The purpose of part one was to demonstrate the meaninglessness of calculated LDL cholesterol in relation to the equation used to calculated it, and how triglycerides, while being a very important risk factor for heart disease in its own right, have been steadily increasing on average and potentially giving a false sense of security as increases in triglycerides cause a mathematical (not necessarily biochemical) lowering of calculated LDL serum cholesterol.
I promised that in this second and final part, I will demolish the notion that you have any real idea of what your actual LDL cholesterol is, based on standard bloodwork involving calculated values. And I shall deliver.
Let me frame what I'm going to say this way: there are millions of people with low calculated LDL (say, <50-60) who are at infinitely more risk for atherosclerosis, rupture, and fatal heart attack than are many people with calculated LDLs in the high 200s and higher. If you eat significant amounts of carbohydrate, especially as processed food, have low HDL (<60), high triglycerides (>200), then it's essential to know exactly what your LDL really is. The standard blood panel is essentially worthless for this.
But I'm here to help. But first, let me show you what I mean by turning to Dr. William Davis, the cardiologist who originated Track Your Plaque and who blogs at The Heart Scan Blog. Dr. Davis, who used to practice by performing various coronary procedures such as installing stents, now spends his time detecting, preventing, and reversing heart disease.
He has lots of stories to tell. Let's get started.
Don't believe your LDL cholesterol!
"Harry's case is typical. For years, his doctor told him his LDL cholesterol of 123 mg was okay. But a heart scan score of 490 (90th percentile at age 52) made him question just where his coronary plaque came from.
"Lipoprotein analysis told a very different story: His LDL particle number was 2400 nmol, meaning his true LDL was more like 240 mg, nearly double the value of LDL obtained through his doctor. Harry had other sources of risk, too, but the LDL particle number was a clear stand-out. [...]
"...When LDL's are actually meaured, you find that LDL is rarely accurate. In fact, in our experience, inaccuracy of 30-50% is the rule, sometimes 100%. The one telltale hint that calculated LDL is wrong is when HDL is <50 mg -- that's nearly everybody. "
How accurate is LDL cholesterol?
"If there's so much attention paid to LDL, how accurate is it? 100%? 90%? 80%?
"Well, it varies widely. Occasionally, it's truly accurate, but most of the time it's miserably inaccurate. Every single day, I see people with LDL cholesterols that underestimates true (measured) LDL by 40%, 50%, and even over 100%. In other words, LDL cholesterol might be 120 mg/dl by the conventional method, but the genuine measured value might be 160 mg/dl, or even 240 mg/dl. It can be that far off -- and it's not rare.
"The converse can occasionally be true, though rarely in my experience: that conventional LDL overestimates true LDL. I saw someone in the office today like this, with a conventional LDL of 142 mg/dl but a true measured LDL of 115 mg/dl. I may see one or two more people like this the rest of this year."
When LDL is more than meets the eye
"I pointed out to Jerry that, given the low HDL and high triglycerides, his calculated LDL of 112 was likely inaccurate. In fact, if measured, LDL was probably more like 140-180 mg/dl. LDL particles were also virtually guaranteed to be small, since low HDL and small LDL usually go hand-in-hand (though small LDL can still occur with a good HDL).
"So Jerry's LDL is really much higher than it appears. To prove it, Jerry will require an additional test, preferably one in which LDL is measured, such as LDL particle number (NMR), apoprotein B, or "direct" LDL.
"It's really quite simple. Jerry likely has a high number of LDL particles that are too small. This pattern confers a three- to six-fold increased risk for heart disease."
The many faces of LDL
"Ginnie came in for an opinion about her heart scan score of 393. At age 57, this put her in the 99th percentile, a high score.
"LDL cholesterol: 96 mg/dl - This value puts Ginnie's LDL in the most favorable 25% in the country.
"LDL particle number: 2140 nmol/l - This value is in the worst 25% of the country and is the equivalent of an LDL cholesterol of 214 mg/dl (take off the zero).
"In addition, over 90% of Ginnie's LDL particles fell into the small class."
