Before I get into some of the confounders in my n=1 experiment I want to quickly explain the relationship between thyroid function and cholesterol (specifically lipoproteins).
Most people understand that the thyroid controls our metabolism, which in fitness terms usually means how many calories we burn. What is sometimes lost is that metabolism includes ALL of the body’s processes. So with that being said, if your thyroid isn’t functioning up to par (hypothyroidism), you will have abnormalities in your cholesterol metabolism (more importantly lipoprotein metabolism).
In my article Cholesterol is Not the Enemy I discussed that it is the LDL particles / apo B that are the real issue and not the cholesterol concentrations per se. Well in hypothyroidism (low thyroid state), LDL particles and apo B levels are increased. There are a few reasons to date that explain this:
1. There is thought to be a slight decrease in LDL receptor activity due to the decrease in metabolism. The LDL receptor takes in the LDL particles / apo B for processing which lowers the amount of LDL particles / apo B to bounce around your arteries and cause atherosclerosis.
2. There may be NON LDL receptor changes as well related to decreases in apo B production.
Either way, when you give thyroid hormone to someone with hypothyroidism, lipid/lipoprotein abnormalities improve.
As you will see in my first confounders post, this information will be helpful as I have hypothyroidism.
