Sauna bathing reduces the risk of venous thromboembolism: a prospective cohort study.

Emerging evidence suggests there is an inverse and independent association between sauna bathing and arterial thrombotic disease. However, the potential association between sauna bathing and venous thromboembolism (VTE) has not yet been investigated. We aimed to assess the prospective association between frequency of sauna bathing and the risk of VTE. Baseline sauna bathing habits were assessed in 2242 men aged 42-61 years without a history of VTE in the Kuopio Ischemic Heart Disease prospective cohort. Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for VTE. During a median follow-up of 24.9 years, 146 (6.5%) incident VTE events were recorded. In age-adjusted analyses, the HRs 95% (CIs) of VTE were 0.67 (0.47-0.96) and 0.95 (0.53-1.70) for participants who had 2-3 and ≥ 4 sauna sessions per week respectively compared with participants who had ≤ 1 sauna session per week. After further adjustment for several established risk factors including lifestyle factors, the corresponding HRs (95% CIs) were 0.67 (0.46-0.96) and 0.92 (0.51-1.68) respectively. Having sauna baths was associated with a reduced risk of VTE in a middle-aged male Caucasian population. Further studies in other populations and age groups are required to confirm these findings.