T-Allele Carriers of Mono Carboxylate Transporter One Gene Polymorphism rs1049434 Demonstrate Altered Substrate Metabolization during Exhaustive Exercise.

BACKGROUND: Polymorphism rs1049434 characterizes the nonsynonymous exchange of adenosine (A) by thymidine (T) in the gene for monocarboxylate transporter 1 (MCT1). We tested whether T-allele carriers of rs1049434 demonstrate increased accumulation of markers of metabolic strain. METHODS: Physically active, healthy, young male subjects (n = 22) conducted a power-matched one-legged cycling exercise to exhaustion. Metabolic substrates in capillary blood, selected metabolic compounds, and indices for the slow oxidative phenotype of vastus lateralis muscle were quantified in samples collected before and after exercise. The genotypes of the rs1049434 polymorphism were determined with polymerase chain reactions. RESULTS: One-legged exercise affected the concentration of muscle metabolites entering the tricarboxylic acid cycle, such as acetyl-co-enzyme A (+448%) and acetyl-L-carnitine (+548%), muscle glycogen (-59%), and adenosine monophosphate (-39%), 30 min post-exercise. Exercise-related variability in the muscular concentration of glycogen, long-chain acyl co-enzyme As and a triglyceride, nicotinamide adenine dinucleotide (NADH), and adenosine monophosphate (AMP) interacted with rs1049434. T-allele carriers demonstrated a 39% lesser reduction in glycogen after exercise than non-carriers when NADH increased only in the non-carriers. Muscle lactate concentration was 150% higher, blood triacyl-glyceride concentration was 53% lower, and slow fiber percentage was 20% lower in T-allele carriers. DISCUSSION: The observations suggest a higher anaerobic glycolytic strain during exhaustive exercise and a lowered lipid handling in T-allele non-carriers.

Stranded because of exhaustion while high-altitude mountaineering in the Swiss Alps: a retrospective nationwide study.

Fortunately, fatal accidents while high-altitude mountaineering have decreased in recent years, but the number of emergencies has increased. These nonfatal emergencies might represent situations where alpinists are stranded (emergencies in which alpinists are no longer able to continue their tour on their own because of, for example, exhaustion, equipment problems, or weather). We analyzed 4596 cases of high-altitude-mountaineering emergencies in the period 2009 to 2020 from the SAC (Swiss Alpine Club) emergency registry. In total, 1951 cases (41.6%) were due to being stranded, 1348 cases were due to falls (28.7%), and 352 cases were due to illness (7.5%); these were the three most common classes. In cases of being stranded, 90% of alpinists were uninjured or not seriously injured. In addition, we found only eight fatal cases. More than 50% of cases occurred while ascending a summit above 4000 m. The main causes of becoming stranded were exhaustion and weather changes. These findings suggest that alpinists contact rescue organizations before experiencing serious troubles; these situations thus present risks and dangers both to those stranded and to emergency services. Since exhaustion and weather changes are the two main causes, adequate preparation and tour planning may help prevent such emergencies.

[Analysis of Cardiovascular Risk Factors in Young Backcountry Skiers in the Gotthard Region]. / Analyse kardiovaskulärer Risikofaktoren bei jugendlichen Skitourengängern im Gotthardgebiet.

Background and Objectives Although the frequency of cardiovascular events, especially the end manifestation of myocardial infarction, has decreased in recent years, cardiovascular disease continues to be one of the most frequent illnesses. Also it is known that the cardiac system sustains more stress at high altitudes than it does at intermediate altitudes. This leads to the question if young alpinists should undergo cardiac evaluation before setting out for a trip to the Himalayas or the Andes Mountains. Material and Methods This study analysed 86 young male, active backcountry skiers (26 ±â€Š8.9 years) in the Swiss Alps (Gotthard area) for cardiovascular risk factors (diabetes mellitus, obesity, smoking, lack of physical activity) and cardiovascular diseases (coronary heart disease, myocardial infarction, valvular heart disease, heart rhythm disorders and hypertension) with a view to recommendations regarding the value of prior cardiac evaluation. Results In the sample of backcountry skiers in the Gotthard area, only a small proportion of participants had risk factors. Especially smoking - the most important risk factor - was rare. The general amount of physical activity with an average of almost ten hours a week was high in the analysed sample. Nevertheless, seven young backcountry skiers suffered from hypertension, and there was one case of a valvular disease and one case of an arrhythmogenic disease. Conclusions Based on these results, with a prevalence of more than one percent, prior cardiac evaluation seems to be advisable for skiers with risk factors if altitudes change from intermediate levels (2000 to 3000 meters) to the High Alps, and generally when mountaineering is practiced in high altitude (Himalayas, Andes Mountains) due to the decrease in oxygen partial pressure.