Endocrine Abstracts

Introduction: Exercise in the heat can impose significant physiological strain and may result in incapacity, illness and death from exertional heat stroke (EHS). The adrenocortical response to exercise is known to be amplified with concurrent heat stress, suggesting the potential utility of cortisol measurement in dynamic surveillance for heat intolerance. In laboratory conditions, a standard Heat Tolerance Assessment (HTA) may be used to determine thermal tolerance to exercis...

Background: Heat acclimatisation (HA) describes phenotypic changes (decreased heart rate, HR; lower core body temperature, Tc) resulting from exposure to a hot environment. Heat tolerance with HA may reflect altered adrenocortical and autonomic nervous responses to heat stress, though evidence for sympathetic downregulation is lacking. Methodological limitations to further investigation (e.g. with direct catecholamine measurement) could be overcome by assaying the catecholamin...

Background: Work in a hot environment can cause elevated core body temperature (Tc), circulatory insufficiency and death from Exertional Heat Illness (EHI). Failure to undergo successful heat acclimatisation (HA) is seen in ~5% of otherwise healthy volunteers and may lead to significant EHI, but pathways to severe illness remain poorly understood. Copeptin, a glycopeptide co-secreted with the pituitary hormone arginine vasopressin, reflects osmotic and cardiovascular stress an...

Background: Exertional heat illness (EHI) is an incapacitating and sometimes fatal phenomenon. It is associated with elevated core temperature (Tc), cardiovascular instability and the systemic inflammatory response syndrome. EHI-preventive guidelines recommend maintaining Tc ≤38 °C, an important thermoregulatory threshold above which vasomotor compensation plateaus and pronounced excursions in key pituitary and adrenal hormones occur. Copeptin, the C-terminal part o...

Background: Regulation of core body temperature (Tc) can cause significant cardiovascular strain, leading to impaired performance, incapacitation and occupational hazard during work in the heat. Where continuous Tc and heart rate (HR) monitoring is not possible (e.g. during firefighting or on military operations), safer working could result from intermittent sampling of an integrated measure of physiological strain.Aims: To assess the relationship betwee...