Risk factors for acute mountain sickness in travellers to Cusco, Peru: coca leaves, obesity and sex

Abstract

Background Acute mountain sickness (AMS) may occur after rapid ascents to altitudes > 2500 m. Cusco (3350 m) in Peru is a popular destination for altitude inexperienced travelers. This study aimed at evaluating the incidence and risk factors for AMS among a cohort of foreign Spanish language students in Cusco. Methods We performed a cohort study among young healthy foreign Spanish language students arriving to Cusco between 2012 and 2016. Consenting students answered an enrollment questionnaire on demographics, travel history, and intended AMS preventive behavior within 48 hours of arrival. At 4 to 5 days after enrollment participants answered a second questionnaire about actual preventive behavior before symptoms and the development of symptoms compatible with AMS during their first 48 hours in Cusco. We used the 2018 Lake Louis Scoring System (LLSS) for AMS diagnosis. Participants with headache and a score ≥ 3 were considered to have AMS. Results We enrolled 142 language students, the median age was 21 years (IQR 20–25) and 57% were female. Participants decreased physical activity (38%), increased fluid intake (34%), drank coca leaf tea (34%), took acetazolamide (16%), and acclimatized at a lower altitude (6%) to prevent AMS. Thirty nine percent had AMS. In the multivariate analysis, obesity (OR 14.45 [2.33–89.6]) and female sex (OR 4.32 [1.81–10.28]) were associated with increased risk of AMS. Taking acetazolamide (OR 0.13 [0.03–0.56) was associated with decreased AMS risk. Consumption of coca leaf tea was not associated with decreased risk of AMS. Conclusions In our cohort, AMS affected two out of five travelers. Obesity and female sex were associated with increased risk. Drinking coca leaf tea for prevention did not decrease the risk of AMS. Acetazolamide prophylaxis was associated with decreased risk of AMS.

Effects of Acute Exposure and Acclimatization to High-Altitude on Oxygen Saturation and Related Cardiorespiratory Fitness in Health and Disease

“…Exercise responses at altitude, i.e., ventilation, heart rate, and lactate concentrations were all significantly higher at comparable levels of exercise [27], indicating elevated exercise stress and cardiovascular risks in CAD patients ascending acutely to high altitude [27,28]. Importantly, those studies also demonstrated the ability of normal acclimatization in CAD patients within about 5-10 days [19,29]. De Vries and colleagues found similar changes in exercise performance and related physiological responses in CAD patients and healthy controls, who travelled from sea level to 4200 m for a 10-day acclimatization period [29].…”

Isocapnic CO2 administration stabilizes breathing and eliminates apneas during sleep in obese mice exposed to hypoxia

“…Hypoxia at high altitude is associated with major physiological distress. Obesity increases the risk of acute high altitude illness and nocturnal desaturation [9]. Unlike human SDB, in which high altitude leads to central apneas superimposed on pre-existing obstructive apneas, in DIO mice, apneas were exclusively central during all gas challenges.…”

Temporary hypoxemia at high altitude in an intensive care unit physician

“…9 Interindividual variations in the responses to altitude may be due to age, obesity, genetics, physical activity history, and exercise capacity. 10,11 These factors may cause varied symptoms, depending on the efficiency of adaptation to the demands for increased oxygen delivery. The passenger who best tolerated the high-altitude exposure, as evidenced by the higher SaO 2 and lower heart rate, was a lean, muscular Place where maximum time was spent and oxygen saturation was measured with pulse oximetry.…”