Exercise-induced changes in oxygen saturation in the calf muscles of elderly subjects with peripheral vascular disease

• Published in: Journal of gerontology (Kirkwood) Vol. 49; no. 3; p. B128
• Main Authors: McCully, K K, Halber, C, Posner, J D
• Format: Journal Article
• Language: English
• Published: United States 01-05-1994
• Subjects: Adult; Aged; Ankle - physiology; Arm - physiology; Blood Pressure - physiology; Hemoglobins - metabolism; Humans; Intermittent Claudication - metabolism; Intermittent Claudication - physiopathology; Leg; Middle Aged; Muscles - metabolism; Oxygen Consumption - physiology; Pain - physiopathology; Peripheral Vascular Diseases - metabolism; Peripheral Vascular Diseases - physiopathology; Physical Exertion - physiology; Spectrophotometry, Infrared; Walking - physiology
• ISSN: 0022-1422
• DOI: 10.1093/geronj/49.3.B128

This study noninvasively measured hemoglobin oxygen saturation in young (n = 6, 28 +/- 6 yrs), old healthy (n = 20, 68 +/- 7 yrs), and old subjects with mild peripheral vascular disease (PVD) (n = 8, 72 +/- 4 yrs). Hemoglobin oxygen saturation was measured as the difference in absorption at 760 and 850 nm light using near-infrared spectroscopy (NIRS). The lateral soleus muscle was studied after mild plantar flexion exercise. The time constant of recovery of oxygen saturation (HBO2Tc) was 21.5 +/- 8.6 s in young, 26.9 +/- 13.5 s in old healthy subjects. PVD subjects had HbO2Tc values of 104.4 +/- 41.1 s in their "bad" leg and 57.6 +/- 42.2 s in their "good" leg. The correlation between HbO2Tc and ankle-arm pressures was significant (r2 = .63, p < .001). Six younger normal, five older normal, and seven PVD subjects also performed a progressive walking test. Normal subjects completed the test without difficulty, and older normal subjects showed progressive deoxygenation. PVD subjects complained of calf pain (4 out of 5 were able to finish) and showed near-maximal deoxygenation throughout the test. In summary, NIRS measurements show promise as a method of evaluating the kinetics of oxygen saturation, particularly in patients with mild peripheral vascular disease.