Blunt Circulatory Response to Exercise in Coronary High-Risk Subjects Among Apparently Healthy Japanese

Background Endothelial dysfunction leads to atherosclerosis and the hypothesis of the present study was that the systemic circulatory response during exercise would be a manifestation of endothelial dysfunction. Methods and Results The circulatory response to exercise of 1,214 apparently healthy people (946 men, mean age 51.2±10.3; 268 women, mean age 52.7±10.1) was investigated, as well as the number of coronary risk factors. Systemic vascular resistance (SVR) was calculated from heart rate, blood pressure and oxygen uptake at rest and at maximal exercise during a ramp protocol using a bicycle ergometer. SVRs at rest (1,751-2,001 (dynes · s · cm-5) in women and 1,528-1,564 in men) did not significantly differ among the groups by number of coronary risk factors. At maximal exercise, however, they were lower in the group with fewer risk factors; that is, among women 929 (dynes · s · cm -5) with no risk factor to 1,305 with 5 risk factors; among men 793 with 1 risk factor to 1,170 with 6 risk factors. Conclusions Those with more coronary risk factors showed a lower but lengthier reduction in SVR during exercise. This weak circulatory response to exercise is a manifestation of deteriorated circulatory function in coronary high-risk subjects. (Circ J 2004; 68: 286 - 293)