Social Disadvantage and Social Isolation Are Associated With a Higher Resting Heart Rate: Evidence From The Irish Longitudinal Study on Ageing

OBJECTIVES: A high resting heart rate (RHR) represents a major risk factor for cardiovascular disease and individuals from poorer backgrounds have a higher RHR compared with their more advantaged peers. This study investigates the pathways through which low socioeconomic status (SES) contributes to a higher RHR. METHOD: The sample involved data for 4,888 respondents who were participating in the first wave of The Irish Longitudinal Study on Ageing. Respondents completed a detailed interview at home and underwent a 5-min baseline electrocardiograph recording as part of a clinic-based health assessment. SES was indexed using household income. RESULTS: The mean difference in RHR between those at polarized ends of the income distribution was 2.80 beats per minute (bpm) (95% CI = 1.54, 4.06; p < .001), with the magnitude of the socioeconomic differential being greater for men (4.15 bpm; 95% CI = 2.18, 6.12; p < .001) compared with women (1.57 bpm; 95% CI = 0.04, 3.10; p < .05). Psychosocial factors including social network size and loneliness accounted for a sizeable proportion of the socioeconomic differential in RHR, particularly among men. DISCUSSION: The finding that poorer people have a higher RHR reinforces the need for additional research exploring the pathways through which social inequalities are translated into biological inequalities.