Coronary risk factors? Sauna therapy may be just the thing

Shelley Wood

October 01, 2001

Kagoshima, Japan - In a finding that would warm the heart of the most stubborn couch potato, Japanese researchers have found that sitting in a sauna once a day might benefit the heart in the same way as regular exercise. In a study examining the effects of thermal vasodilation therapy on vascular function, Dr Masakazu Imamura (Kagoshima University, Japan) and colleagues report that people with one or more CVD risk factors may benefit from repeat sauna therapy over the long term.

"We hypothesized that repeated sauna therapy can improve impaired endothelial function in the setting of conventional coronary risk factors," the authors write in the October 2001 issue of the Journal of the American College of Cardiology.

Imamura and colleagues have previously shown that regular use of a 60C sauna improves vessel function, hemodynamics, and clinical symptoms in people with chronic heart failure, and point out that therapeutic heat exposure generally is widely used in non-Western medicines. For the present study, they looked specifically at whether thermal treatments could improve endothelial function in people with risk factors for coronary disease, but with no existing plaques or stenoses.

Heating up

The researchers' study compared 25 men with one or more risk factors to 10 healthy men with no known CVD risk. For 2 weeks, the "risk group" spent 15 minutes of every day in a far infrared-ray dry sauna system, followed by 30 minutes lying down in a bed covered by blankets. The control group did not undergo treatment.

Endothelial function in both groups was assessed using Doppler ultrasound measurements of vessel diameter and left brachial artery flow velocity. Endothelium-independent vasodilation was assessed the same way after nitroglycerine administration.

Imamura et al report that percent endothelium-dependent flow-mediated dilation was significantly impaired in the risk group, but not in the control group at baseline. After 2 weeks, people who had undergone sauna therapy demonstrated significant improvements in endothelium-dependent vasodilation, but endothelium-independent vasodilation did not change.

The implications, say the authors, are that the thermal treatments have a beneficial effect on impaired endothelium, potentially by enhancing the availability of nitric oxide or decreasing plasma glucose concentration. The endothelial effects appear to be similar to those seen in studies of regular cardiovascular activities, suggesting that thermal therapy might be helpful to people who are unable to exercise.

"Further studies in larger numbers of individuals with conventional coronary risk factors are needed," the authors conclude. They emphasize that their small study was unable to look at the connections between individual risk factors, endothelial dysfunction, and the effects of sauna therapy, and that these would need closer examination.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.