Circadian influences on clinical values in man

Area of Science:

• Chronobiology
• Human Physiology
• Military Medicine

Background:

• Understanding circadian rhythms is crucial for assessing physiological stability.
• Previous research has not fully elucidated the impact of acute stress on circadian patterns in young, healthy populations.

Purpose of the Study:

• To investigate the circadian patterns of various clinical parameters in young, healthy soldiers.
• To determine the stability of these rhythms under different examination conditions.
• To assess the influence of acute stress on circadian variability.

Main Methods:

• Continuous monitoring of 109 young, healthy soldiers.
• Analysis of circadian patterns for erythrocytes, hematocrit, creatinine, cortisol, leukocytes, blood glucose, and body temperature.
• Evaluation of rhythm stability through longitudinal and cross-sectional examinations.

Main Results:

• Erythrocytes, hematocrit, creatinine, and cortisol demonstrated highly stable circadian rhythms.
• Leukocytes, blood glucose, and body temperature exhibited significant variability.
• Stressors, including hospital-like environments and blood sampling pain, markedly altered the rhythmic patterns of leukocytes, blood glucose, and body temperature.

Conclusions:

• Certain physiological parameters, such as erythrocytes, hematocrit, creatinine, and cortisol, possess robust circadian stability in healthy young adults.
• Acute psychological and physical stressors can significantly disrupt the circadian rhythms of other parameters, including leukocytes, blood glucose, and body temperature.
• These findings highlight the sensitivity of specific circadian rhythms to environmental and physiological challenges in a military context.