More than 30
years ago, when Dr. David Heber was an intern at Beth
Israel Deaconess Medical Center, he asked the senior
doctors the same question over and over.
"How come all
my patients have high blood pressure, high cholesterol
and diabetes? Are these things linked?" His
mentors would shrug and say, "Dave, common things occur
commonly. Go back to work," he said.
Today,
doctors know Heber’s intuition was right. Type 2
diabetes and heart disease are physiologically linked.
What’s more, according to new government figures, a
whopping 64 million Americans now have what's called
Metabolic Syndrome [cq caps], also known as insulin
resistance, which doubles the risk of heart disease and
raises diabetes risk by 30 percent.
"It’s a chain
from obesity to diabetes to heart disease," said Heber,
now director of UCLA’s Center for Human Nutrition. "In
the next 10 years, 80 percent of all heart disease will
be due to Type 2 diabetes."
Granted, you
may never have heard of Metabolic Syndrome. But you
probably have it if you have any three of the following
five factors:
§
Abdominal
obesity, as gauged by a waist circumference of 40 inches
or more for men, 35 for women.
§
Elevated
triglycerides (150 milligrams per deciliter or more)
§
Low HDL or
"good" cholesterol (less than 40 mg/dl in men, 50 in
women)
§
High blood
pressure (130 millimeters of mercury or higher, over 85
mm or more)
§
Moderately
elevated fasting blood sugar (110 mg/dl to 125 mg/dl).
The pace at
which Americans, especially women, are falling prey to
this nasty cluster of symptoms is increasing shockingly
fast.
In this
month’s [October] issue of Diabetes Care, researchers
from the federal Centers for Disease Control and
Prevention said that between one study done from 1988
through 1994 and another done in 1999-2000, there was "a
significant increase" in the prevalence of the metabolic
syndrome in adults aged 20 and older.
But while the
rise in metabolic syndrome among men was relatively
small, 2.2 percent, among women it was 23.5 percent,
driven in large part by rising obesity. In recent years,
tens of millions of female Baby Boomers have been going
through menopause, which typically leads to an upper
body weight gain of 12 to 20 pounds.
While heart
disease does not cause diabetes, diabetes -- or insulin
resistance -- can lead to heart disease. Having
diabetes,
"is the equivalent of already having had a heart attack
in terms of the risk of having a new heart attack," said
Dr. Edward S. Horton, vice president and director of
clinical research at the Joslin Diabetes Center.
Metabolic
Syndrome "is not a disease per se,"
said Dr. Paul Ridker, director of the center for cardiovascular
disease prevention at Brigham and Women’s Hospital,
.
but "it is an important warning sign that something has to be
done." The term hammers home the point that heart
disease and diabetes, "while seemingly different, share
a common soil."
But metabolic
syndrome is still treated piecemeal, as a bunch of
symptoms, rather than one, linked problem.
Doctors
use separate drugs to control blood pressure,
cholesterol and triglycerides. Drugs approved to treat
diabetes are not yet approved for metabolic syndrome --
though trials to gauge their usefulness for this are
underway.
The far
better approach to treating the overall problem, Ridker
and others said, is the hard, low-tech way: by losing
weight through diet and exercise.
The good news
is "you don’t have to lose a ton of weight to partially
reverse Metabolic Syndrome," said Dr. Richard Nesto,
Chairman of the Department of Cardiovascular Medicine at
the Lahey Clinic and one of the country’s foremost
experts on the overlap between heart disease and
diabetes.
"You only
have to lose 12 to 16 pounds to see marked improvement
in cholesterol, blood pressure and CRP," or C-reactive
protein, a marker of inflammation that some doctors
believe should be part of the definition of Metabolic
Syndrome. The reason losing weight is so crucial, as
opposed to fighting symptoms one by one, is that stored
fat in the abdomen -- not the subcutaneous blubber you
can grab with your hands, but the deep fat that wraps
itself around internal organs -- pumps out chemicals
that drive both Type 2 diabetes and heart disease.
So-called visceral fat is a biologically active organ.
"It’s a little factory in the belly that makes bad
hormones," as Nesto put it.
Here’s what
scientists think is going on. Stored fat makes
inflammatory chemicals called cytokines, which trigger
inflammation all over the body, including in blood
vessel walls. Cytokines also raise CRP, which in turn
raises the risk of heart disease, even in people with
normal cholesterol. Cytokines also increase the tendency
for blood to clot, triggering potentially fatal heart
attacks. They also raise blood pressure and worsen
cholesterol profiles. And they cause
narrowing of arteries, including those that feed the heart
and other vital organs.
Just as
important, cytokines from fat also mess up the delicate
system by which insulin, the hormone that escorts sugar
into cells, sends its chemical signals inside cells.
Faulty insulin signaling in turn triggers insulin
resistance, which forces the pancreas (which makes
insulin) to work harder and harder until it finally
gives out, creating full-blown diabetes.
Meanwhile,
fat cells also release free fatty acids, which flock to
the liver, where they are linked together into little
bundles (triglycerides) and pumped back into the blood.
In high enough amounts, these triglycerides disrupt
cholesterol balance, making levels of "good" (HDL)
cholesterol fall.
"Fatty acids
are also toxic in themselves," said Dr. George L.
Blackburn, associate director of nutrition in the
Division of Nutrition at Harvard Medical School.
All in all,
not a pretty picture. You can take statin drugs like
Lipitor or Zocor to lower "bad" or LDL cholesterol and
reduce C-reactive protein levels. You can take
diuretics, ACE-inhibitors or other drugs, to lower blood
pressure. You can take Lopid or Tricor to lower
triglycerides and Niaspan to boost "good" cholesterol.
You can also
take some drugs that are approved for diabetes but not
yet for insulin resistance, among them Glucophage,
Avandia and Actos.
But the best
solution, is to take an ordinary tape measure and
measure your waistline. If your girth is too great, get
serious about losing weight.
Judy Foreman’s
column appears every other week. Past columns are available on
www.myhealthsense.com.