In the previous article, I tried to bring light to some of the scary “truths” about cholesterol and what in fact cholesterol is, what it does and how it affects our health. This post will be a little shorter and my goal is to help you understand and interpret cholesterol blood markers. If any of you has ever requested blood work from the doctor to get a complete cholesterol and blood lipid panel, the results can be overwhelming and confusing. Most of us, including the doctors, just scan the results and look for the word “HIGH”. This is the scary notification that something is not optimal with our health. In truth, having a a score of LOW on certain markers is just as bad, if not worse as having something higher than what is considered normal. Here is a run-down of some basic blood markers of cholesterol and lipids and what the doctor and your cardiologist would like to see:
FASTING LIPID PANEL REFERENCE RANGE
TOTAL CHOLESTEROL 125-200mg/dl
HDL CHOLESTEROL >OR= 40mg/dl
LDL CHOLESTEROL <130mg/dl
CHOLESTEROL/HDL RATIO <5.0
NON-HDL CHOLESTEROL about 30mg/dl higher than LDL cholesterol target
BLOOD GLUCOSE <or= 110mg/dl
As discussed in the previous article, having ultra-low LDL is not healthy, nor should it be your goal. If you have really low LDL levels then your cells aren't getting the cholesterol, lipoproteins and fat soluble vitamins they need to function properly. One caveat is that, as previously mentioned, cholesterol acts as an antioxidant in the body and is elevated in times of stress. If you are having a particularly stressful period in life or have been sick for a long time, then your cholesterol may be artificially elevated to deal with your circumstances, so keep that in mind.
I also included fasting blood glucose because this is another marker that has implications in your cholesterol blood work, but we will cover that in a bit. If you just take a general look at all of the markers listed, you can see that your doctor is also interested in more than your total cholesterol, which is good, because some of these other numbers can tell us more than total cholesterol can. What is as important as total cholesterol and LDL markers, is your HDL level. This is the lipoprotein that we want higher because it is shuttling excess cholesterol and lipids away from our cells and out of our bloodstream, so they don't oxidize, collect on arterial walls and damage arterial linings. As an example, if your total cholesterol looked good, let's say 150mg/dl, and your LDL was 115mg/dl, neither of those numbers would be flagged as high. However, that only leaves 35mg/dl of HDL cholesterol working to shuttle excess cholesterol and lipids back to the liver. You can even see from the panel that they would prefer HDL to be greater than or equal to 40mg/dl. So looking at total and even LDL cholesterol doesn't give you the whole story.
Let's choose another scenario, this time where your LDL cholesterol was high and this brought your total cholesterol over the reference range. All is lost, right? No more bacon, butter, eggs, red meat, cheese or cream ever again. There is a ray of light at the end of this cholesterol encrusted tunnel because if the HDL was also high in this case, the other numbers might not be indicative of poor health. To throw out some numbers in this example, we'll say that total cholesterol is 210mg/dl, LDL is 140mg/dl and HDL is 70mg/dl. In this case, everything is high, but the HDL matches the LDL in terms of elevation meaning that we don't necessarily have all this extra fat and cholesterol floating around our bodies and clinging to our arteries. How do we know? The cholesterol/HDL ratio. This ratio usually runs between 3 and 7, meaning a ratio of 3 is great and 7 is go-to-the-doctor-right-now-and-get-checked-out. This is total cholesterol divided by HDL. In this example, our patient has a ratio of 3, which is excellent. In this case, the patient's cholesterol levels might be totally healthy.
These numbers don't ensure good health, but studies have shown that the total cholesterol/HDL ratio is a better predictor of heart disease and artherosclerosis than looking at just total cholesterol and/or LDL. In a study referenced by Chris Masterjohn (check references below), results from 61 studies on heart disease were pooled, totaling 12 million person-years, with 55,000 deaths cited throughout all the studies. In this study, total cholesterol was the worse predictor of heart disease and the total cholesterol/HDL ratio was the best predictor. Something to think about.
The final blood lipid and cholesterol marker to check is your triglyceride levels. Blood lipids show how much triglycerides(fat) are being carried in your blood by your lipoproteins, like LDL. Generally, low blood triglyceride levels are a good marker of health because it shows that we do not have excess lipids floating around in our blood. As in the case with high total cholesterol, low triglycerides means that even if we have a lot of LDL going to our cells, we don't have an excess of lipids being carried with them. However, low total cholesterol with very high blood lipids may mean that your LDL are saturated with blood lipids, meaning your liver may be turning excess glucose into blood lipids(fat). In this case check to see if your high blood triglycerides are accompanied by high fasting glucose.
BONUS BLOOD PANEL
High blood glucose and high triglycerides would be an indicator of insulin resistance and possible diabetes. In terms of diabetes, your body is not producing enough insulin to clear the excess glucose from the blood and much of that is then converted to fat. In terms of insulin resistance, your cells are not sensitive to insulin, then the pancreas has to release way more insulin than normal to clear it from the blood; this produces those highs and lows in blood sugar because blood sugar is high after eating and then drastically low after the pancreas pumps out tons of insulin. In both cases, your muscles become less and less sensitive to insulin and fat cells take over as the primary storage sites.
Now, to touch on blood glucose, elevated blood glucose is a marker of insulin and pancreas health and is used as a predictor for diabetes. High blood glucose levels can mean that your pancreas isn't producing enough insulin to clear it from the blood, excess stress causing glucose to be released from the liver or possible other illness like a stroke, heart attack or excess growth hormone. The biggest issue for most people is pancreas health, and having higher than normal blood glucose may be due to abnormally low insulin levels due to diabetic conditions(think Type-1 diabetes). Very low blood glucose can be due to too much insulin(think pre-diabetes), where your body produces more than necessary and drops your blood glucose way too low, leading to hypoglycemia. Anorexia, liver disease and low-thyroid function can also cause this, but once again, insulin is most likely the cause for most people.
Blood glucose markers are important in blood lipid and cholesterol panels because you don't want elevated blood glucose and blood lipid levels. This creates an environment for excess fat storage where the blood glucose needs to be stored either in the liver or turned into fat in our fat cells, making it easier for the lipids to be stored as fat alongside it. Take home point here is if your total cholesterol and LDL is high, but HDL is high, blood glucose is low and triglycerides are low, than your health is probably pretty good.
This did get technical but remember that looking at one or two blood markers doesn't tell us the whole story. Take all of this information into account and also remember that lab values differ from lab to lab, so your doctor may have slightly different reference ranges than the ones shown here. Either way, when your blood work is done, check ALL markers, look at your total/HDL ratio, triglycerides and glucose. Things may be better than you think.