Heat therapy vs. supervised exercise therapy for peripheral arterial disease: a 12-wk randomized, controlled trial

Abstract

Peripheral arterial disease (PAD) is characterized by lower limb atherosclerosis impairing blood supply and causing walking-induced leg pain or claudication. Adherence to traditional exercise training programs is poor due to these symptoms despite exercise being a mainstay of conservative treatment. Heat therapy improves many cardiovascular health outcomes, so this study tested if this was a viable alternative cardiovascular therapy for PAD patients. Volunteers with PAD were randomized to 12 wk of heat ( n = 11; mean age 76 ± 8 yr, BMI 28.7 ± 3.5 kg/m2, 4 females) or exercise ( n = 11; 74 ± 10 yr, 28.5 ± 6.8 kg/m2, 3 females). Heat involved spa bathing at ∼39°C, 3–5 days/wk for ≤30 min, followed by ≤30 min of callisthenics. Exercise involved ≤90 min of supervised walking and gym-based exercise, 1–2 days/wk. Following the interventions, total walking distance during a 6-min walk test increased (from ∼350 m) by 41 m (95% CI: [13, 69], P = 0.006) regardless of group, and pain-free walking distance increased (from ∼170 m) by 43 m ([22, 63], P < 0.001). Systolic blood pressure was reduced more following heat (−7 mmHg, [−4, −10], P < 0.001) than following exercise (−3 mmHg, [0, −6], P = 0.078), and diastolic and mean arterial pressure decreased by 4 mmHg in both groups ( P = 0.002). There were no significant changes in blood volume, ankle-brachial index, or measures of vascular health. There were no differences in the improvement in functional or blood pressure outcomes between heat and exercise in individuals with PAD. NEW & NOTEWORTHY Heat therapy via hot-water immersion and supervised exercise both improved walking distance and resting blood pressure in peripheral arterial disease (PAD) patients over 12 wk. Adherence to heat therapy was excellent, and the heat intervention was well tolerated. The results of the current study indicate that heat therapy can improve functional ability and has potential as an effective cardiovascular conditioning tool for individuals with PAD. Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/heat-therapy-vs-exercise-in-peripheral-arterial-disease/ .

A systematic review of the role of heat therapy for patients with intermittent claudication due to peripheral artery disease

“…Three studies met the inclusion criteria for intervention analysis. 17,22,23 Akerman et al compared heat therapy to a SEP, Shinsato et al compared heat therapy to usual care (best medical therapy) and Monroe et al compared heat therapy to a sham treatment. None of the heat therapy treatments (including duration, frequency and type) in the studies were the same ( Table 1).…”

“…None of the heat therapy treatments (including duration, frequency and type) in the studies were the same ( Table 1). The heat therapy treatments included whole-body immersion (up to shoulder height) 17 , Waon therapy (dry sauna) 22 and lower-body water-perfused suit. 23 Owing to these differences, we did not pool data for the purpose of a meta-analysis.…”

Could Heat Therapy Be an Effective Treatment for Alzheimer’s and Parkinson’s Diseases? A Narrative Review

“…Heat therapy has recently been targeted as a potential vehicle to evoke these positive thermal-induced adaptations in those precluded from undertaking exercise. Experimental investigations, large cohort surveys and reviews have expressed the potential for passive heating to improve physical and mental health in patients with cardiovascular disease (Brunt et al, 2016a,b;Maeda et al, 2018), diabetes (Kimball et al, 2018;Maley et al, 2019), peripheral arterial disease (Akerman et al, 2019), and depression (Janssen et al, 2016).…”

“…Several vascular adaptations attributable to heat therapy have been reported. These have included improved flow-mediated dilation (Brunt et al, 2016a), increased pulse wave velocity (an index of arterial stiffness) (Brunt et al, 2016a), reduced carotid intima thickness (Brunt et al, 2016a) improved capillarization (Hesketh et al, 2019) and subsequently enhanced systemic blood pressure profiles (Brunt et al, 2016a;Akerman et al, 2019). Mechanistically, HSP27 has been shown to reduce intimal hyperplasia (Connolly et al, 2003), with greater carotid intima thickness associated with reduced cerebral blood flow (Sojkova et al, 2010).…”

“…While in an acute sense this stress response is a defense mechanism, regularly challenging the thermal equilibrium via active or passive thermal stress results in positive physiological and perceptual adaptations (Tyler et al, 2016). Recent research has shown positive therapeutic effects of passive heating for people with peripheral arterial disease (Neff et al, 2016;Akerman et al, 2019), chronic heart failure (Kihara et al, 2002;Ohori et al, 2012), diabetes (Hooper, 1999), and depression (Janssen et al, 2016). Passive heating also improves a range of health markers, including cardiovascular health indices, such as vascular function, blood pressure, and arterial stiffness (Brunt et al, 2016a,b), as well as metabolic health and glycemic control (Janssen et al, 2016;Kimball et al, 2018;Ely et al, 2019;Maley et al, 2019).…”