RÉSUMÉ
Background: Extreme environments are inherently stressful and are characterized by a variety of physicaland psychosocial stressors, including, but not limited to, isolation, confinement, social tensions, minimalpossibility of medical evacuation, boredom, monotony, and danger. Previous research studies recommend adaptation to the environment to maintain optimal function and remain healthy. Different interventions have been tried in the past for effective management of stress. Yoga practices have beenshown to be beneficial for coping with stress and enhance quality of life, sleep and immune status.Objective: The current article describes preparation of a Yoga module for better management of stressorsin extreme environmental condition of Antarctica.Materials and methods: A Yoga module was designed based on the traditional and contemporary yogaliterature as well as published studies. The Yoga module was sent for validation to forty experts of whichthirty responded.Results: Experts (n ¼ 30) gave their opinion on the usefulness of the yoga module. In total 29 out of 30practices were retained. The average content validity ratio and intra class correlation of the entiremodule was 0.89 & 0.78 respectively.Conclusion: A specific yoga module for coping and facilitating adaptation in Antarctica was designed andvalidated. This module was used in the 35th Indian Scientific expedition to Antarctica, and experimentsare underway to understand the efficacy and utility of Yoga on psychological stress, sleep, serum biomarkers and gene expression. Further outcomes shall provide the efficacy and utility of this module inAntarctic environments.© 2018 The Authors. Published by Elsevier B.V. on behalf of Institute of Transdisciplinary Health Sciencesand Technology and World Ayurveda Foundation. This is an open access article under the CC BY-NC-NDlicense (http://creativecommons.org/licenses/by-nc-nd/4.0/)
RÉSUMÉ
Background & objectives: Ascent to high altitude has been reported to cause hippocampal atrophy and cognitive impairment in mountaineers. We assessed the cognitive performance and probable occurrence of mild cognitive impairment (MCI) in acclimatized lowlanders (ALL) staying at altitudes above 4,300 m for duration above 12 months and validated a multi-domain cognitive screening test (MDCST) for future demographic studies on MCI. Methods: Following evaluation of sensitivity and correlation of the newly developed MDCST battery with Mini Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) scores on a group of 28 individuals, the MDCST battery was validated on a population of 843 ALL staying at high altitude MSL >4,300 m and 862 subjects staying at MSL <230 m. EEG recordings were performed on 840 ALL staying at altitudes above 4,300 m and 743 control subjects staying at MSL <230 m. Results: Percentage prevalence of MCI was 4.18 per cent in the ALL population as assessed by MMSE while that of the LL population was <0.42 per cent. The percentage prevalence of MCI based on calculations from the MDCST scores was 12.4 per cent in the ALL population as compared to 1.19 per cent in the LL population. Decrease in alpha wave amplitude at the T3 and T4 sources in MCI subjects was observed in LL group while there was an increase in amplitude for alpha wave in these regions in the ALL groups. Domain specific MDCST showed decline in immediate recall, procedural memory and mind body co-ordination which was negligible in the LL population. Interpretation & conclusions: MDCST exhibited excellent psychometric properties in terms of sensitivity, and test-retest reliability qualifying it to be used as a more effective cognitive measure for assessment of MCI in demographic studies in comparison to traditional measures. Our findings also showed increased prevalence of MCI in ALL population staying for longer durations at high altitude which is neurophysiologically distinct from MCI leading to Alzheimer's disease.
Sujet(s)
Altitude/effets indésirables , Altitude/physiologie , Atrophie/diagnostic , Atrophie/étiologie , Hippocampe/anatomopathologie , Humains , Dysfonctionnement cognitif/diagnostic , Dysfonctionnement cognitif/psychologie , Alpinisme/effets indésirables , Alpinisme/physiologie , Tests neuropsychologiques/méthodes , Psychométrie/méthodesRÉSUMÉ
BACKGROUND & OBJECTIVES: Several physiological changes affecting physical fitness occur in humans whenever they are exposed to extremes of environments such as heat, cold and high altitude (HA). The present study was undertaken to evaluate effect of stay in desert and HA on physical fitness and body composition of physically active individuals. METHODS: Study was conducted on three groups of male soldiers (n=30 in each group) at different climatic conditions i.e., temperate (plains of north India), hot desert (Rajasthan), and HA (3600 m) in Western Himalayas. Subjects were acclimatized to hot and HA environments and had similar BMI (body mass index). Body fat, lean body mass, haemoglobin levels were determined along with, blood pressure and physical fitness index (PFI). RESULTS: The body fat of subjects at temperate, desert and HA was found to be 15.4, 12.8 and 16.9 per cent respectively. The resting heart rate and blood pressure were higher in altitude group in comparison to others. PFI score of volunteers at temperate, desert and HA were found to be 97.4 +/- 10.3, 92.4+/- 14.4 and 83.8 +/- 6.2 respectively. INTERPRETATION & CONCLUSION: A combination of different factors i.e., higher resting pulse rate, increased blood pressure and body fat may be responsible for lower PFI at HA. The observed differences in body fat content of different groups could be an adaptive feature to the environment.