Body Composition and Endocrine Adaptations To High Altitude Trekking in the Himalayas

Long-term exposure to high altitude causes
adaptive changes in several blood biochemical
markers along with a marked body mass
reduction involving both the lean and fat
components. The aim of this study was to
evaluate the impact of extended physical
strain, due to extensive trekking at high altitude, on body composition, selected
biomarkers in the blood, and the protective
role of a high-protein diet in muscle dysfunction. We found that physical strain at high
altitude caused a significant reduction in
body mass and body fat, with a concomitant
increase in the cross-sectional area of thigh
muscles and an unchanged total lean body
mass. Further, we found reductions in plasma
leptin and homocysteine, while myoglobin,
insulin, and C-reactive protein significantly
increased. Creatine kinase, lactate dehydrogenase, and leptin normalized per body fat were
unchanged. These findings demonstrate that
high-altitude hypoxia, involving extended
physical effort, has an impact on muscle function and body composition, facilitating
sarcopenia and affecting body mass and fat
distribution. It also activates
pro-inflammatory metabolic pathways in
response to muscular distress. These changes
can be mitigated by a provision of a highprotein diet.