# What is 'Real LDL'?

Discussion in 'Ask A Question' started by Colin of Kent, Dec 29, 2018.

1. ### Colin of Kent Type 1 · Well-Known Member

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In his 'Diabetes Solution' book, Dr Bernstein makes reference to measuring something he calls 'real LDL', but he doesn't seem to explain what he means by that (unless I've missed it - I haven't read the appendices exhaustively). Can anyone here enlighten me?

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2. ### bulkbiker Type 2 · Oracle

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So faras I know LDL is usually calculated using a formula .. the name of which escapes me.. maybe "Real LDL" is LDL that has actually been measured rather than calculated?
@Bluetit1802 is usually more on the ball than me about that!

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3. ### bulkbiker Type 2 · Oracle

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"
How Is LDL Cholesterol Calculated?
Cholesterol levels are measured in milligrams (mg) of cholesterol per deciliter (dL) of blood in the US and some other countries. Canada and most European countries measure cholesterol in millimoles (mmol) per liter (L) of blood.

Blood tests typically report LDL-C. These numbers are usually based on calculation, using the Friedewald equation that includes total cholesterol, HDL-C, and triglycerides. This equation relies on the assumption that the ratio of triglyceride to cholesterol is constant, which is not always the case.

If mg/dl is your unit, like in the United States the formula looks like this:

LDL cholesterol = [Total cholesterol] – [HDL cholesterol] – [TG]:5

If mmol/l is your unit like in Australia, Canada, and Europe the formula looks like this:

LDL cholesterol = [Total cholesterol] – [HDL cholesterol] – [TG]:2.2

Thus, LDL-C calculations may have limitations when blood triglyceride levels are either high or low. Direct LDL -C measurements are also available, but are less often done due to higher costs.

Some studies show that the number of LDL particles (LDL-P) may be a better predictor of risk than LDL-C. LDL particle size may also be important when assessing risk."

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4. ### Bluetit1802 Type 2 (in remission!) · Legend

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Sorry, no idea what real LDL is, but your guess seems reasonable to me.

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5. ### Bluetit1802 Type 2 (in remission!) · Legend

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How low is low? Do we know? I wonder if mine are low according to that, at 0.6. According to the standard range on my lab reports, the range starts at zero. So presumably if we have no trigs we are still normal.

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6. ### librarising LADA · Well-Known Member

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There are two formulas for calculating LDL, Friedewald and Iranian :

The limitations of the Friedewald equation are explained here (overestimating LDL on a low carb diet) :
https://www.docsopinion.com/2017/01/02/ldl-cholesterol-overestimated-low-carb-high-fat-lchf-diet/
Geoff

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7. ### bulkbiker Type 2 · Oracle

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It was from here but doesn't say what is "low" or "high"

https://www.docsopinion.com/health-and-nutrition/lipids/ldl-c/

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8. ### librarising LADA · Well-Known Member

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"Statistical analysis showed that when triglyceride is <100 mg/dL, calculated low- density lipoprotein cholesterol is significantly overestimated"
https://www.ncbi.nlm.nih.gov/pubmed/18426324
100 mg/dL equates to 2.6 mmol/L
**Correction** THIS IS WRONG. It equates to 1.13 mmol/L
Geoff
edited for correction (thread explains why)

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Last edited: Dec 29, 2018
9. ### Bluetit1802 Type 2 (in remission!) · Legend

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Interesting. I don't consider 2.6mmol/l low. I consider it high! 1.9mmol/l is the top end of the normal standard range for fasting, and up to 2.3mmol/ not fasting, which means most of us have what they say is low trigs, whether low carb or not.

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10. ### bulkbiker Type 2 · Oracle

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Isn't 100mg/dl - 5.5 mmol/l? does the divide by 18 rule not apply when its triglycerides?

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11. ### bulkbiker Type 2 · Oracle

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or maybe not...

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12. ### Bluetit1802 Type 2 (in remission!) · Legend

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No, it doesn't. It is a different calculation. I used to know it, but have forgotten.

Just seen your above post. Well done, that makes more sense than the one @librarising came up with. So basically, under 1.1mmol/l is low.

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13. ### librarising LADA · Well-Known Member

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We're both wrong. I'd searched a trigs converter, and failed to notice it was a cholesterol converter !
It's blood readings that convert at a ratio of 18.
Since mg/dL is measuring something different in nature to mmol/L, US mg/dL measurements of cholesterol and trigs convert at different rates to UK mmol/L.
Cholesterol : 1 mmol/L = 38.8 mg/dL
Triglycerides : 1 mmol/L = 88.5 mg/dL

So 100 mg/dL is not 2.6 mmol/L but 1.13 mmol/L
This is why US trigs/HDL ratios are roughly twice UK ratios.

Hope that makes sense !
Geoff

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14. ### bulkbiker Type 2 · Oracle

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****** complicated all these differing units.. Interesting though that Blood Glucose converts by dividing by 18 but trigs don't even though the units are the same.. mg/dl to mmol/l ...

Ed by mod for language.

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Last edited by a moderator: Dec 31, 2018
15. ### bulkbiker Type 2 · Oracle

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Ah so that explains my post above.. thanks Geoff

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16. ### Bluetit1802 Type 2 (in remission!) · Legend

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Maybe the USA includes fibre in the trigs count. LOL.

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17. ### librarising LADA · Well-Known Member

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18. ### Mr_Pot Type 2 · Well-Known Member

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The molecular weight of triglyceride is different to that of glucose so a mole of each substance will have a different weight and the conversion to mg/dl is not the same.

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19. ### librarising LADA · Well-Known Member

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