PMID- 33411640 OWN - NLM STAT- MEDLINE DCOM- 20210629 LR - 20210629 IS - 1522-1601 (Electronic) IS - 0161-7567 (Linking) VI - 130 IP - 4 DP - 2021 Apr 1 TI - Timing of acute passive heating on glucose tolerance and blood pressure in people with type 2 diabetes: a randomized, balanced crossover, control trial. PG - 1093-1105 LID - 10.1152/japplphysiol.00747.2020 [doi] AB - Type 2 diabetes mellitus (T2DM) is characterized by chronic hyperglycemia and progressive insulin resistance, leading to macro and microvascular dysfunction. Passive heating has potential to improve glucose homeostasis and act as an exercise mimetic. We assessed the effect of acute passive heating before or during an oral glucose tolerance test (OGTT) in people with T2DM. Twelve people with T2DM were randomly assigned to the following three conditions: 1) 3-h OGTT (control), 2) 1-h passive heating (40 degrees C water) 30 min before an OGTT (HOT-OGTT), and 3) 1-h passive heating (40 degrees C water) 30 min after commencing an OGTT (OGTT-HOT). Blood glucose concentration, insulin sensitivity, extracellular heat shock protein 70 (eHSP70), total energy expenditure (TEE), heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were recorded. Passive heating did not alter blood glucose concentration [control: 1,677 (386) arbitrary units (AU), HOT-OGTT: 1,797 (340) AU, and OGTT-HOT: 1,662 (364) AU, P = 0.28], insulin sensitivity (P = 0.15), or SBP (P = 0.18) but did increase eHSP70 concentration in both heating conditions [control: 203.48 (110.81) pg.mL(-1); HOT-OGTT: 402.47 (79.02) pg.mL(-1); and OGTT-HOT: 310.00 (60.53) pg.mL(-1), P < 0.001], increased TEE (via fat oxidation) in the OGTT-HOT condition [control: 263 (33) kcal, HOT-OGTT: 278 (40) kcal, and OGTT-HOT: 304 (38) kcal, P = 0.001], increased HR in both heating conditions (P < 0.001), and reduced DBP in the OGTT-HOT condition (P < 0.01). Passive heating in close proximity to a glucose challenge does not alter glucose tolerance but does increase eHSP70 concentration and TEE and reduce blood pressure in people with T2DM.NEW & NOTEWORTHY This is the first study to investigate the timing of acute passive heating on glucose tolerance and extracellular heat shock protein 70 concentration ([eHSP70]) in people with type 2 diabetes. The principal novel findings from this study were that both passive heating conditions: 1) did not reduce the area under the curve or peak blood glucose concentration, 2) elevated heart rate, and 3) increased [eHSP70], which was blunted by glucose ingestion, while passive heating following glucose ingestion, 4) increased total energy expenditure, and 5) reduced diastolic blood pressure. FAU - James, Thomas J AU - James TJ AUID- ORCID: 0000-0003-1470-9400 AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. AD - Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, United Kingdom. FAU - Corbett, Jo AU - Corbett J AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Cummings, Michael AU - Cummings M AD - Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, United Kingdom. FAU - Allard, Sharon AU - Allard S AD - Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, United Kingdom. FAU - Young, John S AU - Young JS AUID- ORCID: 0000-0002-2711-9701 AD - School of Pharmacy and Biomedical Sciences, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Towse, Jonathan AU - Towse J AD - School of Pharmacy and Biomedical Sciences, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Carey-Jones, Kathryn AU - Carey-Jones K AD - School of Biological Sciences, Faculty of Science and Health, University of Portsmouth, United Kingdom. AD - Oaks Healthcare, Cowplain Family Practice, Waterlooville, United Kingdom. FAU - Eglin, Clare AU - Eglin C AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Hopkins, Billy AU - Hopkins B AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Morgan, Connor AU - Morgan C AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Tipton, Michael AU - Tipton M AUID- ORCID: 0000-0002-7928-8451 AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. FAU - Saynor, Zoe L AU - Saynor ZL AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. AD - Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, United Kingdom. FAU - Shepherd, Anthony I AU - Shepherd AI AUID- ORCID: 0000-0001-6392-7944 AD - School of Sport, Health and Exercise Science, Faculty of Science and Health, University of Portsmouth, United Kingdom. AD - Diabetes and Endocrinology Department, Portsmouth Hospitals University NHS Trust, Portsmouth, United Kingdom. LA - eng PT - Journal Article PT - Randomized Controlled Trial PT - Research Support, Non-U.S. Gov't DEP - 20210107 PL - United States TA - J Appl Physiol (1985) JT - Journal of applied physiology (Bethesda, Md. : 1985) JID - 8502536 RN - 0 (Blood Glucose) RN - 0 (Insulin) RN - IY9XDZ35W2 (Glucose) SB - IM MH - Blood Glucose MH - Blood Pressure MH - *Diabetes Mellitus, Type 2 MH - Glucose MH - Heating MH - Humans MH - Insulin MH - *Insulin Resistance OTO - NOTNLM OT - glucose OT - hot water OT - insulin OT - insulin sensitivity OT - metabolic EDAT- 2021/01/08 06:00 MHDA- 2021/06/30 06:00 CRDT- 2021/01/07 17:13 PHST- 2021/01/08 06:00 [pubmed] PHST- 2021/06/30 06:00 [medline] PHST- 2021/01/07 17:13 [entrez] AID - 10.1152/japplphysiol.00747.2020 [doi] PST - ppublish SO - J Appl Physiol (1985). 2021 Apr 1;130(4):1093-1105. doi: 10.1152/japplphysiol.00747.2020. Epub 2021 Jan 7.