Uroflowmetry and Altitude Hypoxia: A Report from Healthy Italian Trekkers and Nepali Porters During Himalayan Expedition

Feeding Your Himalayan Expedition: Nutritional Signatures and Body Composition Adaptations of Trekkers and Porters

High-altitude exposure leads to many physiological challenges, such as weight loss and dehydration. However, little attention has been posed to the role of nutrition and ethnic differences. Aiming to fulfill this gap, five Italian trekkers and seven Nepalese porters, all males, recorded their diet in diaries during a Himalayan expedition (19 days), and the average daily intake of micro and macro-nutrients were calculated. Bioimpedance analysis was performed five times during the trek; muscle ultrasound was performed before and after the expedition, only for the Italians. The Nepalese group consumed a lot of rice and only Italians consumed cheese. Water intake was slightly over 3000 g/d for both groups. Nepalese diet had a higher density of dietary fibre and lower density of riboflavin, vitamins A, K, and B12. Intake of calcium was lower than recommended levels. Body mass index, waist circumference, fat-free mass, and total body water decreased in both groups, whereas resistance (Rz) increased. Italians reactance (Xc) increased at day 9, whereas that of Nepalese occurred at days 5, 9, and 16. The cross-sectional area of the Vastus lateralis was reduced after the expedition. Specific nutritional and food-related risk factors guidance is needed for diverse expedition groups. Loss of muscle mass and balance of fluids both deserve a particular focus as concerns altitude expeditions.

Effects of Physical Activity at High Altitude on Hormonal Profiles in Foreign Trekkers and Indigenous Nepalese Porters

Altitude exposure affects hormonal homeostasis, but the adaptation of different populations is still not finely defined. This study aims to compare the mid-term effects of combining physical activity and altitude hypoxia on hormonal profiles in foreign trekkers coming from Italy versus indigenous Nepalese porters during a Himalayan trek. Participants (6 Italians and 6 Nepalese) completed a 300 km distance in 19 days of an accumulated altitude difference of 16,000 m, with an average daily walk of 6 h. The effect of high altitude on hormonal pathways was assessed by collecting blood samples the day before the expedition and the day after its completion. Foreign trekkers had an additional follow-up sample collected after 10 days. The findings revealed a different adaptation of thyroidal and gonadal axes to mid-term strenuous physical activity combined with high-altitude hypobaric hypoxia. The thyroid function shifted to the protective mechanism of low free triiodothyronine (FT3), whereas the gonadal axis was suppressed. The Italian trekkers and Nepalese porters had lower total testosterone and 17-β-estradiol levels after the expedition. At the follow-up, the Italians had increased testosterone values. Prolactin secretion decreased in the Italians but increased in the Nepalese. We conclude that exposure to high-altitude affects the hormonal axes. The effect seems notably pronounced for the hypothalamus-pituitary gonadal axis, suppressed after high-altitude exposure.