Do friends get under the skin?: Everyday social encounters and cardiovascular functioning among Black and White adults in the United States.

Objective: Studies have shown that contact with friends enhances emotional health, but little is known about whether friends influence cardiovascular health. This study investigated (a) whether encounters with friends and the quality of these encounters were associated with cardiovascular reactivity in everyday life and (b) whether these associations varied by race.

Method: Participants were from the Stress and Well-being in Everyday Life Study which included Black (n = 76; aged = 34-76) and White (n = 87, aged = 34-91) adults residing in the United States. Participants provided background and social network information in a baseline interview, followed by a 4-day ecological momentary assessment in which they reported social encounters every 3 hr. Concurrently, participants wore an electrocardiogram monitor which collected physiological data in real time. To assess cardiovascular reactivity, heart rate variability (HRV) was analyzed.

Results: Multilevel models revealed that at times when individuals encountered friends (particularly positive encounters), they exhibited a momentary reduction in HRV (within-person association). But those with more friend encounters during the study period (particularly positive encounters) had higher HRV than those with fewer friend encounters during the study period (between-person association). These links were observed only among Black adults, but not among White adults.

Conclusions: This study contributes to the conceptual model of social integration and enriches the literature on racial disparities in cardiovascular health from a social perspective. Findings highlight the implications of engagement with friends for momentary cardiovascular reactivity and suggest that friends may be more salient for Black adults' cardiovascular health. (PsycInfo Database Record (c) 2024 APA, all rights reserved).