| 2. |
- Ståhle, Lars, et al.
(författare)
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Effects of Food or Sleep Deprivation During Civilian Survival Training on Clinical Chemistry Variables
- 2013
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Ingår i: Wilderness & environmental medicine (Print). - : Elsevier BV. - 1080-6032 .- 1545-1534. ; 24:2, s. 146-152
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Tidskriftsartikel (refereegranskat)abstract
- Objective.-To describe clinical chemistry and weight changes after short-term food or sleep deprivation or multiple deprivations during civilian survival training. Methods.-Data from one baseline-controlled two-period crossover study designed to compare sleep deprivation for up to 50 hours with food deprivation for up to 66 hours (n = 12) and data from regular multiple-deprivations survival training comparing participants (n =-33) with nondeprived instructors (n = 10). Results.-Food deprivation was associated with decreased body weight, blood glucose, serum triglycerides, sodium, chloride, and urine pH, and there were increases in blood and urine ketones and. serum free fatty acids. Sleep deprivation was associated with a minor decrease in hemoglobin and erythrocyte particle count and volume fraction and an increase in leukocytes. Conclusions.-The clinical chemistry and body weight changes associated with food deprivation were qualitatively similar to those observed in fasting obese patients but developed quicker in the survival training setting. Sleep deprivation had few effects on the clinical chemistry profile except for hematological variables. Physicians evaluating clinical chemistry data from patients subjected to short-term food or sleep deprivation should take the physiological state into account in their assessment.
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| 3. |
- Ståhle, Lars, et al.
(författare)
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Effects of Sleep or Food Deprivation During Civilian Survival Training on Cognition, Blood Glucose and 3-OH-butyrate
- 2011
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Ingår i: Wilderness & environmental medicine (Print). - 1080-6032 .- 1545-1534. ; 22:3, s. 202-210
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Tidskriftsartikel (refereegranskat)abstract
- Objectives.-The study was designed to compare effects of food deprivation (FD) and sleep deprivation (SD) on cognition during survival training. Methods.-In a cross-over design (n = 12), the effects of FD (up to 66 hours followed by 500 kcal intake over 24 hours) and SD (up to 50 hours) on cognitive variables, blood glucose, and 3-OH-butyrate were studied. Results.-Food deprivation and SD impaired attention-dependent tasks. The FD impairment of simple reaction time was independent of blood glucose levels, which were normalized by a 500 kcal intake over 24 hours while the reaction time was not. Sleep deprivation and FD impaired maze-solving performance on all variables except rule breaks, which were significantly occurring after 50 hours of SD. Delayed word recall was impaired by SD for 50 hours. On the Balloon Analogue Risk Task, SD was associated with reduced risk-taking. In a gambling task, both SD for 50 hours and FD for 66 hours were associated with a tendency to make early choices when presented with consecutive choices, but the risk-taking was not affected. Conclusions.-Sleep deprivation has multiple cognitive effects, including attention, memory, visual-spatial ability, and risk-taking. Food deprivation had no affect on risk-taking, while the other tasks were affected in a way similar to SD but were less pronounced. The FD effects on cognition did not appear to depend on blood sugar levels. The need to sleep should be prioritized in survival situations to avoid cognitive impairment.
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