Blood

Blood Markers We Assess & What They Tell Us

Basic Labs

CBC (Complete Blood Count)

A full blood count measures: 

• Red blood cells, which carry oxygen through the body

• Hemoglobin, the protein within red blood cells that carry oxygen

• White blood cells, which fight infection

• Platelets, which help the blood to clot

Creatinine

Creatinine is a marker of kidney function. Creatinine is a waste product that comes from the digestion of protein in your food and the normal breakdown of muscle tissue. It is removed from the blood through your kidneys. If you have high levels of Creatinine, it can be a signal that your kidneys are not working properly. 

Ferritin

Ferritin is a blood protein that contains iron. Ferritin is mesasured to find out how much iron is stored by your body. If ferritin is low, this means that the body’s iron stores are low. If ferritin is high, this can be caused by several factors including infection, inflammation, liver disease, kidney disease and metabolic syndrome to name a few. Elevated ferritin can also be caused by hemochromatosis which is a condition in which your body b uilds up a significant amount of iron in its tissues.

Ferritin is important to know because if it is low it can lead to symptoms of fatigue and poor exercise tolerance. For menstruating women, low ferritin is quite common and some experts believe this is an under-diagnosed condition in women. The treatment is supplementing with iron.  

Metabolic Panel

HbA1C (Hemoglobin A1C)

Hemoglobin A1C is a test that measures the percentage of a person’s hemoglobin (the oxygen-carrying protein in red blood cells) that is coated in glucose; this indicates their average blood glucose levels from the past three months. 

One limitation of this test is that the percentage can vary depending on how long a person’s red blood cells live for. If someone has a robust red blood cell that lives for the full 120 days (its typical lifespan), then there is a good chance that the hemoglobin (the oxygen-carrying protein inside it) will be coated in glucose even if a person has normal glucose levels. This can cause a falsely elevated HbA1C. Alternatively, if a person’s red blood cells have a shorter life span, their hemoglobin may not have had the chance to be coated in glucose, even if this person’s glucose level is elevated. This can cause a falsely normal HbA1C. 

So it’s important to look at this in combination with other metabolic markers.

Fasting Insulin

This is a measurement of insulin in the fasting state, which means no food intake for the 8 hours prior to testing. High fasting insulin can be one of the earliest indicators of insulin resistance, and poor metabolic health, even before we see chronically elevated levels of blood glucose 

Fasting Glucose

This is a measurement of glucose in the fasting state. 

A fasting glucose can help identify issues with metabolizing carbohydrates. Fasting glucose greater than or equal to 7.0 mmol/L is a diagnosis of diabetes, as per our Clinical Practice Guidelines from Diabetes Canada. 

Elevated fasting glucose is a late finding of metabolic dysfunction. Well before a person has elevated fasting glucose, they will have evidence of insulin resistance, including elevated levels of fasting insulin. 

Vitamin D

Vitamin D is naturally produced in the body when sunlight hits your skin and triggers the conversion of 7-dehydrocholesterol to vitamin D3. Vitamin D3 is what we test in your blood. Vitamin D3 enters the circulation and is converted to active Vitamin D after a series of reactions involving the liver and kidneys. 

Vitamin D has several critical functions, including the following:

• It facilitates the absorption of calcium in the gastrointestinal tract, important for bone strength and muscle contraction. 

• It is thought to promote vasodilation (widening of blood vessels), which improves blood flow and reduces blood pressure.

• It also helps with the function of insulin to maintain stable blood glucose. 

ALT (Alanine Transferase)

Alanine Transferase (ALT) is an enzyme which is primarily found in the liver but can also be found in kidneys, heart, muscles, and the pancreas. If this marker is elevated, it can be a result of liver damage from several different causes, including fatty liver disease, recent infection, alcohol intake, hepatitis, and cirrhosis (a serious liver disease)

One of the most common reasons for elevated ALT is fatty liver disease, which creates serious metabolic health issues. 