Making Dr. Friedewald an honest man
"Colleen started with the usual discrepancy between conventional calculated LDL cholesterol of 121 mg/dl and the far more accurate LDL particle number (NMR) of 1927 nmol/L. [...]
"In other words, by this simple manipulation, Colleen's Friedewald calculated LDL is off by 58%. This is very common, a phenomenon I witness several times every day.
"By LDL particle size, 75% of all Colleen's LDL particle were abnormally small (small LDL particle number 1440 nmol/L). This is a moderately severe small LDL tendency."
A Tale of Two LDL's
"Kurt, a 50-year old businessman with a heart scan score of 323, had a:
"--Conventional (calculated) LDL of 128 mg/dl - Real measured LDL 241 mg/dl.
"Laurie, a 53-year old woman who underwent a coronary bypass operation last year (before I met her), had a:
"--Conventional LDL of 142 mg/dl - Real measured LDL was 85 mg/dl.
"(By "real, measured" LDL, I'm referring to LDL particle number in units of nmol/L obtained through NMR lipoprotein testing and dividing by 10, or just dropping the last digit to convert the value to mg/dl. This technique was arrived at by comparing the population distributions of these two parameters, LDL particle number and calculated LDL. This is the gold standard in my view. Similar numbers can be obtained by measuring apoprotein B, direct LDL, or calculated non-HDL, with diminishing reliability from first to last.)
"In other words, Kurt's conventional LDL underestimated real LDL by 88%. Laurie's conventional LDL overestimated real LDL by 40%."
Had enough? Now do you see what I mean? I'll finish by quoting the heroic Dr. Davis once more from the last of those series of links.
Interestingly, Laurie's doctor had insisted she take Lipitor for a high LDL cholesterol. Her real LDL was, in fact, low to begin with and benefits of a statin drug would be little to none. (Remember, in our Track Your Plaque approach, multiple other treatments are included, such as omega-3 fatty acids from fish oil, vitamin D normalization, and wheat elimination, strategies that yield benefits that others expect to obtain with statins.) Laurie's real cause of her heart disease proved to have nothing to do with LDL cholesterol, but involved lipoprotein(a) and thyroid issues.
Kurt proved to have a severe preponderance of small LDL particles--the worst kind of LDL, while Laurie had none--a benign pattern.
Then how can anyone make sense of the conventional, calculated LDL cholesterol that is generally (95% of the time) provided? If accuracy can stretch to plus or minus 80% . . . you can't. Conventional LDL is a miserably inaccurate number. The problem is that obtaining a superior number requires a step or two more testing and insight, something most busy primary care doc's simply don't have in the midst of a day filled with arthritis, bronchitis, diarrhea, belly aches, and seborrhea.
Yet conventional--I call it "fictitious"--LDL serves as the basis for this $27 billion (annual revenues) industry selling statin drugs.
This is meant to be neither an argument in favor of nor against statin drugs. However, it is plain as day that any study designed to reduce LDL cholesterol will be hopelessly clouded by calculated LDL imprecision. A calculated LDL of, say, 143 mg/dl might really be 187 mg/dl, or it might be 74 mg/dl--you can't tell by looking just at LDL. Yet billions of dollars of research and billions of dollars of healthcare costs are based on the treatment of this number.
So, what's your LDL? Unless you've actually had it measured, you do not know. Neither does your doctor. Are you on medications or dietary prescriptions as a result of the fiction that you believe is your LDL? And how about particle size? Large & fluffy are actually good, while small and dense are very bad. You might have a low LDL, but with a high percentage of small and dense particles, and you could be at 6 or 10 times the risk as someone with an LDL of 250, but 99% large & fluffy. Don't be fooled by your doctor, HMO, hospital, or the drug companies.
And guess what will reduce your small and dense LDL every time? You guessed it: get off the grains, (particularly wheat), sugar, processed foods, processed vegetable oils; and take omega 3s and vitamin d to get your levels above 60.
How do you find out what your LDL actually is? Dr Davis says, "Our preferred method is NMR (LipoScience) LDL particle number, probably the most accurate of all. Second best: apoprotein B, direct measured LDL, and non-HDL."