Sauna for peripheral arterial disease of the lower extremities
Evidence review
Overview
Waon therapy (140 F far-infrared sauna) was tested in a small randomized trial of patients with peripheral arterial disease, in which leg pain, ankle-brachial index and 6-minute walk distance improved within the Waon group but not in controls after 6 weeks; the groups were not compared directly, and a review found the between-group differences not significant. In a 12-week RCT, hot-water spa bathing at about 102 F and supervised exercise produced similar gains in walking distance and resting blood pressure, without change in ankle-brachial index; the trial was small and had no untreated control. A single 30-minute waist-level hot-water immersion markedly increased leg blood flow and lowered blood pressure in PAD patients. A 2021 systematic review found that walking distance and ABI improved with whole-body hot-water immersion but not significantly with Waon therapy.
Key findings
- RCT (n=21, 6 weeks daily Waon): leg pain, ABPI and 6MWD improved significantly in the Waon group but not in controls; circulating CD34+ cells rose from 2.0 to 3.9 (x10^-4), p=0.015.
- RCT (n=22, 12 weeks): 6MWD +41 m (95% CI 13-69) and pain-free walking +43 m (22-63) with either spa bathing or supervised exercise; systolic BP -7 mmHg after heat vs -3 mmHg after exercise; no change in ABI.
- Single 30-min immersion at 107.8 F in PAD (n=11): popliteal shear rate +258%, leg blood flow more than doubled; mean arterial pressure 7 mmHg lower 3 h later.
- Systematic review (3 RCTs, 73 participants): 6MWD improved after whole-body hot-water immersion vs exercise (ES 0.94, 95% CI 0.06-1.82) but not after Waon therapy vs medical care (ES 0.77, 95% CI -0.12 to 1.66); one heating-related adverse event (skin irritation).
- No heat therapy improved quality of life or brachial BP in the review.
Every study we reviewed
2 mixed results · 3 found benefit
Each study was checked on PubMed. The colored edge shows the direction of the result. The research library lists 18 studies on peripheral artery and circulatory disease, across all heat and cold therapies, including case reports and older work not graded here.
A systematic review of the role of heat therapy for patients with intermittent claudication due to peripheral artery disease.
Harwood AE et al. Vasc Med. 2021. PubMed 33587690 · DOI · Free full text
- Who
- Patients with intermittent claudication (Fontaine IIA/IIB, mean age 73, 76% men): 3 RCTs with 73 participants (37 given heat therapy) and 3 acute studies
- What
- Heat therapy: whole-body hot-water immersion, Waon therapy, water-perfused garment
- Measured
- 6MWD, ABPI, QoL, BP
- Result
- No meta-analysis. Between-group effect sizes computed by the review: 6MWD improved after whole-body immersion vs supervised exercise (p=0.03; ES 0.94, 95% CI 0.06-1.82) but not after Waon therapy vs medical care (ES 0.77, 95% CI -0.12 to 1.66) or a water-perfused garment vs sham (ES 0.16, 95% CI -0.56 to 0.87); ABPI improved only after immersion (ES 1.10, 95% CI 0.20-1.99; Waon ES 0.50, 95% CI -0.37 to 1.37); no improvement in QoL or brachial BP. Only one heating-related adverse event (skin irritation) across trials.
- Limitations
- Only 3 small RCTs, each with a different modality; no pooling; the immersion group also did calisthenics; trials lasted 6-12 weeks with no longer follow-up.
Waon therapy mobilizes CD34+ cells and improves peripheral arterial disease.
Shinsato T et al. J Cardiol. 2010. PubMed 20843662 · DOI · Free full text
- Who
- Patients with PAD on standard medications (Japan)
- What
- Daily Waon therapy (n=11) vs conventional therapy (n=10), 6 weeks
- Protocol
- 140 °F · 15 min · daily/wk · 6 wk
- Measured
- Leg pain VAS, ankle-brachial pressure index, 6MWD, CD34+ cells
- Result
- Leg pain, ABPI and 6MWD improved significantly only in the Waon group (values not given in abstract); CD34+ cells 2.0 to 3.9 x10^-4 (p=0.015) vs 1.8 to 1.2 in controls; serum nitrate/nitrite 29.6 to 36.0 (p<0.05).
- Limitations
- Very small; open-label; within-group comparisons; effect sizes for clinical outcomes not reported in abstract.
Heat therapy vs. supervised exercise therapy for peripheral arterial disease: a 12-wk randomized, controlled trial.
