title: Impaired glucose tolerance after brief heat exposure: a randomized crossover study in healthy young men.
abstract: A high demand on thermoregulatory processes may challenge homoeostasis, particularly regarding glucose regulation. This has been understudied, although it might concern millions of humans. The objective of this project was to examine the isolated and combined effects of experimental short-term mild heat exposure and metabolic level on glucoregulation. Two experimental randomized crossover studies were conducted. Ten healthy young men participated in study A, which comprises four sessions in a fasting state at two metabolic levels [rest and exercise at 60% of maximal oxygen uptake (O2) for 40 min] in two environmental temperatures (warm: 31°C and control: 22°C). Each session ended with an ad libitum meal, resulting in similar energy intake across sessions. In study B, 12 healthy young men underwent two 3 h oral glucose tolerance tests (OGTTs) in warm and control environmental temperatures. Venous blood was sampled at several time points. In study A, repeated measure ANOVAs revealed higher postprandial serum glucose and insulin levels with heat exposure. Glycaemia following the OGTT was higher in the warm temperature compared with control. The kinetics of the serum glucose response to the glucose load was also affected by the environmental temperature (temperature-by-time interaction, P=0.030), with differences between the warm and control conditions observed up to 90 min after the glucose load (all P<0.033). These studies provide evidence that heat exposure alters short-term glucoregulation. The implication of this environmental factor in the physiopathology of Type 2 diabetes has yet to be investigated.
authors.affiliation: Adaptation to Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Faure
authors.affiliation: Adaptation to Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France UMR-INSERM 1134, University of the French West Indies, Guadeloupe, France and Laboratory of Excellence GR-Ex (The red cell: from genesis to death), PRES Sorbonne Paris Cité, Paris, France.
authors.forename: Keyne
authors.initials: K
authors.lastname: Charlot
authors.affiliation: Adaptation to Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France Orthopedics and Trauma Center, Academic Hospital of Pointe-à-Pitre-Abymes, Guadeloupe, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Henri
authors.affiliation: UMR-INSERM 1134, University of the French West Indies, Guadeloupe, France and Laboratory of Excellence GR-Ex (The red cell: from genesis to death), PRES Sorbonne Paris Cité, Paris, France.
authors.forename: Marie-Dominique
authors.initials: MD
authors.lastname: Hardy-Dessources
authors.affiliation: Adaptation to Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Hue
authors.affiliation: Adaptation to Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France sophie.jonville@univ-ag.fr.
authors.forename: Sophie
authors.initials: S
authors.lastname: Antoine-Jonville
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology; D002149:Energy Intake / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005215:Fasting / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D018149:Glucose Intolerance / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D012146:Rest / Q000502:physiology; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D005947:Glucose
keywords: environment; exercise; glucoregulation; glucose; metabolism; oral glucose tolerance test