When couples’ hearts beat together: Linkages in heart rate variability during conflict predict heightened inflammation throughout the day

An unhappy marriage increases disease and mortality risks. Discordant couples exhibit stronger links to their partner’s autonomic fluctuations–that is, stronger covariation–than do satisfied couples, but whether this physiological signature plays a role in marriage’s health effects is unknown. To examine associations between couples’ heart rate variability (HRV) covariation during conflict and their inflammation levels, 43 married couples engaged in a marital problem discussion while wearing heart rate monitors and provided blood samples throughout the day. Multilevel models treated log-transformed interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS) stimulated IL-6 and TNF-alpha, intercellular adhesion molecule-1 (ICAM-1), and vascular adhesion molecule-1 (VCAM-1) as outcomes, accounting for morning baseline HRV levels, age, gender, trunk fat, marital satisfaction, hostility observed during the problem discussion, and study design features. Couples whose moment-to-moment HRV changes tracked more closely together during conflict had higher serum IL-6 ( p = 0.04), LPS-stimulated IL-6 ( p = 0.02), VCAM- 1 ( p = 0.01), and at a trend level, LPS-stimulated TNF-alpha ( p = 0.06) across the day. Thought to result in part from couples’ exchange of negative emotion during disagreement, stronger HRV covariation predicted a heightened inflammatory profile beyond the roles of general marital quality and observed negativity. These data highlight partners’ conflict-related HRV linkage as a novel social-biological mechanism explaining marital discord’s connection to inflammation-related disease.