HDL To The Rescue

Doug asked me another question. And since, although I know little about ear wax, I do know a little more about waxy substances in blood, I decided to post it.

Q.   "Got back my lab tests this week. My cholesterol is a great 120 (thanks to drugs) but my HDL isn't high enough, apparently. Do you know if it matters that my HDL:LDL ratio is off, since my cholesterol is so low?"

A.   I'm not a doctor, it's just my opinion, but...

I would say, yes, it matters that your LDL/HDL ratio is low. It is more indicative of CHD (coronary heart disease) than total cholesterol (TC) alone.

HDL is good stuff. Someone can have a higher TC than you, but if their HDL is also high, they may deposit less cholesterol in their arteries since one of HDL's tasks is to scavenge cholesterol and return it to the liver. (Another beneficial effect of HDL is to slow the oxidation of LDL. See my last paragraph.)

You said that your "HDL isn't high enough". HDL as an absolute number, that is, not relative to total cholesterol (TC) or other fractions (like LDL) doesn't give you the whole picture. If your HDL is, say, 40 mg/dl (lowish), but it makes up a third of your 120 mg/dl TC, that's mighty fine - certainly better than if it made up a quarter or less of a higher TC.

Generally, it's good to see:
TC/HDL: 4 or less
LDL/HDL: 3 or less

Women's HDL tends to be higher than men's, at least before menopause. And while some female hormones (e.g. estrogen) bump it up, some male hormones (e.g. testosterone) push it down. So do smoking (including 2nd hand smoke), insufficient aerobic exercise, and other hormones (e.g. anabolic steroids).

All that said, the concern of late seems to be, apart from how much cholesterol you have, whether it's undergoing oxidation. That's key! It's not simply LDL, but oxidized LDL that promotes atherosclerosis. And it's inflammation that promotes oxidation. Did they test your CRP (C-reactive protein)? That's a marker for inflammation. You want that low. By the way, did I mention that omega-3 fatty acids, of the type commonly found in fish oil, reduce inflammation? I'd be lax if I didn't :)

When It Snows This Much

Instant Fort!

INTERHEART Study: Part 2

The more I read, the more flabbergasted I became. Maybe I'm just flabbergast-prone, but these nuances will give me a lot to jaw about over dinner tonight. Sorry, FRE*.

A continuation of my INTERHEART study post:

Smoking

Researchers found that smoking only 1 to 5 cigarettes a day increased the risk of heart attack by about 40%, a pack/day quadrupled the risk, and 2 packs a day increased the risk by a factor of 9 (900%). According to this graph, there is no threshold, or no point at which smoking more will not continue to increase risk. If there could be a bright side to this finding, it's that, if you smoke and are finding it difficult to quit, decreasing the number can at least decrease your risk proportionately.

Smoking was found to be such a powerful predictor of a heart attack that, according to Medscape, even if you puff on just 1 to 5 a day, "it could eliminate as much as 75% of the benefit of taking a statin." That's like throwing money out the window. Actually, it's like making tobacco and pharmaceutical companies richer at the expense of a few years of your life.


Combining Risk Factors

From the study:

"Incorporation of all nine independent risk factors (current or former smoking, history of diabetes or hypertension, abdominal obesity, combined psychosocial stressors, irregular consumption of fruits and vegetables, no alcohol intake, avoidance of any regular exercise, and raised plasma lipids) indicates an odds ratio of 129•20. [Using the extremes] increases the combined effect of all nine risk factors to 333•7."

So, if your only vice was to smoke a pack of cigarettes a day, your heart attack risk might be 4 times greater than if you didn't smoke. But smoke, shun fruit/vegs, shun exercise, carry a midsection, suffer high blood pressure, etc., and you could be 334 times (33,370%) more likely to experience heart failure. That's mighty predictive if you ask me.


Family History

This one surprised me. I thought genes would play a larger role. According to INTERHEART, 90.4% of heart attacks can be attributed to one of the 9 factors mentioned; that rises to only 91.4% when you factor in family history. So you may be born with a predisposition, but how you live your life will ultimately govern your heart health.