Akerman AP et al. Am J Physiol Heart Circ Physiol. 2019. PubMed 31002283 · DOI · Free full text
- Who
- Patients with peripheral arterial disease and claudication, mean age about 75 (New Zealand)
- What
- Hot-water spa bathing at about 102 F for up to 30 min, 3-5 days/week, followed by up to 30 min of calisthenics (n=11) vs supervised walking and gym exercise up to 90 min, 1-2 days/week (n=11)
- Protocol
- 102 °F · <=30 min · 3-5/wk · 12 wk
- Measured
- 6-minute walk distance, pain-free walking distance, BP, ABI, vascular function
- Result
- 6MWD rose by 41 m (95% CI 13-69) and pain-free walking distance by 43 m (22-63) regardless of group; SBP fell 7 mmHg after heat (95% CI -4 to -10) and 3 mmHg after exercise (0 to -6); DBP and MAP fell 4 mmHg in both. No change in ABI, blood volume or vascular measures; no between-group differences.
- Limitations
- Small; no untreated control; heat arm included calisthenics; not powered to show equivalence with exercise.
[Experiences with the application of physiotherapy in peripheral arterial circulatory disorders of the lower extremities (stage I and IIa) under ambulatory conditions].
Winterfeld HJ et al. Z Gesamte Inn Med. 1983. PubMed 6603074
- Who
- Outpatients with lower-limb peripheral arterial disease, Fontaine stage I-IIa (East Germany)
- What
- 10-12 weeks of interval walking plus gymnastics (twice weekly), sauna twice weekly, or diadynamic current therapy
- Protocol
- 2/wk · 10-12
- Measured
- Pain-free walking distance, peripheral microcirculation (xenon-133 muscle clearance), BP
- Result
- Peripheral hemodynamics improved in all therapy groups; claudication distance lengthened particularly with interval walking; systolic BP fell significantly in the walking and sauna groups; no side effects.
- Limitations
- Sample size and numeric results not given in abstract; German-language report; walking-distance gain mainly with exercise.
Lower-limb hot-water immersion acutely induces beneficial hemodynamic and cardiovascular responses in peripheral arterial disease and healthy, elderly controls.
Thomas KN et al. Am J Physiol Regul Integr Comp Physiol. 2017. PubMed 28003211 · DOI · Free full text
- Who
- Patients with PAD (n=11, mean age 71) and healthy elderly controls (n=10) (New Zealand)
- What
- Single 30-min waist-level hot-water immersion at 107.8 F
- Protocol
- 107.8 °F · 30 min · single session/wk
- Measured
- Popliteal and brachial blood flow and shear rate, limb perfusion, pulse wave velocity, BP
- Result
- Popliteal shear rate rose 258% in PAD; lower-limb blood flow rose more than 200% (duplex); pulse wave velocity fell; mean arterial pressure fell 22 mmHg during immersion and remained 7 mmHg lower 3 h later.
- Limitations
- Acute single exposure; surrogate hemodynamic outcomes; small.
Protocols used in the studies
Waon RCT: 140 F (60 C) far-infrared sauna for 15 min followed by 30 min blanket rest, daily for 6 weeks, added to standard medication. Spa RCT: hot-water immersion at about 102 F (39 C) for up to 30 min, 3-5 days/week for 12 weeks, followed by calisthenics. Acute study: 30-min waist-level immersion at 107.8 F (42.1 C). An older German study used sauna twice weekly for 10-12 weeks.
What is still unknown
Adequately powered, controlled RCTs of sauna or hot-water immersion in claudication or chronic limb-threatening ischemia; formal comparison with supervised exercise; long-term limb outcomes; whether high-temperature Finnish sauna has similar effects; safety in patients with neuropathy or foot ulcers.
Safety
Cautions for sauna in this condition
- Patients with PAD often have diabetes and reduced foot sensation; a second-degree burn occurred during sauna use in a patient with advanced diabetic neuropathy in a dialysis pilot (PMID 36203760).
- Sauna produces acute BP falls (PMID 29269746), relevant for patients with coexisting coronary disease.
- Waist-level hot-water immersion lowered mean arterial pressure by 22 mmHg during immersion in older PAD patients (PMID 28003211); risk of light-headedness on standing.
- Across the three heat-therapy RCTs in claudication only one heating-related adverse event (skin irritation) was reported, but safety was not systematically assessed (PMID 33587690).
For clinicians
Suggested rationale
A small randomized trial reported that 6 weeks of daily 140 F Waon therapy improved leg pain, ankle-brachial index and walking distance within the treated group in PAD (Shinsato 2010), though between-group differences were not significant in a systematic review's reanalysis (Harwood 2021), and in a small 12-week RCT walking distance improved with hot-water spa bathing at least as much as with supervised exercise (Akerman 2019); heat may be considered only as an adjunct to supervised exercise and medical therapy.
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Typical ICD-10 codes: I73.9, I70.213. Examples only; the clinician assigns the code.
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