Will the real LDL please stand up?

The results of the latest Heart Scan Blog poll are in.

The question: How has your LDL been measured? The 187 responses broke down as:


I have only had a conventional calculated value
108 (57%)

NMR LDL particle number
35 (18%)

Apoprotein B
21 (11%)

Direct LDL cholesterol
21 (11%)

Non-HDL cholesterol
8 (4%)

I don't know what you're talking about
23 (12%)


Remember the TV game show, To Tell the Truth? Celebrities would have to guess which of three guests represented the real person, such as the notorious con man, Frank Abagnale, Jr., or Mad Magazine publisher, William M. Gaines (who stumped celebrity Kitty Carlisle, heard to exclaim, "I never figured it was him. I mean look at the way he's dressed. I was looking for someone who ran a very successful magazine, so I thought it couldn't be him!")

The celebrities playing the game were permitted to ask the three guests a series of questions, hoping to discern who was the real person vs. the two impostors. At the end, each celebrity had to guess who was truly the person of interest. "Will the real Frank Abagnale, Jr. please stand up!"

If we were to act as the celebrities in our LDL game, we quickly discover some telling facts:

--Conventional LDL cholesterol (the only value 57% of our poll respondents have had) is calculated, not measured. LDL is calculated using the 40-year old Friedewald calculation.

--Directly measured LDL cholesterol (the value 11% of respondents had) is just that: directly measured. It eliminates some of the uncertainties of calculated LDL.

--Apoprotein B-Every LDL and VLDL particle produced by the liver contains one apoprotein B molecule. ApoB therefore provides a crude particle count measure of LDL and VLDL particles. Of course, it includes VLDL and is not completely the same as just an LDL measure. Some lipid authorities Like Dr. Peter Kwiterovich have advocated that apoB replace calculated LDL, and that calculated LDL essentially be discarded.

--Non-HDL cholesterol--I mention this more for completeness. Hardly anybody uses this crude value in practice--Indeed, only 4% of our poll respondents had this measure/calculation. Non-HDL is simply total cholesterol minus HDL cholesterol = Non-HDL cholesterol. It is thus a combination of cholesterol in LDL and VLDL (triglycerides), similar to apoprotein B. While, like apoB, it is a bit different in that it includes VLDL, it has proven a superior measure of risk.

--LDL particle number--In my view, this is the gold standard for LDL and risk measurement, obtained by only 18% of our poll respondents. LDL particle number is proving superior for discriminating who is truly at risk for a cardiovascular event, particularly when metabolic syndrome or diabetes is part of the picture, i.e., when HDL and triglycerides are considerably distorted, leading to substantial corruption of calculated LDL.


While 18% is a minority, it still represents growth in recognition that conventional calculated LDL cholesterol is an unreliable, inaccurate, and outdated value. If the real LDL were to stand up, I believe that it is LDL particle number that would spring to its feet.

Comments (13) -

  • Jan Jones, M.A.in Education, B.S. in Education

    4/28/2009 3:48:00 PM |

    This post comes with great timing for me, in a way...
    I just went to my dr last week to have my cholesterol checked since I have been on Dr. Davis' recommended protocol for 3 months and wanted to get accurate results to determine my current progress. In January my dr was recommending statins for me due to a slightly elevated LDL with an HDL of 65
    /trig-80/tot-235.

    At my appt. I asked her to do the test to get specific results for my LDL naming the best tests mentioned here. She looked at me as if I was from Mars and told me she never heard of such tests and those type of results would be of no benefit to any course of treatment and my insurance probably wouldn't pay for them because they may be experimental...got the picture.  Lots of resistance.  She then asked me where I got all of these ideas and so I told her about this "blog" well you can imagine her little grin as the dreaded internet doctoring reared its ugly head.  So, she said let's go to my office and look up this "blog" so I can see exactly what this LDL test is.  Low and behold as she put in the heartscan blog address, it came back ACCESS DENIED.  She tried several times and could not get in because the Scripps Medical Group system has it blocked.  

    So, I ended up getting a regular lipid panel and she added a Lp(a) test and kept saying something about fluffy particles. I don't have results yet but I am definitely feeling a lack of confidence in this physician who seems very together in a busy practice, yet isn't up on things to manage preventative care in a knowledgeable way.  How do we find primary care drs who know what they are doing?  For those of us in our 50's it is crucial to get these things under control to lead healthy lives and avoid many common problems that plague people as they get older.

    My husband and I don't want to wait until we need a cardiologist to get the type of information we are getting here.  

    Jan

  • Kiwi

    4/28/2009 11:58:00 PM |

    Jan,
    Even my cardiologist is ignorant about LDL particle sizes so what hope for the poor local Dr.

