Postexercise Ischemia Is Associated With Increased Neuropeptide Y in Patients With Coronary Artery Disease

Abstract

Background-Neurohormones may influence vascular tone both during and after exercise. Neuropeptide Y (NPY), which is costored and released with norepinephrine (NE) during sympathetic activity, is a potent vasoconstrictor with a relatively long half-life. We therefore examined its possible association with the ischemic response to exercise in patients with coronary artery disease. Methods and Results-Twenty-nine male patients with effort-induced angina pectoris underwent a symptom-limited exercise test. In addition to conventional ST-segment analysis, we examined ischemia on the basis of heart rate (HR)-adjusted ST-segment changes through calculation of the ST/HR slope during the final 4 minutes of exercise and of the ST/HR recovery loop after exercise. Blood samples were taken before, during, and after exercise for an analysis of several neurohormones. Mean ST-segment depression was Ϫ223Ϯ20.2 V (PϽ0.0001) just before the termination of exercise, followed by a gradual normalization, but it remained significant after 10 minutes (Ϫ49Ϯ8.9 V, PϽ0.0001). At the end of exercise, the ST/HR slope, which reflects myocardial ischemia, was Ϫ6.0Ϯ0.77 V/HR. In most patients, ST-segment levels at a given HR were lower during recovery than during exercise, here referred to as ST "deficit." Exercise increased the plasma levels of NPY, NE, epinephrine, and N-terminal proatrial natriuretic peptide, but big endothelin remained unchanged. Although NE and epinephrine peaked at maximal exercise, the highest levels of NPY and N-terminal proatrial natriuretic peptide were observed 4 minutes after exercise. The maximal increase in the NPY correlated significantly with ST-segment depression at 3 minutes after exercise (rϭϪ0.61, Pϭ0.0005), the ST deficit at the corresponding time point (rϭϪ0.66, Pϭ0.0001), and the duration of ST-segment depression after exercise (rϭ0.42, Pϭ0.02). In contrast, no such correlations were found for NE. Conclusions-The present study has for the first time demonstrated a correlation between plasma NPY levels and the degree and duration of ST-segment depression after exercise in patients with coronary artery disease, which suggests that NPY may contribute to myocardial ischemia in these patients. (Circulation. 2000;102:987-993.)

The influence of physical exercise on alterations in concentrations of neuropeptide Y, leptin and other selected hormonal and metabolic parameters in sportspeople

“…Other authors' results suggest, [8,18,24], increase of NPY concentration during physical exercise. In our studies we also obtained significant rise of NPY in group I and II, observing a drop of concentration of this peptide in restitution in cyclists only.…”

“…NPY presents in the serum originates mainly from sympathetic nerve endings of blood vessels and of the heart that release it into synaptic clefts from which it penetrates into the bloodstream. NPY was shown to be released into the bloodstream in food deficiency after intense physical exercise enhancing vasoconstrictive action of noradrenaline [4,8,13,18,19,24,38].…”

Exercise Electrocardiogram Testing

“…23,[87][88][89][90] Data can be examined qualitatively as the simple rate-recovery loop, 91 with findings from the first minute of recovery, when patients with ischemia generally have greater ST-segment depression than was present at the corresponding heart rate during exercise before peak effort ( Figure 2). In contrast to standard ST-depression criteria and heart rate-adjusted criteria derived purely from exercise phase data, the sensitivity of the rate-recovery loop appears to be relatively independent of the extent of disease.…”

“…A relatively simple quantification of the raterecovery loop involves calculation of the ST-segment "deficit" between recovery phase ST depression at 3.5 minutes and the ST depression at the corresponding heart rate during exercise. 89,93 ST/HR hysteresis, as developed by Lehtinen et al, 88,94,95 integrates the area of ST-segment depression with respect to heart rate that is included in the exercise and recovery loop over the heart rate range included in the first 3 minutes of recovery. This integral is then divided by the heart rate difference (ie, the maximum heart rate during exercise minus the minimum heart rate during recovery) of the integration interval to normalize the result with respect to the postexercise heart rate decline.…”

Electrocardiographic exercise stress testing: An update beyond the ST segment

“…Changes in recovery are just as significant for predicting risk for cardiac events (angina, MI, cardiac death) as those that occur during exercise [84]. In addition to supply-demand induced ischemia, levels of neuropeptide Y, a potent vasoconstrictor released with norepinephrine during sympathetic activity, has been shown to correlate with the degree and duration of ST-segment depression after exercise in patients with CAD [85].…”