Age-Related Reduction of Systemic Arterial Compliance Induces Excessive Myocardial Oxygen Consumption during Sub-Maximal Exercise

• Published in: Hypertension research Vol. 29; no. 2; pp. 65 - 73
• Main Authors: Otsuki, Takeshi, Maeda, Seiji, Kesen, Yumiko, Yokoyama, Noriko, Tanabe, Takumi, Sugawara, Jun, Miyauchi, Takashi, Kuno, Shinya, Ajisaka, Ryuichi, Matsuda, Mitsuo
• Format: Journal Article
• Language: English
• Published: England 01.02.2006
• Subjects: Age Factors; Aged; Aged, 80 and over; Aging - physiology; Arteries - physiology; Blood Pressure; Compliance; Exercise - physiology; Female; Heart Rate; Humans; Male; Middle Aged; Myocardium - metabolism; Oxygen - metabolism; Oxygen Consumption - physiology
• ISSN: 0916-9636; 1348-4214
• DOI: 10.1291/hypres.29.65

Reduction of systemic arterial compliance (SAC) with aging increases left ventricular afterload. The present study was designed to examine whether age-related reduction of SAC is related to excessive myocardial oxygen consumption during sub-maximal aerobic exercise. We studied elderly (60-69 years; n = 25) and senior (70-82 years; n = 25) subjects. We measured SAC immediately before the start of the ramp-fashion exercise (i.e., at the end of the 20 W warm-up exercise) and the double product (DP: systolic blood pressure x heart rate) during the ramp-fashion exercise (20-50 W). SAC was significantly lower in senior subjects (0.76 +/- 0.25 ml mmHg(-1) m(-2)) compared with elderly subjects (0.95 +/- 0.22 ml mmHg(-1) m(-2)). DP was higher in senior subjects (20 W: 14.3 +/- 3.1; 30 W: 15.9 +/- 4.2; 40 W: 17.7 +/- 4.9; 50 W: 20.6 +/- 5.6 [x 10(3) mmHg bpm]) than in elderly subjects (12.8 +/- 3.0, 14.0 +/- 3.5, 15.1 +/- 4.0, 17.1 +/- 4.3 [x 10(3) mmHg bpm]). In total subjects, SAC correlated significantly with DP (r = -0.64, r = -0.64, r = -0.64, r = -0.64). In senior subjects, SAC was related significantly to DP (r = -0.83, r = -0.78, r = -0.76, r = -0.74). In elderly subjects, SAC tended to correlate with DP although its relationships were not statistically significant (r = -0.34, r = -0.36, r = -0.33, r = -0.31). Correlation coefficients at each respective exercise intensity were significantly higher in senior subjects compared with elderly subjects. These results suggest that the age-related reduction of SAC is related to excessive myocardial oxygen consumption during sub-maximal aerobic exercise in older humans, but this relation does not become significant until the SAC reduction becomes pronounced.