Sauna exposure leads to improved arterial compliance: Findings from a non-randomised experimental study

Abstract

Background Heat therapy has been suggested to improve cardiovascular function. However, the effects of hot sauna exposure on arterial compliance and the dynamics of blood flow and pressure have not been well documented. Thus, we investigated the short-term effects of sauna bathing on arterial stiffness and haemodynamics. Design The design was an experimental non-randomised study. Methods There were 102 asymptomatic participants (mean age, 51.9 years) who had at least one cardiovascular risk factor. Participants were exposed to a single sauna session (duration: 30 min; temperature: 73℃; humidity: 10-20%). Pulse wave velocity, augmentation index, heart rate, blood pressure, mean arterial pressure, pulse pressure, augmented pressure and left ventricular ejection time were assessed before, immediately after, and 30 min after a single sauna session. Results Sauna bathing led to reductions in pulse wave velocity, blood pressure, mean arterial pressure and left ventricular ejection time. Mean pulse wave velocity value before sauna was 9.8 m/s and decreased to 8.6 m/s immediately after sauna bathing ( p < 0.001 for difference), and was 9.0 m/s after the 30-minute recovery period ( p < 0.001 for analysis of variance). Systolic blood pressure was 137 mm Hg before sauna bathing, decreasing to 130 mm Hg after sauna ( p < 0.001), which remained sustained during the 30-minute recovery phase ( p < 0.001 for analysis of variance). After a single sauna session, diastolic blood pressure decreased from 82 to 75 mm Hg, mean arterial pressure from 99.4 to 93.6 mm Hg and left ventricular ejection time from 307 to 278 m/s ( p < 0.001 for all differences). Pulse pressure was 42.7 mm Hg before the sauna, 44.9 mm Hg immediately after the sauna, and reduced to 39.3 mm Hg after 30-minutes recovery ( p < 0.001 for analysis of variance). Heart rate increased from 65 to 81 beats/min post-sauna ( p < 0.001); there were no significant changes for augmented pressure and pulse pressure amplification. Conclusion This study shows that pulse wave velocity, systolic blood pressure, diastolic blood pressure, mean arterial pressure, left ventricular ejection time and diastolic time decreased immediately after a 30-minute sauna session. Decreases in systolic blood pressure and left ventricular ejection time were sustained during the 30-minute recovery phase.

Cardiovascular and Other Health Benefits of Sauna Bathing: A Review of the Evidence

“…4 Sauna bathing habits may have changed over time, but still a typical Finnish person has a sauna bath at least once per week, with the average habitual frequency being 2 to 3 times/wk. [5][6][7] During a sauna session, the heart rate may increase from baseline up to 120 to 150 beats/ min. There is no active function of skeletal muscles during sauna bathing, which is in contrast to the training response experienced during physical activity.…”

“…Evidence suggests that the responses produced by an ordinary sauna bath correspond to those produced by moderateor high-intensity physical activity such as walking. 32 Pathways implicated in the effects of sauna bathing on vascular disease and mortality risk include reduction in systemic BP 14 ; improvement in endothelial function [33][34][35] ; reduction in oxidative stress 36,37 and inflammation 38,39 ; beneficial modulation of the autonomic nervous system 11 ; positive alteration in levels of circulating vascular risk factors such as natriuretic peptides 40 and lipids 41,42 ; hormonal changes; improved arterial stiffness, arterial compliance, and intima media thickness 7,36,40,43,44 ; and improvement in the cardiorespiratory system 45 as well as cardiovascular function 3,4,46 (Figure 2). Indeed, these pathways are involved in the pathophysiology of chronic disease outcomes such as type 2 diabetes and CVD as well as mortality.…”

Combined Effect of Sauna Bathing and Cardiorespiratory Fitness on the Risk of Sudden Cardiac Deaths in Caucasian Men: A Long-term Prospective Cohort Study

“…9 Sauna bathing, a traditional Finnish activity which is commonly used for the purposes of pleasure, relaxation, and wellness, and becoming a popular activity in many other countries, 12,13 has been observed to be linked to several health benefits. These include improvement in the pain and symptoms associated with musculoskeletal diseases 14 ; treatment of chronic headache 15 ; improvement in CV function 16,17 and reduced risk of respiratory diseases, 18,19 hypertension, 20 and neurocognitive disease. 21 Recent long-term observational epidemiological evidence has shown that having frequent sauna baths is independently associated with a reduced risk of SCD.…”

Associations of cardiorespiratory fitness, physical activity, and BMI with arterial health in middle‐aged men and women

“…Pulse wave velocity (PWV) and augmentation index (AIx) as measures of arterial stiffness were measured before, immediately after, and 10 min after the maximal graded exercise test by a single trained researcher (EL) using a PulsePen device (DiaTecne s.r.l., Milan, Italy; http://www.pulsepen.com) which includes one tonometer and an integrated ECG unit (Lee et al., 2018, 2019). The measurement of arterial stiffness and arterial dilatation capacity followed closely established guidelines (Tomlinson, 2012; Van Bortel et al., 2012).…”