Behaviorally elicited heart rate reactivity and atherosclerosis in female cynomolgus monkeys (Macaca fascicularis).

We previously reported that the coronary atherosclerosis of cholesterol-fed, male cynomolgus monkeys (Macaca fascicularis) was exacerbated among animals that exhibited the largest heart rate (HR) reactions to a standard laboratory stressor. Here we report a similar relationship between behaviorally induced HR reactivity and atherosclerosis in females of the same species. Twenty-one female monkeys were fed a moderately atherogenic diet for 30 months. Near the end of this period, animals were fitted with electrocardiogram telemetry devices and their HRs were recorded under baseline and stressed conditions. Stress period HR measurements were obtained during a standard challenge involving threatened capture and physical handling of the animals. At necropsy, sections taken from the left anterior descending, left circumflex, and right coronary arteries were examined histologically. Mean intimal area measurements were then compared between animals identified as High (n = 7) and Low (n = 7) HR reactors. High HR reactive animals were found to have significantly greater coronary artery atherosclerosis than Low reactors; atherosclerosis at the right carotid bifurcation also differed significantly between High and Low reactive monkeys. Groups did not differ in baseline HR, blood pressure, and total or HDL cholesterol concentrations. Relative to Low HR reactors, however, High reactive animals weighed less and were less ponderous, had greater heart weights (adjusted for differences in body weight), were behaviorally less aggressive, and had lower luteal phase progesterone concentrations. These relationships were corroborated in correlation analyses employing data of all 21 study animals.