title: Diffuse optical characterization of an exercising patient group with peripheral artery disease.
abstract: Peripheral artery disease (PAD) is a common condition with high morbidity. While measurement of tissue oxygen saturation (S(t)O(2)) has been demonstrated, this is the first study to assess both S(t)O(2) and relative blood flow (rBF) in the extremities of PAD patients. Diffuse optics is employed to measure hemodynamic response to treadmill and pedal exercises in 31 healthy controls and 26 patients. For S(t)O(2), mild and moderate/severe PAD groups show pronounced differences compared with controls. Pre-exercise mean S(t)O(2) is lower in PAD groups by 9.3% to 10.6% compared with means of 63.5% to 66.2% in controls. For pedal, relative rate of return of S(t)O(2) to baseline is more rapid in controls (p < 0.05). Patterns of rBF also differ among groups. After both exercises, rBF tend to occur at depressed levels among severe PAD patients compared with healthy (p < 0.05); post-treadmill, rBF tend to occur at elevated levels among healthy compared with severe PAD patients (p < 0.05). Additionally, relative rate of return to baseline S(t)O(2) is more rapid among subjects with reduced levels of depression in rBF (p = 0.041), even after adjustment for ankle brachial index. This suggests a physiologic connection between rBF and oxygenation that can be measured using diffuse optics, and potentially employed as an evaluative tool in further studies.
authors.affiliation: University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, PA 19104, USA. rickson@ifi.unicamp.br
authors.forename: Rickson C
authors.initials: RC
authors.lastname: Mesquita
authors.forename: Mary
authors.initials: M
authors.lastname: Putt
authors.forename: Malavika
authors.initials: M
authors.lastname: Chandra
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yu
authors.forename: Xiaoman
authors.initials: X
authors.lastname: Xing
authors.forename: Sung Wan
authors.initials: SW
authors.lastname: Han
authors.forename: Gwen
authors.initials: G
authors.lastname: Lech
authors.forename: Yu
authors.initials: Y
authors.lastname: Shang
authors.forename: Turgut
authors.initials: T
authors.lastname: Durduran
authors.forename: Chao
authors.initials: C
authors.lastname: Zhou
authors.forename: Arjun G
authors.initials: AG
authors.lastname: Yodh
authors.forename: Emile R
authors.initials: ER
authors.lastname: Mohler
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D016022:Case-Control Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D016491:Peripheral Vascular Diseases / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000502:physiology; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods; D018709:Statistics, Nonparametric
chemical_list: D010100:Oxygen