Real-life stress is associated with sympathetic activation in healthy subjects

Abstract

Psychosocial state is a widely studied prognosis factor of coronary heart disease (CHD) and sympathetic activity is linked to adverse events in chronic heart failure or unstable CHD. The aim of this work was to study associations between a real-life stress and a sympathetic activation in healthy subjects evaluated by the pupillary light reflex, blood pressure, heart rate and body temperature. Eighty-five healthy students aged between 18 and 26 participated in the study during an exam week. All subjects were screened to exclude a generalized anxiety disorder or other psychiatric disorders. Psychological state was assessed by the psychic anxiety part of the Hamilton Anxiety scale (HAM-A), with a score of 0 to 24. Assessment of heart rate, blood pressure (mmHg), body temperature (°C) was done after five minutes of sitting, in a quiet and dark room at a constant temperature. Pupillary assessment was performed with a videopupillometer. Pupillary diameters (mm) before and after stimulation were recorded, as well as the pupillary constriction velocity (mm/s) and the latency of the reflex (ms). Median age was 23 (53%, women). The median HAM-A score was 8. In univariate analysis, body temperature ( r = 0.23, P = 0.029) and post-stimulation pupillary diameter ( r = 0.22, P = 0.047) were associated to HAM-A. No correlation was observed between HAM-A and blood pressure, heart rate, pupillary diameter before stimulation or pupillary light reflex latency. In a multivariate analysis by logistic regression, we found a significant association between HAM-A and sex (men) [OR: 0.39; 95% CI (0.15–0.98), P = 0.046], post-stimulation pupillary diameter [OR: 1.69; 95% CI (1.07–2.67); P = 0.024], and body temperature [OR: 3.24; 95% CI (1.07–9.76), P = 0.037]. Real-life stress has an impact on sympathetic activity, shown by post-stimulation pupillary diameter and body temperature. The pupillary light reflex measurement might improve the prediction of CHD events.