Thermoregulatory Responses Are Attenuated after Fructose but Not Glucose Intake.

• Autores: Akina Suzuki, Toshiaki Miyagawa, Kazunobu Okazaki, Daiki Imai, Ryosuke Takeda, Nooshin Naghavi, Hisayo Yokoyama
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 46, Nº. 7, 2014, págs. 1452-1461
• Idioma: inglés
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• Resumen

  • AB Purpose: We examined whether plasma hyperosmolality induced by oral monosaccharide intake attenuated thermoregulatory responses and whether the responses were different between fructose and glucose. Methods: Ten healthy young subjects performed three trials in a sitting position in an artificial climate chamber (ambient temperature, 28[degrees]C; relative humidity, 40%). After resting for 10 min, the subjects drank 300 mL of water alone (control), or 300 mL of water supplemented with 75 g fructose or 75 g glucose. Twenty minutes later, they were heated passively by immersing the lower legs in water at 42[degrees]C for 60 min. Plasma osmolality (Posm), sodium ([Na+]p) and insulin concentrations ([Ins]p), and percent change in plasma volume (%[DELTA]PV) were measured, and esophageal temperature (Tes) thresholds for cutaneous vasodilation (THCVC) and sweating (THSR) at the forearm were determined. Results: Posm was significantly increased by fructose and glucose intake compared with water alone, although %[DELTA]PV and [Na+]p were not significantly different among the three trials. [Ins]p was significantly higher after glucose intake than after fructose or water alone. THCVC and THSR were significantly higher after fructose intake than after glucose intake, which showed similar values to water intake. Conclusions: These results suggest that the Tes threshold for thermoregulation is elevated after fructose intake, indicating the attenuation of thermoregulatory responses, whereas it is not attenuated after glucose intake. These results provide a novel insight to better determine the carbohydrate component of oral rehydration fluids for preventing dehydration and/or heat disorders