## Cholesterol and Me

I actually have never had a cholesterol level that would be considered high. The threhold for a high total cholesterol level is generally considered to be anything above 200 mg/dL. Prior to taking a statin to lower my cholesterol level, my highest total cholesterol level was 180 mg/dL. However, my father died at 45 from a heart attack and that means that I have a family history of heart disease. So my doctor recommended that I work to lower my total cholesterol level. I have taken his recommendation seriously. Prior to starting my diet, my cholesterol level while on the statin was 120 mg/dL. After my diet, it has been measured 3 times between 70 mg/dL and 80 mg/dL. In fact, my life insurance company complained that my cholesterol is now too low. I cannot win.

In my youth, I used to actually make money from cholesterol. When I was in college, I worked as a technician at a college chemistry laboratory. One of my many jobs was to grind up gallstones from a local hospital for use in organic chemistry labs as a source of cholesterol. I was amazed at how large some of the gallstones could be. They must have hurt pretty bad!

Typical Gallstones (Source: Wikipedia)

I first got interested in how my cholesterol level was calculated when I noticed that my total cholesterol level was not equal to my HDL plus LDL. A little research soon showed that triglycerides were involved in the equation. I will have more to say about this later in this post.

Most people have had a fasting cholesterol test. A routine fasting cholesterol test measures three things:

• Total Cholestrol (TC)
• Triglycerides (TG)
• High-Density Lipoprotein (HDL) cholesterol

People often refer to HLD as “good cholesterol” and LDL and “bad cholestrol.” Your Low Density Lipoprotein (LDL) cholesterol normally is not measured directly. It is calculated using the Friedewald formula.

$LDL = TC - HDL - \frac{{TG}}{5}$

You can google “Friedewald” about this formula and you will find a number of web sites that criticize the accuracy of this formula (e.g. Wikipedia entry on Friedewald Equaton or this blog post). The criticism center on errors that are present for folks with high triglyceride levels (greater than 400 mg/dL). As often occurs, there are competing regression equations that are claiming superior results (e.g. “Iranian” formula).

There are also some folks who claim the Freidewald formula is inaccurate for people with low total cholesterol levels. Take a look here for a start. Many of the web references state that the problem with both the Freidewald and Iranian equations are that they were developed from data gathered from people with high cholesterol levels. I will leave it to the specialists to argue these points. I will only address what my doctor does. He is a good guy and I trust him.

## Cholesterol Metrics

My doctor sends me a report with a number of cholesterol metrics on it.

• Total Cholesterol (goal is less than 200 mg/dL)
• HDL Cholesterol (goal is greater than 40 mg/dL)
• Calculated LDL Cholesterol (goal less than 100 mg/dL)
• Cholesterol HDL Ratio (goal of 4 or less)

Let’s walk through one of my pre-diet test results to illustrate what they report. I am using my pre-diet results because they are closer to what most people see.

 Parameter Value Total Cholesterol 118 mg/dL Triglycerides 88 mg/dL HDL 27 mg/dL

Given this data, you can duplicate my doctor’s LDL calculation using the Freidewald formula.

$LDL = 118\frac{{{\text{mg}}}}{{{\text{dL}}}} - 27\frac{{{\text{mg}}}}{{{\text{dL}}}} - \frac{{88\frac{{{\text{mg}}}}{{{\text{dL}}}}}}{5} = 73\;\frac{{{\text{mg}}}}{{{\text{dL}}}}$

The calculation of my cholesterol ratio can be reconstructed as shown below.

$\frac{{{\text{TC}}}}{{{\text{HDL}}}} = \frac{{118\frac{{{\text{mg}}}}{{{\text{dL}}}}}}{{27\frac{{{\text{mg}}}}{{{\text{dL}}}}}} = 4.4$

Since this old test, I have increased my HDL into the mid-30s and reduced my total cholesterol into the mid-70s. I am afraid that I will always struggle with getting my HDL above 40. I have not given up, but I have not been able to increase this number into the 40s yet.

## My Personal Experience with Diet and Cholesterol

I know of a number of people who are trying to control their cholesterol through diet alone. A quick summary of my experience would be:

• Atkin’s Diet: I tried this diet for awhile, but I could not stay on it. However, while on it I had great HDL levels. I discussed this with my doctor and he commented that he had seen similar results with other patients who were on the Atkin’s diet. However, this diet simply was not workable for me.
• Niacin supplements: I and a co-worker have both tried this. He had a problem with “flushing.” In both of our cases, niacin had minimal impact on our HDL levels.
• Exercise: I have had the most long term success with exercise. It took some time, but daily aerobic exercise is now part of my life. I actually do not feel right when I miss an exercise session.