- Lipids, or Fats
- Blood Tests
- Other Main Heart Risk Factors
Lipids, fats, cholesterol, LDL, HDL – what do they mean
As a test, refers to the group of circulating fats inclusive of so called good and bad fats. It could be argued that any fats produced by the body must serve some purpose. In a perfect world this may be true, however because fats are bio chemically quite unstable, that is they are prone to going ‘rancid’, and in the presence of ‘oxidising’ factors such as toxins, pollutants, drugs, waste products and other factors, they can be oxidised and become harmful. Leave butter out in the sun for a day and taste it!
Fats are essential to life. Much of our brain and nervous system is fat. Every cell has fat(lipid)-protein layers; many hormones are synthesised in our glands and liver from cholesterol; our immune system is highly dependent on fats. So it would be very worthwhile respecting, protecting and not depleting essential fats. Here we will explore the fats that are typically measured as Blood Lipids, rather than discuss the issues of dietary fats like saturated, unsaturated, polyunsaturated, EFA’s and so on….
So what is the problem with ‘cholesterol’?
It gets oxidised by environmental pollutants, dietary neglect as well as other biochemical factors! Then it does harm to the arteries and other tissues. Of course the body attempts to reduce this oxidising process with natural antioxidants as one example. That is why off the shelf cooking oils have antioxidants added to stop the oil going rancid too quickly.
Why are doctors so concerned to reduce cholesterol levels? Firstly it is important to recognise which subgroup of the lipid group is the concern. There is a link between high levels of some lipids with heart disease severity. Certain drugs, such as the ‘Statin’ family can reduce these levels very dramatically. Controversy arises as to how low should these lipid levels be forced, not that there is dispute about the benefits of statin drugs and cardiac risk, but there may be other non-heart related disadvantages and side-effects.
Categorising types of fats – the good, bad and the ugly
Cholesterol as a fat is transported around in the blood attached to a protein carrier. Its this protein that determines what happens to the fat. Standard Lipid Testing may not accurately ‘test’ the risks properly. Some labs can do more expanded assessments. Some people having heart attacks may have normal standard Lipid Tests but not until delving more deeply do the faults appear.
For more information on the Fredericksen classification of LIPID abnormalities see Wikipedia Lipidaemia
Depending on location, the upper table blood work cost is generally covered under local Health Board free system.
Advanced Lipid profiling is not available in view of perceived ‘lack of proof’ of relevance. However, with advances in technology and the explosion of knowledge – it is unlikely that ‘free’ laboratory offered tests will reflect the most contemporary situation. The downside is that when testing in the advanced areas of technology, the risk is that information may change as new research comes in. Well if we never utilise new knowledge we would never advance – but more importantly, many of us dont have time to wait 10 or more years for any absolute certainty, (which by the way, in medicine is a rare event!).
For locations of laboratories that will do advanced Lipid Profiling, please locate the link on the right side-bar. I can arrange the test – however, the blood must be fresh so time it when you are next in Australia.
Ideal Range nmol/L
|Cholesterol||Is the total of all the subgroups, so may comprise good and bad fats. May not mean much by itself therefore.||4.34 – 5.91|
|Triglycerides||Most of the body’s fat is stored in this form and only a small amount should be in the blood. By themselves triglycerides don’t cause heart problems but if high, then they do influence the bad fats like LDL and VLDL.||0.62 – 2.26|
|LDL (Low Density Lipoproteins) ‘Bad fat’||Is actually a mixture of lipoprotein particle types. Some are worse than others. It seems the particle number rather than just particle type is more important. Its measured as apoprotein B.||2.4 – 3.83|
|HDL (High Density Lipoproteins) ‘Good fat’||Also a mixture. The larger HDL particles are good at extracting cholesterol out of atheroma plaques. It has other benefits too. Small particles don’t have this usefulness. So it would be beneficial to know the subtypes is possible. Some labs can.||1.05 – 2.25|
|Cholesterol / HDL Ratio||The lower the better, meaning more HDL than bad fats. A guide.||less then 4.5|
|LDL / HDL||The lower the better, compares bad fat with good fat. A guide.||less then 2.8|
Advanced Testing (not available in New Zealand) Offshore Test
|LDL Particle Number Apo B||Is very strongly linked to heart attack risk. Actual counting is very specialised by nuclear magnetic resonance spectroscopy, but more easily but indirectly by the apoprotein B test.
Apo B is the main protein in LDL. So you could have a low LDL (low risk) but a high count which is high risk.