  • mark

    4/29/2009 2:04:00 AM |

    I thought the whole basis for cholesterol being bad was centered on lipoproteins and not on cholesterol itself.  It is the Friedewald equation which has been used in arguing for cholesterol being bad.  So even though cholesterol tests are inaccurate, it doesn't matter, becasue the whole basis for the lipid hypothesis was based around lipoproteins and that Friedewald equation.

    Would the same studies implicate cholesterol (in the lipoprotein) if more accurate tests were used?  

    It could explain why in so many studies, HDL and LDL have conflicting correlations.  In one set of individuals, high LDL indicates high LDL cholesterol.  That is to say, for a certain lifestyle and environmental and genetic factors, the individuals with high LDL will also have high LDL cholesterol.  

    Then in other populations, their lifestyle (and other factors) makes it so that high LDL lipoproteins does not coincide with high LDL cholesterol.  

    Or some individuals with low LDL can have high LDL cholesterol.  

    Mark.

  • Drs. Cynthia and David

    4/29/2009 8:37:00 AM |

    Sadly, I suspect much of the reason for sticking with the inaccurate and misleading LDL #s is that much of the research is paid for by drug companies pushing LDL lowering drugs, so of course it is not in their interest to have the truth come out that LDL per se is not really important.  Does taking a statin reduce the number of LDL particles? or just the amount of cholesterol in the particles?

    It's also horrifying (as Jan comments above) that this site is blocked by the medical establishment.  No wonder the doctors don't know anything- they can't even look up information easily!

    Thanks for all your educational posts.  There is still a lot of resistance out there,  but I think you are making progress.

    Cynthia

  • vin

    4/29/2009 11:07:00 AM |

    18% is very unlikely to be true for the total population. I think the actual number is much lower.
    The question should really be put to health care people : which test do they use for their patients?

  • steve k

    4/30/2009 12:36:00 AM |

    can you explain the difference between 25(0h)2 vs. 1.25?  What does it mean if the 1.25 is high and not the 25(oh)2 which you say should be measured.  I have been taking D3 and agree with all the benefits cited.  Thank you

  • Trinkwasser

    4/30/2009 8:19:00 AM |

    In many parts of the UK you can only get TChol. Lipid panels are "too expensive". They need to save money on the tests to afford the statins. My GP is clueful enough to turn a blind eye when I biro in the Full Lipid Panel, and also to interpret the results (LDL is nominally over limit but is trumped by my excellent trigs and HDL) but her cluefulness is very constrained by the accountants. They pay bribes to get a certain % of patients on statins irrespective.

  • homertobias

    4/30/2009 4:51:00 PM |

    Jan
    Was it Scripps Clinic or Scripps La Jolla?  Was it simply that her in house computer was blocked from surfing the internet?  This is very common.  Lab corp or Quest (better) will run your NMR.  Just have your doctor order it and find a draw station.  Blood needs to be spun and needs a YELLOW and BLACK tube.

  • Jan Jones, M.A.in Education, B.S. in Education

    5/1/2009 2:03:00 PM |

    homertobias,

    The dr is with Scripps Clinic and she had access to the internet in her private office without any apparent problems.  When she entered the address of the blog it was blocked and when a google search of dr. davis found the blog that too would not open.  

    I had written down all of the tests that dr davis recommends here and she had no idea what that was about. I asked for NMR  and she didn't know what to order, which was why she wanted to go to the blog to see it for herself.

    I got my lipid panel results yesterday but the Lp(a) test she ordered did not come back.  They're checking on that one.  

    Thanks for the info.

    Jan

  • RyanVM

    5/1/2009 11:20:00 PM |

    I'm betting they just have a generic block on blog sites (blogger, wordpress, etc).

  • Mark K. Sprengel

    6/18/2009 12:19:04 AM |

    I'm pretty sure my insurance uses the calculated LDL value. It's rather irritating as our annual blood test scores are used along with a series of questions about diet/exercise etc. to determine how much of a credit we get on our paychecks. They also use the BMI which I've read is very innacurate for athletic/lean bodies. Our human resources rep had no answer when I pointed out it would probably put me at overweight if I was 210 lbs at 6' tall but 10% bodyfat even though I would be healthier.

  • Trinkwasser

    7/14/2009 1:41:43 PM |

    This is useful. I can't remember who posted it but all credit to them. The Iranian Formula corrects for the low trigs I hope we all have where the Friedewald Equation falls apart

    http://homepages.slingshot.co.nz/~geoff36/LDL_mg.htm

  • Robin

    11/2/2012 3:54:08 AM |

    If they were interested enough, they'd look it up on their own computers when they got home. If they had only a business laptop, which would lock them out of helpful sites, then they'd find a way of doing their own research - just like the rest of us have to when not relying on the medical establishment.

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