11. August 2006 William Davis (0)
The recognition of the metabolic syndrome as a distinct collection of factors that raise heart disease risk has been a great step forward in helping us understand many of the causes behind heart disease.

Curiously, there's not complete agreement on precisely how to define metabolic syndrome. The American Heart Association and the National Heart, Lung, and Blood Institute issued a concensus statement in 2005 that "defined" metabolic syndrome as anyone having any 3 of the 5 following signs:





Waist size 40 inches or greater in men; 35 inches or greater in women

Triglycerides 150 mg/dL or greater (or treatment for high triglycerides)

HDL-C <40 mg/dL in men; <50 mg/dL in women (or treatment for reduced HDL-C)

Blood Pressure >130 mmHg systolic; or >85 mmHg diastolic (or drug treatment for hypertension)

Glucose (fasting) >100 mg/dL (or drug treatment for elevated glucose)


Using this definition, it has become clear that meeting these criteria triple your risk of heart attack.

But can you have the risk of metabolic syndrome even without meeting the criteria? What if your waste size (male) is, 36 inches, not the 40 inches required to meet that criterion; and your triglycerides are 160, but you meet none of the other requirements?

In our experience, you certainly can carry the same risk. Why? The crude criteria developed for the primary practitioner tries to employ pedestrian, everyday measures.

We see people every day who do not meet the criteria of the metabolic syndrome yet have hidden factors that still confer the same risk. This includes small LDL; a lack of healthy large HDL despite a normal total HDL; postprandial IDL; exercise-induced high blood pressure; and inflammation. These are all associated with the metabolic syndrome, too, but they are not part of the standard definition.

I take issue in particular with the waist requirement. This one measure has, in fact, gotten lots of press lately. Some people have even claimed that waist size is the only requirement necessary to diagnose metabolic syndrome.

Our experience is that features of the metabolic syndrome can occur at any waist size, though it increases in likelihood and severity the larger the waist size. I have seen hundreds of instances in which waist size was 32-38 inches in a male, far less than 35 inches in a female, yet small LDL is wildly out of control, IDL is sky high, and C-reactive protein is markedly increased. These people obtain substantial risk from these patterns, though they don't meet the standard definition.

To me, having to meet the waist requirement for recogition of metabolic syndrome is like finally accepting that you have breast cancer when you feel the two-inch mass in your breast--it's too late.

Recognize that the standard definition when you seen it is a crude tool meant for broad consumption. You and I can do far better.
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Your heart scan is just a "false positive"

Your heart scan is just a "false positive"

15. August 2006 William Davis (0)
I've seen this happen many times. Despite the great media exposure and the growing acceptance of my colleagues, heart scans still trigger wrong advice. I had another example in the office today.

Henry got a CT heart scan in 2004. His score: 574. In his mid-50s, this placed him in the 90th percentile, with a heart attack risk of 4% per year. Henry was advised to see a cardiologist.

The cardiologist advised Henry, "Oh, that's just a 'false positive'. It's not true. You don't have any heart disease. Sometimes calcium just accumulates on the outside of the arteries and gives you these misleading tests. I wish they'd stop doing them." He then proceeded to advise Henry that he needed a nuclear stress test every two years ($4000 each time, by the way). No attempt was made to question why his heart scan score was high, since the entire process was outright dismissed as nonsense.

I'm still shocked when I hear this, despite having heard these inane responses for the past decade. Of course, Henry's heart scan was not a false positive, it was a completely true positive. I'm grateful that nothing bad happened to Henry through two years of negligence, though his heart scan score is likely around 970, given the expected, untreated rate of increase of 30%.

The cardiologist did a grave disservice to Henry: He misled him due to his ignorance and lack of understanding. I wish Henry had asked the cardiologist whether he had read any of the thousands of studies now available validating CT heart scans. I doubt he's bothered to read more than the title. The cardiologist is lucky (as is Henry) that nothing bad happened in those two years.

Do false positives occur as the cardiologist suggested? They do, but they're very rare. There's a rare phenomenon of "medial calcification" that occurs in smokers and others, but it is quite unusual. >99% of the time, coronary calcium means you have coronary plaque--even if the doctor is too poorly informed to recognize it.
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