title: Renal vasoconstriction is augmented during exercise in patients with peripheral arterial disease.
abstract: Peripheral arterial disease (PAD) patients have augmented blood pressure increases during exercise, heightening their cardiovascular risk. However, it is unknown whether patients have exaggerated renal vasoconstriction during exercise and if oxidative stress contributes to this response. Eleven PAD patients and 10 controls (CON) performed 4-min mild, rhythmic, plantar flexion exercise of increasing intensity (0.5-2 kg) with each leg (most and least affected in PAD). Eight patients also exercised with their most affected leg during ascorbic acid (AA) infusion. Renal blood flow velocity (RBFV; Doppler ultrasound), mean arterial blood pressure (MAP; Finometer), and heart rate (HR; electrocardiogram [ECG]) were measured. Renal vascular resistance (RVR), an index of renal vasoconstriction, was calculated as MAP/RBFV. Baseline RVR and MAP were similar while HR was higher in PAD than CON (2.08 ± 0.23 vs. 1.87 ± 0.20 au, 94 ± 3 vs. 93 ± 3 mmHg, and 72 ± 3 vs. 59 ± 3 bpm [P < 0.05] for PAD and CON, respectively). PAD had greater RVR increases during exercise than CON, specifically during the first minute (PAD most: 26 ± 5% and PAD least: 17 ± 5% vs. CON: 3 ± 3%; P < 0.05). AA did not alter baseline RVR, MAP, or HR. AA attenuated the augmented RVR increase in PAD during the first minute of exercise (PAD most: 33 ± 4% vs. PAD most with AA: 21 ± 4%; P < 0.05). In conclusion, these findings suggest that PAD patients have augmented renal vasoconstriction during exercise, with oxidative stress contributing to this response.
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Drew
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Muller
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Blaha
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Mast
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Heffernan
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Estep
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Jian
authors.initials: J
authors.lastname: Cui
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Amy B
authors.initials: AB
authors.lastname: Reed
authors.affiliation: Penn State Hershey Heart and Vascular Institute, Penn State University College of Medicine Hershey, Pennsylvania.
authors.forename: Lawrence I
authors.initials: LI
authors.lastname: Sinoway
keywords: Exercise; oxidative stress; peripheral arterial disease; renal