[Evaluating parachute-drop stress by measuring blood lipids]

An attempt to evaluate parachute-drop related stress by determining the blood lipid profile (cholesterol, LDL, HDL, apo-A, apo-B, and triglycerides) is reported. Measurements were made on starting the parachute course, just before the first jump, and just after the third jump. On these 3 occasions 38 combat troops answered psychological questionnaires and 30 of them gave blood samples. While there were significant fluctuations in level of all blood lipids and their apoproteins, they could not be correlated selectively with presumed levels of stress. The well-known difficulties in field studies in controlling crucial factors such as the exact timing of the measurements and food intake (specific diet or fasting) make questionable the use of biochemical markers in measuring stress under the conditions of our study. It is possible that the high rate of refusal to give blood samples biased the findings.