Repeated infrared Sauna Bathing in Adults With Obesity and Pulse Wave Velocity

Abstract

Introduction: Obesity is associated with elevated cardiovascular disease risk due to increased arterial stiffness. Passive heat therapy has been shown to reduce arterial stiffness, which can be determined by pulse wave velocity (PWV). Previous reports have shown that heat therapy can reduce arterial stiffness, however it is unknown whether repeated far-infrared sauna bathing is also effective at targeting arterial stiffness in individuals with obesity. Purpose: To test the hypothesis that repeated far-infrared sauna bathing would reduce PWV in individuals with obesity. Methods: We recruited 5 individuals (4 men, 1 woman, age: 34±10 years) with obesity (BMI 35.5±3.8 kg/m2) who were randomly assigned to the heat therapy (n=3) or time control (n=2) groups. The heat therapy group completed 30 far-infrared sauna sessions (54±6°C) for 43±4 minutes within 9 weeks. The time control group maintained activities of daily living. Arterial stiffness as quantified by carotid-femoral PWV via applanation tonometry (SphygmoCor® XCEL). PWV was measured before heating (PRE), after 15 sauna sessions or 4-5 weeks (MID), and after 30 sauna sessions or 9-10 weeks (POST). Results: There was no effect of time (p = 0.4605), group (p = 0.3817), or group x time interaction (p = 0.3412) for pulse wave velocity at PRE vs. MID vs. POST for Control (6.7±0.9 vs. 6.2±0.2 vs. 6.5±0.6 m/s) or Heat (7.6±1.5 vs. 7.7±1.6 vs. 8.0±2.1 m/s). Conclusions: These data indicate that 30 sessions of far-infrared sauna sessions did not reduce arterial stiffness in individuals with obesity.