Foot ulcerations are among the most common and debilitating lower extremity complications in individuals with type 2 diabetes (T2D) and peripheral artery disease (PAD). Both conditions are strongly associated with impaired microvascular function and reduced tissue oxygenation in the foot, underscoring the need for therapeutic strategies that can enhance regional perfusion. Objective: To evaluate the feasibility and acute physiological effects of combined lower-leg heat therapy and intermittent pneumatic compression in adults with T2D, PAD, and non-diabetic controls. Hypothesis: The intervention would increase plantar foot oxygenation and leg blood flow in all groups, with attenuated responses in T2D and most prominently in PAD. Methods: Participants included individuals with T2D (n=12, 6 females, 65±7 yr, HbA1c 7.2±1.0%, ankle–brachial index ABI 1.14±0.16), PAD (n=9, 2 females, 69±9 yr, HbA1c 7.0±1.3%, ABI 0.64±0.15), and non-diabetic controls (n=20, 16 females, 63±8 yr, HbA1c 5.7±0.4%, ABI 1.15±0.06). The leg with the lowest ABI was assigned to receive the intervention, while the contralateral leg served as control. Treatment consisted of a boot-like garment containing inner water-circulating pads (40°C) and outer inflatable bladders delivering intermittent pneumatic compression (20 mmHg) for 60 minutes. Near-infrared spectroscopy (NIRS) continuously measured plantar forefoot oxygenation by quantifying oxyHb+Mb and deoxyHb+Mb to compute tissue oxygen saturation (StO 2 ). Popliteal artery blood flow was assessed bilaterally using Doppler ultrasound. Changes from baseline to 60 minutes were analyzed using two-way ANOVA with Tukey post hoc tests. Results: Foot skin temperature increased similarly across groups in the treated leg (~6°C dorsal; ~4°C plantar, p >0.05). Significant group × treatment interactions were observed for StO 2 and oxyHb+Mb (both p0.05 vs. controls). Popliteal blood flow increased in the treated leg in all groups (controls: +23.4±17.1 ml/min; T2D: +63.0±70.7 ml/min; PAD: +32.0±25.6 ml/min; p >0.05), with minimal change in the non-treated leg. Conclusions: Combined heat therapy and intermittent pneumatic compression acutely increased leg perfusion and was well tolerated in individuals with T2D and PAD. However, improvements in plantar foot oxygenation were markedly diminished in PAD despite comparable increases in upstream blood flow, suggesting impaired microvascular responsiveness. These findings support continued investigation of this non-pharmacological intervention as a strategy to improve foot perfusion in individuals at heightened risk for ulceration. Funding: Supported by The John Martinson Honors College’s Research Breakthrough Award from Purdue University. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Miller et al. (Fri,) studied this question.