Management: Oat Bran reduces particle number and size as does flaxseed, psyllium. Raw nuts, almonds,walnuts, pecans.
Soy protein, Glucomannan fibre before emails, Stanol/sterol butter substitiutes.
Chitosan 1-2 gms/day. Legumes – black, red, black, lima beans.
|LDL Small Size LDL||LDL particles can be small, medium and large, like jeans! Its the small ones that are deadly. They easily penetrate the blood vessel walls and they hang around longer, clinging to that delicate artery lining called endothelium. It can make you more at risk of being ‘insulin resistant’ or even diabetic if overweight. It trebles heart attack risk and if the CRP is high 6x the risk.Genetic factors if strong can cause high risk even if otherwise healthy. Risk increases with unhealthy lifestyle and being overweight.
Weight loss quickly increases LDL size.
Niacin 500mg to 1500mg corrects size (must be under medical supervision.)
Diet – reduce sugar release with: ground flaxseed, mediterranean diet. Low GI foods, high fibre, psyllium, oatbran, nuts – almond, pistachio, walnut, omega 3 fish oil espec if triglycerides elevated.
Strict low fat diet may actually worsen this.
|HDL Size Large HDL (HDL2b)||Half of heart disease people have low HDL. Many have a low protective subclass of HDL which are the large particles called HDL2b or simply large HDL. Crucial for getting cholesterol out of plaque. Usually the higher your HDL the more likely you will have enough large HDL.
Same as for treating small LDL particle size.Strict low fat diets are NOT advised as it may generate more small HDL particles when total HDL is very low.
Med Diet – nuts, olive oil, olives, Low GI diet, increase protein source from oily fish. Supplement with fish oil option.
|Intermediate Density Lipoproteins IDL||Very potent risk for heart disease. High IDL’s slow down the clearing of fat from the blood after eating. When fats hang around longer, they can get oxidized more and cause damage. About 10% have raised IDL.
Cholesterol drugs work well.
Niacin (B3), Fish oils, Weight management.
|Very Low Density LipoproteinsVLDL||Are packed with triglycerides, so if trigs are high then these VLDL’s may also. VLDL’s get into the LDL and HDL causing small particles of LDL and deficient large HDL!
High dose fish oil 4-10 gms., Increase fibre.
|Lp(a) Lipoprotein (a)||Lipoprotein ‘little a’ is a very potent risk factor. 20% may have it, leading to heart attacks early in life; 40’s to 50’s. It seems to accelerate plaque growth and rupture as well as increase other risk factors’ dangers.
Niacin is effective under supervision 1000-4000mg daily.
Estrogens can help in women (consider other risks with E replacement).
Testosterone for men reduces Lp(a).
L-Carnitine (1gm twice daily).
Vit C – gms per day.
Test or Risk Factor
|hsCRP (C-Reactive Protein)||Inflammation is the underlying cause and key to the generation of future plaque. Inflammation is also the basis for many if not most of the body’s diseases even cancer. CRP is a non-specific test which signals inflammation going on somewhere. In the absence of other known inflammation, a low level of CRP could indicate a 3 fold increase risk of heart attack. Especially the hsCRP (high sensitivity CRP) is elevated. CRP not only is a ‘marker’, it also directly injures the endothelial lining.
Lifestyle, exercise, Mediet, oils, Supplement oils, Aspirin, Vit C and flavanoids, Vit E.
|Homocysteine||This has been covered elsewhere. Must reduce at least under 11 but better under 8. Homocysteine also damaging to brain cells and is major factor for brain decline and dementia (Alzheimer’s Disease). B12 and Folinic acid helps if mutations present.|
|Fibrinogen||Fibrinogen is a necessary part of the blood clotting system to prevent bleeding when a blood vessel is injured when it turns into fibrin threads which help make a clot. Too much fibrinogen can increase the generation of clots (thrombosis) leading to a heart attack, stroke or other damage from blocked arteries. Poor diet, lifestyle raises fibrinogen. Estrogen may increase it in some at risk women. Certain types of HRT.
Fish oil, Mediet, plant foods ++, exercise, Vit B3 (Niacin), Fibrate meds class.
|Blood Pressure||Major risk|
|Overweight, obesity||Modest risk, worse if have Metabolic Syndrome.
Low glycaemic Mediterranean style.
|Lack of exercise||Modest risk.
Must do daily cardio fitness.
|Family history||Especially when associated with high risk lipid profile in the family.|
|Insulin Resistance||Also called Metabolic Syndrome, Syndrome X. Read more.
Must reduce abdominal circumference to under 100cm males, 80 females.