Mental but no bio-physiological long-term habituation to repeated social stress: A study on soldiers and the influence of mission abroad.

Soldiers regularly participate in missions abroad and subjectively adapt to this situation. However, they have an increased lifetime cardiovascular risk compared to other occupational groups. To test the hypothesis that foreign deployment results in different stress habituation patterns, we investigated long-term psychological and bio-physiological stress responses to a repeated social stress task in healthy soldiers with and without foreign deployment. Ninety-one female and male soldiers from the BEST study (German armed forces deployment and stress) participated three times in the Trier Social Stress Test for groups (TSST-G) prior to, 6-8 weeks after and 1 year after the mission abroad and were compared to a control group without foreign deployment during the study period. They completed the State-Trait-Anxiety Inventory scale (STAI), the Primary Appraisal Secondary Appraisal questionnaire (PASA) and the Multidimensional Mood State Questionnaire (MDBF). Salivary cortisol and α-amylase, blood pressure, heart rate and heart rate variability were determined. Soldiers showed mental habituation over the three times with a significant decrease after the TSST-G in anxiousness (STAI) and cognitive stress appraisal (PASA), they were calmer and reported better mood (MDBF). Prior to the social stress part, the mood (MDBF) declined significantly. None of the biological and physiological markers showed any adaptation to the TSST-G. Mission abroad did not significantly influence any measured psychobiological marker when compared to soldiers without foreign deployment. Foreign deployment does not result in alterations in psychobiological social stress response patterns over 1 year after mission abroad which indicates that adaptation to acute social stress is highly maintained in healthy soldiers. The discrepancy between subjective perception and objective stress response has numerous clinical implications and should receive more attention.

Structural Equation Modeling of a Global Stress Index in Healthy Soldiers.

Accumulation of stress is a prognostic trigger for cardiovascular disease. Classical scores for cardiovascular risk estimation typically do not consider psychosocial stress. The aim of this study was to develop a global stress index (GSI) from healthy participants by combining individual measures of acute and chronic stress from childhood to adult life. One-hundred and ninety-two female and male soldiers completed the Perceived Stress Scale (PSS4), Trier Inventory for Chronic Stress (TICS), Hospital Anxiety and Depression Scale (HADS), Childhood Trauma Questionnaire (CTQ), Posttraumatic Diagnostic Scale Checklist (PDS), and the Deployment Risk and Resilience Inventory (DRRI-2). The underlying structure for the GSI was examined through structural equation modeling. The final hierarchical multilevel model revealed fair fit by taking modification indices into account. The highest order had a g-factor called the GSI. On a second level the latent variables stress, HADS and CTQ were directly loading on the GSI. A third level with the six CTQ subscales was implemented. On the lowest hierarchical level all manifest variables and the DRRI-2/PDS sum scores were located. The presented GSI serves as a valuable and individual stress profile for soldiers and could potentially complement classical cardiovascular risk factors.

Social Stress-Induced Oxidative DNA Damage Is Related to Prospective Cardiovascular Risk.

Psychosocial stress increases cardiovascular risk, which coincides with enhanced oxidative DNA damage. Increased sympathetic tone-related catecholamine release causes oxidative stress, which contributes to catecholamine-related cardiotoxicity. Therefore, we tested the hypothesis whether acute psychosocial stress induces oxidative DNA damage, its degree being related to the cardiovascular risk profile and depending on the sympathetic stress response. After assessment of the prospective cardiovascular Münster score (PROCAM) to determine the risk of acute myocardial infarction, 83 male and 12 female healthy volunteers underwent the Trier social stress test for groups (TSST-G). Heart rate variability was quantified by measuring the standard deviation (SDNN) and root mean square of successive differences (RMSSD) between normal-to-normal inter-beat intervals. Salivary α-amylase (sAA) activity was assessed as a surrogate for noradrenaline plasma concentrations. Oxidative DNA damage was determined using whole-blood single-cell gel electrophoresis ("tail moment" in the "comet assay"). A total of 33 subjects presented with a prospective risk of myocardial infarction (risk+) vs. 59 subjects without risk (risk-). The TSST-G stress significantly increased blood pressure, heart rate, and sAA in both groups, while oxidative DNA damage was only increased in the risk+ group. Immediately after the TSST-G, the "tail moment" showed significant inverse linear relations with both SDNN and RMSSD. Acute psychosocial stress may cause oxidative DNA damage, the degree of which is directly related to the individual cardiovascular risk profile and depends on the stress-induced increase in the sympathetic tone.

The challenge of military surgical education.

Now that field hospitals and rescue stations have been provided with state-of-the-art equipment, it is important to tailor the medical qualifications of military surgeons to the specific requirements of missions outside Germany. The objective of this article is to provide guidelines for a new training model. Einsatzchirurgie is defined as surgical treatment provided under restricted conditions in an unfamiliar environment. Its purpose is, first and foremost, to provide emergency treatment. The spectrum of Einsatzchirurgie, however, also encompasses maximum medical treatment on a case-by-case basis and emergency surgical treatment in a mass casualty situation. Training, for example, may consist of a 6-year basic training course in surgery followed by specialist training in abdominal surgery, traumatology, and courses in further disciplines--e.g., urology, gynecology, or neurosurgery. In addition to the qualifications required by the Landesärztekammem (professional organizations of German physicians at the federal countries level), military surgeons who are to become senior medical officers should also be qualified to provide immediate non-surgical emergency care. In these times, the education of military surgeons remains a great challenge. Motivation to work as a surgeon in the armed forces with multiple deployments during the career requires enthusiasm and professionalism. The attractiveness of the training institution and the home hospital is key for successful work as a military surgeon.

Proinflammatory and antiinflammatory cytokines after cardiac operation: different cellular sources at different times.

BACKGROUND: Cardiac operation produces substantial alterations within the immune system, which possibly predispose postoperative complications. However, the interplay between proinflammatory and antiinflammatory reactions and the cells involved in this process are not completely clear. Therefore, we investigated serum levels, as well as synthesis patterns, of proinflammatory and antiinflammatory cytokines. METHODS: Serum levels and production of interleukin (IL) IL-5, IL-6, IL-10, tumor necrosis factor-alpha, and interferon-gamma, using a mixed cell culture, (ie, monocytes, macrophages, and lymphocytes), as well as a purified lymphocyte culture were measured preoperatively (day 0), on postoperative day 1, on postoperative day 3, and on postoperative day 5 in 25 patients undergoing cardiac operations and were compared with 10 healthy volunteers. RESULTS: Serum level and mixed cell culture, production of IL-6, tumor necrosis factor-alpha, and IL-10 increased on postoperative day 1, but decreased in lymphocyte culture. Base line values were reached on postoperative day 5. Interferon-gamma serum levels remained unchanged, whereas IL-5 serum levels increased on postoperative days 3 and 5. Cell culture synthesis showed a significant suppression for both mediators in both cell cultures, which returned to baseline on postoperative day 3 in mixed cell culture. Interferon-gamma production by lymphocytes was suppressed until postoperative day 5, whereas IL-5 returned to preoperative values on postoperative day 5. CONCLUSIONS: Cardiac operation induces a biphasic immune response. The first phase (postoperative day 1) appears to represent the proinflammatory and antiinflammatory reaction of the innate immune system returning to base line on postoperative day 3. The second phase (postoperative day 5) may represent the response of the adaptive immune system and is characterized by an antiinflammatory type of reaction. This may explain why the systemic inflammatory response occurs immediately after cardiac operation, whereas infections occur later.