Tuesday, September 11, 2007

The dangers of low HDL

High density lipoprotein (HDL) is a carrier protein that takes cholesterol out of tissues such as your blood vessel walls (where you do NOT want it) and carts it back to the liver for elimination. Low density lipoprotein, on the other hand, carries cholesterol from the liver where it has been manufactured or the gut where it has been absorbed from dietary sources and moves it out to the cells. Some cholesterol is essential to life (we make cellular membranes and hormones out of it for example), but too much in the wrong place can lead to an unwanted build-up of fatty schmutz in the arteries.

The 'my oh my will you look at that low LDL' attitude that caused us doctors to beam at you patients is starting to change. A study out of the Palo Alto VA medical Center* emphasizes the importance of HDL levels to cardiovascular health.

Researchers there retrospectively studied the old vets (average age 65) to correlate HDL levels with the incidence of hospitalization for ischemic heart disease including heart attack. All of the 6,357 subjects had an enviable LDL level below 60 mg/dl.

Those patients in the lowest HDL quartile with HDL levels of 28 or below had a 1-year incidence of ischemic heart related troubles of 8.5% compared with those in the top HDL quartile whose HDL levels were 64 or above.

Too bad its currently very difficult to boost HDL levels. Clinical trials of Pfizer's HDL-raising torcetrapib were abruptly halted at the end of last year due to a pesky 60% increased risk of death in the groups receiving the drug plus Lipitor compared to those on Lipitor alone. Meanwhile, weight loss, exercise, and a whiff of alcohol as part of a healthy lifestyle are helpful in nudging HDL levels upward.
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deGoma, EM. Presentation at the annual session of the American Heart Association

10 comments:

KGMom said...

I am confused. I have to read this again to understand.
So having a high LDL number may not be so bad.
I need to know this--I see my family doc soon, and I want to be ready to tell her--oh no, it's ok if my LDL is up a bit.

Femail doc said...

KGM: My point in all this is that the risk of HDL cholesterol is independent of the risk of high LDL. So even though your LDL is reassuringly low, an HDL-cholesterol level that was also low (less than 40) increases risk. Conversely, if your LDL is 'up a bit,' a high HDL would decrease overall risk.

KGMom said...

Got it.
My LDL number is usually pretty low, and my HDL number is up--that's good.

Mauigirl said...

I know they often look at the ratio of HDL to LDL as part of the equation as well, which would also be a better ratio when HDL is high; but if LDL were particularly low, then the ratio might be good but if HDL is lower than desirable anyway, then it is still a concern. So this is interesting new information.

Anonymous said...

Hi,

My son (17.8) has a total Cholesterol of 108 (which the lab said was low out of range) and a low HDL level of 27. The others were within range Tri=75, VLDL=15, LDL=66,Total to HDL=4.0, LDL/HDL=2.44.

My question is that I am reading that this is actually not okay. I'm not sure if I should insist to his pedi that we do further testing, and if so, WHAT? I'm not sure if I should be worried, or not concerned.

(I tried to send this with my log in but I can't get it to work so I had to do it anonymous. If you'd like, feel free to e-mail me at LuvBeingMommyTo3@aol.com)

DeAnn said...

I just got my blood test results and my LDL went from 108 in February to 94 in August, which the nurse said was good. But my HDL went from 37 to 26. I had really upped my exercise between the two blood tests, and so I thought the HDL would go up. Why didn't exercise help? What can I do to raise my HDL? I had joined Weight Watchers 3 months ago and lost 17 pounds. Does weight loss lower HDL?

worriedgirl said...

i turned 21 one sep. 30th but my blood work was done when i was 20 at the heathest time of a persons live my HDL was 28 and i am a girl what can i do?

worriedgirl said...

if no one is going to answer then i am leaving and never coming back listing a sight about how there not dependent realy aint that helpful i knew that and i havent takin a single medical class

worriedgirl said...

by the way if your thinking 'oh she's 21 she must be going out geting drunk and doing drugs to lower her HDL. no i have never been high or drunk the closest i came to that is when i had surgery
bye

femail doc said...

Dear Worriedgirl, I would never assume that anyone 21 or otherwise was drinking or doing drugs.

You haven't mentioned your other cholesterol numbers which would be helpful to figure out your overall cardiac risk. In addition, a very important piece of information would be whether or not one of your parents or siblings had a heart attack or other heart problems at an early age (less than 45 years for males and less than 55 for females). Since you're so young, you might also include any info about grandparents and their heart health history as they grew older.

HDL levels are hard to change. Losing weight if you are overweight might help, as would vigorous exercise on a daily basis of the kind that makes you hot, sweaty, and out of breath. A little bit of alcohol (one drink a day) has been shown to slightly increase HDL, although if you do not drink I would not advise you to start now just to affect your HDL level.

If you would like, my personal e-mail is on the sidebar here, so you can send me the info by e-mail. If you don't mind posting in the comment section, however, your story might be helpful to other worried girls.