Why do you need a ratio?
Total cholesterol itself says little about risk: it consists of “bad” fractions deposited in the vessel wall and “good” HDL cholesterol, which, on the contrary, removes cholesterol from the vascular wall. Two people with the same total cholesterol may have fundamentally different risks. The atherogenicity index is calculated as the ratio of the difference in total cholesterol and HDL to HDL and shows the balance between these processes. A value up to 3 is considered favorable, above 4 indicates a high risk of atherosclerosis. The indicator does not require a separate blood sample - it is calculated based on the results of a lipid profile and is convenient for monitoring over time.
Why preparation is so important
The laboratory result is a number, but the correct number can only be obtained if the rules are followed. Eating changes the levels of glucose, lipids and a number of enzymes significantly; physical activity the day before increases CK and AST; smoking affects hormones; time of day is critical for cortisol and testosterone.
Therefore, a “bad analysis” often turns out to be a consequence of impaired preparation, and not an illness, and leads to unnecessary examinations and prescriptions.
General rules for donating blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
- for hormones in women, take into account the day of the cycle
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important. It is up to the physician to interpret the analysis: an isolated indicator without a clinical context is often misleading.