Your blood cholesterol levels can be reported using two different types of measurement. In the United States, your values will be reported in milligrams per deciliter or mg/dL. In Canada and Europe, the measurement for cholesterol is expressed in SI units or International System of Measurement and are expressed as millimoles or mmol per liter or L.
Consideraitons
In addition to two different ways of expressing total blood cholesterol levels, there are also different types of blood tests that measure different constituents of blood lipids or fats. Total cholesterol is a combination of High Density Lipoproteins or HDL and Low Density Lipoproteins or LDL . It is easy to confuse the two; a good mnemonic is H equals healthy cholesterol and L represents lethal cholesterol.
US Measurement
Normal or target cholesterol expressed in the US as mg/dl is less than 200 LDL and 100-129 mg/dl of HDL. According to the experts at Mayo Clinic, the greater the difference, the more protection you get from your good or HDl cholesterol. If your LDL and HDL levels are more than 60 mg/dl apart, your HDL is acting as a protective factor against heart disease.
Canadian and European Measurement
Mayo Clinic suggests that for average risk cholesterol target levels expressed in SI or International System values should be less than 5.2 mmol/L of LDL and 1 to 1.5 mmol/L of HDL. Like the measurement system used in the United States, the higher your HDL level, the better. For LDL, ranges of 2.6-3.3 mmol/L are considered healthier. The values change based on your risk of heart disease. If you are at very high risk, your LDL should be below 1.8 mmol/L in Canadian and European values and below 70 mg/dl for measurements taken in the United States.
Cholesterol Ratio
Your heart disease risk is based on the relationship of your HDL and LDL levels rather than the specific numbers themselves. The number that represents the difference in your levels is known as the cholesterol ratio. The higher your HDL or healthy cholesterol level the better. The target ratio is 5:1 with the best ratio being 3:1. Interestingly, regardless of the measurement system you use, the ratio remains the same. You can determine your ratio by dividing your total cholesterol number by your HDL value. If you have questions, be sure to talk with your health care provider.
References
- Lab Tests Online: Cholesterol
- "Journal of Cardiovascular Risk"; Screening for Cardiovascular Risk: Cost-Benefit Considerations in a Comparison of Total Cholesterol Measurements and Two Compound Blood Lipid Indicies, JE Berg. 1995
- "Journal of Biopharmacetical Statistics"; Evaluationg the Agreement of Two Quantitative Assays With Repeated Measurements; Bob Zhong, 2003
- Mayo Clinic: High Cholesterol
- Mayo Clinic: High CholesterolL What Numbers Should You Aim For?
