Aim: Heat therapy is a promising strategy to improve cardiometabolic health. This study evaluated the acute physiological responses to hot water immersion in adults with type 2 diabetes mellitus (T2DM). Methods: On separate days in randomized order, 13 adults with T2DM (8 males/5 females, 62 ± 12 yrs, BMI: 30.1 ± 4.6 kg/m2) were immersed in thermoneutral (34°C, 90 minutes) or hot (41°C, core temperature ≥38.5°C for 60 minutes) water. Insulin sensitivity was quantified via the minimal oral model during an oral glucose tolerance test (OGTT) performed 60 minutes after immersion. Brachial artery flow-mediated dilation (FMD) and reactive hyperemia were evaluated before and 40 minutes after immersion. Blood samples were drawn to quantify protein concentrations and mRNA levels of HSP70 and 90, and circulating concentrations of cytokines. Results: Relative to thermoneutral water immersion, hot water immersion increased core temperature (+1.66°C [+1.47, +1.87], P<0.01), heart rate (+34 bpm [+24, +44], P<0.01), antegrade shear rate (+96 s-1 [+57, +134], P<0.01), and IL-6 (+1.38 pg/mL [+0.31, +2.45], P=0.01). Hot water immersion did not exert an acute change in insulin sensitivity (-0.3 dl/kg/min/μU/ml [-0.9, +0.2], P=0.18), FMD (-1.0% [-3.6, +1.6], P=0.56), peak (+0.36 mL/min/mmHg [-0.71, +1.43], P=0.64) and total (+0.11 mL/min/mmHg x min [-0.46, +0.68], P=0.87) reactive hyperemia. There was also no change in eHSP70 (P=0.64), iHSP70 (P=0.06), eHSP90 (P=0.80), iHSP90 (P=0.51), IL1-RA (P=0.11), GLP-1 (P=0.59) and NFkB (P=0.56) after hot water immersion. Conclusion: The physiological responses elicited by hot water immersion do not acutely improve markers of cardiometabolic function in adults with T2DM.

PurposeThe benefits of exercise on vascular health are inconsistent in postmenopausal females. We investigated if blood pressure and markers of vascular function differ between physically active early post- and late premenopausal females.MethodsWe performed a cross-sectional comparison of 24-h blood pressure, brachial artery flow-mediated dilation, microvascular reactivity (reactive hyperemia), carotid–femoral pulse wave velocity, and cardiac baroreflex sensitivity between physically active late premenopausal (n = 16, 48 ± 2 yr) and early postmenopausal (n = 14, 53 ± 2 yr) females.ResultsPhysical activity level was similar between premenopausal (490 ± 214 min·wk−1) and postmenopausal (550 ± 303 min·wk−1) females (P = 0.868). Brachial artery flow-mediated dilation (pre, 4.6 ± 3.9, vs post, 4.7% ± 2.2%; P = 0.724), 24-h systolic (+5 mm Hg, 95% confidence interval [CI] = –1 to +10, P = 0.972) and diastolic (+4 mm Hg, 95% CI = –1 to +9, P = 0.655) blood pressures, total reactive hyperemia (pre, 1.2 ± 0.5, vs post, 1.0 ± 0.5 mL·mm Hg−1; P = 0.479), carotid–femoral pulse wave velocity (pre, 7.9 ± 1.7, vs post, 8.1 ± 1.8 m·s−1; P = 0.477), and cardiac baroreflex sensitivity (−8 ms·mm Hg−1, 95% CI = –20.55 to 4.62, P = 0.249) did not differ between groups. By contrast, peak reactive hyperemia (−0.36 mL·min−1⋅mm Hg−1, 95% CI = –0.87 to +0.15, P = 0.009) was lower in postmenopausal females.ConclusionsThese results suggest that blood pressure and markers of vascular function do not differ between physically active late pre- and early postmenopausal females.