More On LDL & HDL

[Guest guest]

The problem with just looking at HDL-C as a single number or focusing on

it as a marker of risk reduction, is that it is not all HDL particles

act the same.

Some HDL particles protect against atherosclerosis but there are other

HDL particles that have been shown to atherogenic. The latter are found

more commonly in people consuming a lot of saturated fat and

cholesterol. There are also HDL particles that seem to have little

effect on atherosclerosis.

A recent large review was unable to demonstrate that changes in HDL

levels with drugs impacts the risk of CAD. Other research has shown a

drop in HDL as a result of eating a healthy low fat diet does not lower

the protective HDL particles that are involved in reverse cholesterol

transport or taking cholesterol from the periphery back to the liver.

So, low-fat diets may lower total HDL-C levels but do not impair reverse

cholesterol transport. So a high HDL-C level is no guarantee that

atherosclerosis will not progress. It depends not only on the total

amount of HDL-C but also on the type of HDL particles that make up that

total. In general apo A-1 levels are more predictive of a protective

effect than is the cholesterol content of all the HDL particles

combined. A lot of American women with HDL-C levels above 70 die of

heart attacks even when their LDLs are " normal " for Americans. Unlike

raising HDL-C levels using diet and/or drugs to lower LDL-C has

consistently been proven to slow, stop and even reverse atherosclerosis

and reduce heart attacks. So lowering LDL-C levels is often appropriate

for women who have multiple CAD risk factors like smoking, diabetes,

hypertension or clinical evidence of significant plaque.

So, in the study posted, I would be more concerned about the negative of

the LDL going up than the " proposed " positive of the HDL going up.