Am J Physiol Heart Circ Physiol. 2026 May 11. doi: 10.1152/ajpheart.00020.2026. Online ahead of print.
ABSTRACT
BACKGROUND. Vascular dysfunction and exercise intolerance contribute to chronic kidney disease (CKD) related cardiovascular disease. Passive heat exposure provides a physiological stimulus for beneficial vascular adaptations and improvements in exercise capacity but has not yet been investigated in CKD. The purpose of this pilot study was to examine the physiological response to acute bout of passive heat exposure in patients with CKD. METHODS. In this randomized, crossover trial, 10 participants with Stage G2-G4 CKD were enrolled (MeanSEM; Age, 414yrs; 6 females; eGFR, 557ml/min/1.73m2). After completing a baseline visit, participants completed two experimental visits: passive heat exposure via far-infrared sauna (HT; 25 min, 60C), and thermoneutral control (CON; 25 min, 22C). Macrovascular function, assessed by flow-mediated dilation (FMD), and microvascular function, assessed by the blood flow response to passive limb movement, were measured after a 60-minute recovery period following exposure on each experimental visit. Exercise capacity was assessed with the 6-minute walk test. Urinary markers of kidney function and injury were collected immediately and over 24 hours following visits. RESULTS. FMD (3.840.61 vs. 6.680.76%, p<0.01) and leg blood flow response to passive limb movement (AUC, 17929 vs. 24323a.u., p=0.01) were greater following HT compared to CON. There was a clinically meaningful difference in 6-minute walk distance between CON (63229yards) and HT (67030yards, p<0.01). There were no significant changes in kidney function or biomarkers of acute kidney injury following HT. CONCLUSION. In this pilot study, A single bout of passive heat exposure acutely improved vascular function and exercise capacity in patients with CKD.
PMID:42113470 | DOI:10.1152/ajpheart.00020.2026