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The ailment has many
names, including metabolic
syndrome, insulin resistance, Syndrome X, and the name I
will use,
prediabetes. Why
is it so easy to diagnose? There's one clue that's a dead giveaway:
It's your waistline. One of my colleagues says that when a patient's
belly is the first body part to enter his office, the diagnosis is
made. If you have gained weight in middle age and most of it is in
your belly, you are likely part of the epidemic of prediabetes. And
if you don't start eating better and exercising, full-blown diabetes
will almost certainly be in your future.
Why would a
cardiologist be so concerned with your waistline? The reason has
less to do with how you look on the
outside than it does with
how you look on the inside. I'm worried about what prediabetes and
diabetes are doing to your arteries. Both conditions can injure the
lining of your vessels and accelerate the production of plaque,
greatly increasing your risk of having a
heart attack or stroke.
After a meal, it is the
job of insulin to help transport fats as well as sugar from the
blood into the tissues. As you develop insulin resistance, fats
accumulate in your bloodstream and hang around much longer than
usual. During this time, changes in your blood fats occur — your LDL
particles and your HDL particles become smaller and your total HDL
is reduced. These changes favour the movement of cholesterol from
your bloodstream into your artery walls. The smaller and denser the
LDLs are, the more likely they are to move into your vessel walls.
And the smaller and denser the HDLs are, the less efficient they are
at removing the cholesterol from those vessel walls. These changes
are also associated with high blood fat levels measured in the form
of triglycerides. The fact that these fats are in your bloodstream
longer also favours their accumulation in the vessel walls.
So, if you have gained
predominantly belly fat as an adult and there is diabetes in your
family (even if it occurred in a parent or grandparent late in
life), you probably are insulin resistant and have prediabetes. The
diagnosis of prediabetes is made if you meet three of the five
following criteria:
Central obesity:
A waist circumference of greater than 101cm for men and 85cm for
women
Elevated triglycerides:
Greater than or equal to 150 mg/dL
Low
total HDL:
Less than or equal to 40 mg/dL for men and less than or equal to 50
mg/dL for women
Elevated blood pressure:
Systolic blood pressure of greater than or equal to 130 mm Hg and
diastolic blood pressure of greater than or equal to 85 mm Hg
Elevated fasting glucose:
Greater than or equal to 100 mg/dL
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