Hot water immersion acutely increases postprandial glucose concentrations. Issue 20 (22nd October 2019)

• Record Type: Journal Article
• Authors: Leicht, Christof A.; James, Lewis J.; Briscoe, Jane H. B.; Hoekstra, Sven P.
• Is Part Of: Physiological reports. Volume 7:Issue 20(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-10-22
• Subjects: Glycemic control -- hot water therapy -- hyperthermia -- passive heating -- temperature; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.14223
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: Chronic hot water immersion (HWI) confers health benefits, including a reduction in fasting blood glucose concentration. Here we investigate acute glycemic control immediately after HWI. Ten participants (age: 25 ± 6 years, body mass: 84 ± 14 kg, height 1.85 ± 0.09 m) were immersed in water (39°C) to the neck (HWI) or sat at room temperature (CON) for 60 min. One hour afterward they underwent an oral glucose tolerance test (OGTT), with blood collected before and after HWI/CON and during the 2 h OGTT. Glucose incremental area under the curve (iAUC) during the OGTT was higher for HWI (HWI 233 ± 88, CON 156 ± 79 mmol·L −1 ·2 h, P = 0.02). Insulin iAUC did not differ between conditions (HWI 4309 ± 3660, CON 3893 ± 3031 mU·L −1 ·2 h, P = 0.32). Core temperature increased to 38.6 ± 0.2°C during HWI, but was similar between trials during the OGTT (HWI 37.0 ± 0.2, CON 36.9 ± 0.4°C, P = 0.34). Directly following HWI, plasma average adrenaline and growth hormone concentrations increased 2.7 and 10.7‐fold, respectively ( P < 0.001). Plasma glucagon‐like peptide‐1, peptide YY, and acylated ghrelin concentrations were not different between trials during the OGTT ( P > 0.11). In conclusion, HWI increased postprandial glucose concentration to an OGTT, which was accompanied by acute elevations of stress hormones following HWI. The altered glycemic control appears to be unrelated to changes in gut hormones during the OGTT. Abstract : We report higher postprandial blood glucose concentrations after 60 min of hot water immersion (HWI) at 39°C when compared with resting control. The postprandial gut hormone and hunger responses do not appear to be related to the differential glucose response as they were unaffected by HWI.