BMI vs. Waist-to-Hip

These are 2 popular anthropometric measurements used in nutrition. I never thought BMI (Body Mass Index) would catch on, but I hear "I'm down to 28, what's yours?" and "30!! Get out!!" more often. But BMI was never good at accounting for lean mass/fat mass or distribution of weight on a frame. A bodybuilder who is relatively short, albeit fat-free (not pictured), might meter in with a BMI of "morbidly obese". Maybe that's why BMI proved not as significant as the unglamorous waist-to-hip ratio in predicting a heart attack. If your waist measurement exceeds your hip measurement, it might not be a bad idea to stop reading right now and take the dog for a walk.

~~~~~~
Photo by Robert Browne.
* FRE: Fanatic's Resident Eater

Heart Attack: A Choice? (INTERHEART Study)

While researching an alternative therapy for cholesterol reduction (post to come), I stumbled upon this study in the Lancet (requires free registration):

Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study)

It's not breaking news, in fact it's over a year old. And the gist isn't anything you couldn't conjure in your sleep. What struck me was the breadth of it, in both number of subjects and variety of population. It included almost 30,000 people from 52 countries - men and women, young and old, from every inhabited continent, representing almost every racial and ethnic group on the planet.

What's stunning is their implication that over 90% of heart attacks worldwide are preventable. Prior to this it was thought that 50% of heart attacks were caused by some combination of the 9 modifiable risk factors in this study, and the remaining 50% were caused by unexplained phenomenon - maybe something in the environment, maybe an inborn error of metabolism, who knows.

Now we know. Here are the 9 risk factors that the INTERHEART study claimed were responsible for over 90% of heart attacks:


Each of these risk factors was found, by itself, to be predictive of heart failure.

Here are a few notes about the above table:

1. PAR is the Population Attributable Risk. Note the combined PAR of 90.4 - meaning, when all factors were analyzed together, they accounted for 90.4% of the risk for heart attack in this population.
   
2. The Odds Ratio (OR) is the probability or odds of an event (heart attack) occurring when exposured to a given risk factor, compared to a control. An OR of less than 1 indicates a protective effect.
   
3. Regarding that cholesterol measure: ApoB, or apolipoprotein B, is a type of protein found in LDL (and other non-HDL cholesterol carriers), and has come to be regarded as more predictive of atherosclerosis than the LDL measurement alone. ApoA1, or apolipoprotein A1, is a type of protein found in HDL. ApoB/ApoA1 may replace LDL/HDL in the future.
   
4. The smoking factor included "individuals who smoked any tobacco in the previous 12 months." So, your risk is still pretty high if you quit less than a year ago.
   
5. Psychosocial factors included measures of depression, stress at work or home, financial stress, stressful life events, and feeling of control. Why this one didn't rank first is beyond me.
   
6. Abdominal obesity is indicated by a high waist-to-hip ratio.
   
7. Hypertension = chronic high blood pressure.
   
8. The PAR for diabetes (risk attributable to diabetes) would probably be much higher if there weren't so many undiagnosed cases worldwide. The same is true for the hypertension PAR, especially since they used self-reported figures.
   
9. The above figures were adjusted for age, sex, smoking, and all other risk factors.

Each region and ethnic group had its unique risk list, and men scored differently from women, young from old, etc. But when all were grouped together, the top 2 factors - responsible for about 2/3's of all heart attacks - were smoking and unhealthy cholesterol levels.

Every one of these 9 factors is, by and large, within our control. But a claim that might be drawn from these findings - that heart attacks are a result of choices we make - is a claim no cardiovascular disease patient wants to hear, nor one an adroit healthcare professional is likely to share with you - not after the fact, anyway.

Dr. Jean-Pierre Després, a discussant at the presentation of the INTERHEART research, expressed his personal outrage: "Mankind is doing a good job of killing itself."