considered high when systolic pressure exceeds 140
mmHg and when diastolic blood pressure is higher than 90mmHg.
Excessive weight increases the risk of high blood pressure
and can increase the likelihood that you’ll have high blood triglycerides and
low HDL cholesterol, Dr. Lakatta says. Being overweight can also increase the
probability you’ll develop insulin resistance, a precursor of diabetes.
Diabetes, a disease in which the body does not produce or
properly use insulin, becomes more common as we age. In fact, nearly half of
all cases are diagnosed after age 55. Atherosclerosis develops earlier and is
more aggressive in people who have diabetes. In part, this occurs because
diabetes causes the endothelium to produce excessive amounts of superoxide
anion, a free radical that destroys nitric oxide. People age 65 and older who have
diabetes are nearly four times more likely than those who don’t to develop
peripheral vascular disease, a condition that clogs the arteries that carry
blood to the legs or arms. And, cardiovascular diseases and stroke are leading
causes of diabetesrelated deaths. If you suspect you have or are at risk for
diabetes, check with your doctor. Symptoms include increased thirst, increased hunger, fatigue, increased urination — especially
at night, unexplained weight loss,
blurred vision, and slow healing of wounds and sores.
Researchers have also found that stress reduction techniques, such as taking a walk,
practicing yoga, or deep breathing are important to cardiovascular health.
Emotional stress triggers the release of adrenaline from the adrenal gland and
noradrenaline from the nerve endings in your heart and blood vessels. These
hormones make the heart beat faster and adversely affect blood vessels. Under stress,
an older person’s blood pressure rises more rapidly and stays higher longer
than a younger person’s because the older person’s blood vessels are stiffer
and have lost much of their elasticity.
(From ‘Aging Hearts and Arteries, a
Scientific Quest’, a publication of US National Institute of Health)
