Why not albumin
Albumin lives in the blood for about three weeks, so it reacts slowly to changes in nutrition: during acute starvation, its level remains normal for a long time. Prealbumin is renewed within 2 days, and its decrease reflects protein deficiency in almost real time. This makes the indicator the main tool for assessing nutritional status in severely ill patients, with parenteral nutrition, after major operations and in chronic diseases with depletion. It also serves as a criterion for the effectiveness of nutritional support: the increase in prealbumin after a few days confirms that the nutrition has been chosen correctly.
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.