AST (Asparate Aminotransferase)

Asparate Aminotransferase (AST) is an enzyme that is mostly found in the liver but also found in red blood cells, heart, muscle, pancreas and kidneys. Elevated levels of AST usually signal damage to the liver. Recent infection, alcohol intake, hepatitis, cirrhosis and fatty liver are all reasons for AST to be elevated. 

The ratio of AST to ALT sometimes can help determine the cause of liver damage. 

Some experts consider AST to be a marker of mitochondrial function, responsible for energy production within the cell.

Lipid Panel

Total Cholesterol

Total Cholesterol in your blood includes High-Density Lipoprotein (HDL) and Low-Density Lipoprotein (LDL). This test comes as a standard when ordering a lipid profile, but Total Cholesterol is not particularly helpful; it is much more important to look at the breakdown of cholesterol. 

Triglycerides

Triglycerides are a type of fat resulting from excess caloric consumption. They are mainly carried through the blood by Very Low Density Lipoproteins (vLDL) – these lipoproteins increase your risk of cardiovascular disease, because they can embed in the arterial wall and cause plaque. 

Elevated levels of Triglycerides can indicate elevated blood glucose, insulin resistance, metabolic syndrome, and diabetes, as well as other serious issues. Consuming refined grains, sugars, and processed foods can cause elevated Triglyceride levels. Certain medications, hypothyroidism, acute illness and a recent meal can cause falsely elevated Triglyceride levels.

High Density Lipoprotein (HDL)

High Density Lipoprotein (HDL) is a type of protein that carries cholesterol in the blood. HDL is able to reduce cholesterol in the blood, by pulling it away from the arteries and back to the liver for redistribution, metabolism and elimination. This is why HDL is thought to be the “good cholesterol;” however, for HDL to truly be “good”, it has to function well, and we can’t determine that by measuring HDL alone. Low HDL is associated with insulin resistance and associated with heart disease. 

Triglyceride:HDL Ratio

High Triglyceride:HDL ratio is strongly associated with cardiovascular disease, insulin resistance and metabolic syndrome. 

A Triglyceride-to-HDL ratio of more than 2.5:1 in Caucasians or more than 1.5:1 in African Americans, is thought to be a marker of metabolic syndrome. The American Heart Association (AHA) consider a Triglyceride-to-HDL ratio of <=2 optimal, and a ratio of 3.8+ an indication of cardiovascular risk

Apo-B (Apolipoprotein B-100)

Apo-B is a structural protein that we find attached to each particle of Low-Density Lipoprotein (LDL). 

An LDL particle actually contains multiple types of lipoprotein, including:

• vLDL (very low density lipoprotein) - the smallest and most dangerous type

• iLDL (intermediate low density lipoprotein)

• LDL-C (LDL cholesterol)

When we get an “LDL” blood result, we’re actually only measuring LDL-C. Apo-B gives us a measure of the number of total LDL particles in the blood, which may be a better indicator of risk of cardiovascular disease than looking at LDL-C alone.

Lipoprotein (a) or "Lp(a)"

Liporprotein(a) also known as Lp(a) is a type of LDL cholesterol that can increase your risk of cardiovascular disease. It is a distinctive lipid marker because it is genetically inherited. It is estimated that 20% of the population will have an elevated Lp(a). Elevated levels of Lp(a) increase your risk of several cardiovascular diseases including coronary artery disease, aortic stenosis, heart failure and stroke. Despite its importance, research shows that Lp(a) is rarely screened for. It is recommended that everyone have this lipid test performed, typically done once in a lifetime. 

If your Lp(a) is elevated there is currently no targeted treatment specifically designed for Lp(a). The recommendation is to reduce cardiovascular risk by aggressively managing lifestyle factors like exercise, alcohol, diet and smoking. There are medications to address other markers  that can help lower Lp(a) as well. Studies are ongoing and the hope is that a targeted treatment to more effectively reduce Lp(a) will be available in the next few years.