Individual Differences in Cross-System Physiological Activity at Rest and in Response to Acute Social Stress.

Abstract

Individual differences in long-term cardiovascular disease risk are related to physiological responses to psychological stress. However, little is known about specific physiological response profiles in young adults that may set the stage for long-term increased cardiovascular disease risk. We investigated individual differences in profiles of resting cardiovascular physiology and stress reactivity, combining parasympathetic, sympathetic, and hemodynamic measures. Participants (n = 744, 71% women, mean [standard deviation] age = 20.1 [2.4] years) underwent the Trier Social Stress Test, while blood pressure (systolic blood pressure, diastolic blood pressure), electrocardiograms (interbeat interval), and impedance cardiograms (preejection period, left ventricular ejection time) were recorded. Respiratory sinus arrhythmia was derived from the combination of the electrocardiogram and the impedance cardiogram. A three-step latent profile analysis (LPA) was performed on resting and reactivity values to derive clusters of individual physiological profiles. We also explored demographic and health behavioral correlates of the observed latent clusters. For resting physiology, LPA revealed five different resting physiology profiles, which were related to sex, usual physical activity levels, and body mass index. Five cardiovascular stress reactivity profiles were identified: a reciprocal/moderate stress response (Cr1; 29%), and clusters characterized by high blood pressure reactivity (Cr2: 22%), high vagal withdrawal (Cr3; 22%), autonomic coactivation (parasympathetic nervous system and sympathetic nervous system; Cr4; 13%), and overall high reactivity (Cr5; 12%). Men were more likely to belong to the high reactivity (Cr5) cluster, whereas women were more likely to have autonomic coactivation (Cr4). We identified five cardiovascular physiological reactivity profiles, with individuals displaying generalized hyperreactivity, predominant vagal withdrawal, autonomic coactivation, or blood pressure-specific hyperreactivity. Longitudinal studies are needed to determine whether these profiles are useful in early detection of individuals at high risk for cardiovascular disease.