What do I actually know about cholesterol?
by Azure Grant
I wondered this when I received an invitation to a QS project revolving around much-more-frequent-than-normal blood lipid testing. I had heard my cholesterol wasn’t supposed to be too high, but I had no idea what my cholesterol currently was, or what too high meant. And what did cholesterol do anyways, aside from threaten to one day help coat my arteries? I joined Blood Testers, dove into the lipid and cardiovascular disease literature, and realized the answers to my questions were pretty murky.
It turns out that the basic functions of lipid components — including total cholesterol, triglycerides, HDL and LDL, not to mention their roles in CVD — are an active area of research. Moreover, the dynamic actions of these compounds on short timescales (say hours, days, and months) are even less well characterized. Feeling confused yet? Well, that’s why we made an animation. To explain the basics of what these mysterious compounds do, check out my collection of silly pictures:
And if you’re wondering why we’re collecting what is to our knowledge the highest temporal resolution human lipid data set ever, stay tuned. (get it?). We have another animation to explain that coming up.
TLDW? ; Here’s what you learn in the video:
- For the first time, people can precisely test their lipids at home.
- Triglycerides (Trigs) are a form of fat taken up from food, transported by VLDL, and stored in fat cells.
- Cholesterol (TC) does a lot of things. It’s part of your cellular membranes, it’s a precursor to sex, stress, and Vitamin D hormones, and it’s affected by basically every thing you do: time, food, activity, sleep, stress.
- Lipoproteins, including LDL and HDL, surround cholesterol and carry it through the blood.
- Lipoproteins vary almost continuously in size (remember size~1/density)- so the difference between HDL, IDL, LDL, VLDL is in part statistical. Lipoproteins are also distinguished by the Apolipoprotein markers they carry: ApoB for LDL and VLDL, ApoA for HDL
- Types of LDL are still being studied, so a lot of tests will estimate LDL level with the Friedewald Equation: LDL-c= TC-HDL-.25*Trigs . Not super accurate.
- Small dense LDL is currently a *bad guy*
- Canonically: LDL carries cholesterol & trigs out to the body for use, and HDL takes them to the liver for breakdown. So if LDL is the cholesterol hose, HDL is the drain. But…in humans…HDL can become a clogged drain. Or a weird hose. So welcome to the uncertainty.
- LDL can become dysfunctional in the presence of inflammation, and contribute to arterial plaque formation.
- None of these components are static: they do different things at different times of day, month, and year. These dynamics by definition carry more information about health than any one individual measurement.
Remind Me, What Questions Does Blood Testers Seek Answers To?
Through in-person meetings, webinars, and one-on-one online chats, participants are engaging three questions.
- What can we learn about ethical review, experimental design, execution, analysis and presentation by working in a group?
- Given that lipids change over hours and days, but are normally measured but once per year, can we learn something new about our health by mapping these high-frequency changes?
- Each of us are conducting N-of-1 Experiments. Questions include: How do my lipids vary across my ovulatory cycle? Can I develop a high-lipemic-index food list, along with a personal glycemic index? How can Tai-Chi and Video Games improve my lipid profile?
Have a thought on this? Is this your field of expertise, or something you take an interest in on the side? Please write a comment in the response box at the bottom of the page — this is the place we’d love to hear from you.
