Postprandial triglycerides - a major diabetic CVD risk factor:
Many type 2 diabetics have extremely high lipid (triglyceride) levels,
particularly after eating fatty meals (postprandial). A number of recent
studies have shown that diabetic postprandial lipemia is a major cardiovascular
risk factor.
Postprandial
triglyceride levels in type 2 diabetics
Triglycerides remain elevated in type
2 diabetics long after eating.
Flow chart showing the
progression of atherosclerosis in type 2 diabetes.
Figure 1:
Tanaka, J. Atheroscler Thromb, 2004; 11:322-329E
Figure 2:
Tushuizen, Postgrad Med J 2005;81:1–6
Postprandial triglycerides are packaged into large
lipoproteins called chylomicrons. These scatter light, and give
lipemic plasma its characteristic milky color. As it turns out, this
turbidity correlates well with both triglyceride levels and levels of
postprandial lipemia. In the photo below, the chylomicrons are the
large particles on the upper left. Note their large size relative to the
VLDL, LDL, and HDL particles.
In type 2 diabetes, the chylomicrons circulate in the
bloodstream in excessive amounts after fatty meals. The chylomicrons are
broken down into smaller, more-dangerous lipoproteins such as small LDL,
which adhere to the linings of arteries, causing atherosclerosis. The
resulting fatty build-up causes damage to the lining of the artery,
leading to atherosclerosis, coronary artery disease, and other types of
cardiovascular disease
Postprandial triglycerides circulate as large
chylomicron particles, which degrade to more dangerous small-LDL
reminants.
The small-LDL reminants adhere to artery linings,
stimulating an inflamitory reaction that leads to atherosclerosis.
The problem is that postprandial lipemia is invisible to
both diabetics and their physicians. Physicians don't detect postprandial
lipemia because the standard lipid panel only tests fasting
triglycerides. Patients don't detect postprandial lipemia because it
generates no symptoms, and is presently undetected by blood glucose tests,
which the diabetic typically performs several times a day. Since the
problem is largely invisible, postprandial lipemia is almost always
untreated, contributing to the gradual onset of cardiovascular disease.
Therapeutic options exist that can reduce lipemia: A large number of different therapeutic, dietary, and exercise regimens
are effective at decreasing the extent of postprandial lipemia and the risk of
cardiovascular disease. Therapeutic regimens include statins, fibric acid
derivatives, bile acid sequestrants, nicotinic acid, and hormone replacement
therapy. Dietary regimens include use of omega-3 fatty acids (common in flax and
fish oil), avoidance of high fat diets, and proper choice of dietary fats.
Exercise and weight loss also reduce postprandial lipemia.
To correct it, you must detect it:
Ideally, what is needed is a next-generation blood glucose monitor that is just
as inexpensive and easy to use as current blood glucose monitors, but which
gives a lipemia measurement as well as the blood glucose measurement. Current
blood glucose monitors already have timekeeping capability, memory, and onboard
data management, which give the patient a historical perspective of how their
glucose measurement fluctuates throughout a day. If these meters did the same
thing for lipemia as well, then postprandial lipemia issues would be quickly
revealed, and the patients could then take steps to address this issue.
