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Old Sat, Jun-27-09, 20:15
Nancy LC's Avatar
Nancy LC Nancy LC is offline
Posts: 45,396
Plan: Paleo 99.5%
Stats: 210/170/160 Female 67.5"
Progress: 80%
Location: San Diego, CA

Here's another article on the failure of the calculated LDL test on low carbers:

When Friedewald Attacks And the cool part is it offers an alternative calculation when your triglycerides are below 100.

When you walk into the doctor's office and ask him to measure your cholesterol, the numbers you get back will generally be total cholesterol, LDL, HDL and triglycerides. All of those except LDL are measured directly. LDL is calculated using the Friedewald equation, which is (in mg/dL):

LDL = TC - HDL - (TG/5)

Low-carb advocates have known for quite some time that this equation fails to accurately predict LDL concentration outside certain triglyceride ranges. Dr. Michael Eades put up a post about this recently, and Richard Nikoley has written about it before as well. The reason low-carb advocates know this is that reducing carbohydrate generally reduces triglycerides, often below 100 mg/dL. This is the range at which the Friedewald equation becomes unreliable, resulting in artificially inflated LDL numbers that make you have a heart attack just by reading them.

I had a lipid panel done a while back, just for kicks. My LDL, calculated by the Friedewald equation, was 131 mg/dL. Over 130 is considered high. Pass the statins! But wait, my triglycerides were 48 mg/dL, which is quite low. I found a paper through Dr. Eades' post that contains an equation for accurately calculating LDL in people whose triglycerides are below 100 mg/dL. Here it is (mg/dL):

LDL = TC/1.19 + TG/1.9 - HDL/1.1 - 38

I ran my numbers through this equation. My new, accurate calculated LDL? 98 mg/dL. Even the U.S. National Cholesterol Education Panel wouldn't put me on statins with an LDL like that. I managed to shave 33 mg/dL off my LDL in 2 minutes. Isn't math fun?
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