Background: Cardiovascular disease (CVD) burden disproportionately affects African-American adults in the United States. Greater social networks, or social integration, may lower CVD risk among African-American adults. Objective: To determine the association of social networks and incident coronary heart disease (CHD), stroke, and heart failure (HF) and test whether there are differences by sex. Methods: Among participants of the Jackson Heart Study without CVD at baseline (mean age: 54.4 years, n=3,053 women, n=1684 men), we used the Social Networks Index at baseline (2000-2004) to develop a continuous social networks score in standard deviation units (range 0-5) and binary categories (high vs. low relative to the median). Surveillance of CHD, stroke, and HF events occurred after exam 1 (2005 for HF) until 2016. We utilized Cox proportional hazards regression to estimate hazard ratios (HR 95% confidence interval-CI) of each CVD event by levels of social networks, adjusting for demographics, education, behaviors, risk factors and depressive symptoms. Interaction terms by sex were used to evaluate sex differences. Results: There were 262 CHD events, 213 stroke events, and 331 HF events that occurred by 2016. P-values for interaction terms by sex were statistically significant for stroke and HF ( p <0.05). After full adjustment, a 1-SD unit increase in social networks was associated with a lower hazard of CHD and HF among women (HR 0.80, 95% CI 0.72, 0.90 and HR 0.81 95% CI 0.69, 0.98, respectively). Men had a lower hazard of CHD with every 1-SD unit increase in social networks (HR 0.88, 95% CI 0.79, 0.99) after full adjustment. High vs. low social networks was associated with a lower hazard of stroke (HR 0.58, 95% CI 0.35, 0.98) and HF (HR 0.61, 95% CI 0.39, 0.94) among women after full adjustment. Conclusion: Men and women who reported greater social networks were less likely to have a CHD event, but women with greater social networks were less likely to have stroke and HF.

Background: Cardiovascular disease (CVD) disproportionately affects African American adults. Greater social networks (SN), or social connectedness, may lower the risk of CVD events. Objective: Determine the association of SN and incident CVD and test mediation by depressive symptoms, hypertension control and diabetes control. Methods: We used the Social Network Index (SNI) at exam 1 (2000-2004) to develop a continuous standardized SN score and binary categories (high vs. low) among participants in the Jackson Heart Study (n=5252, mean age=54.8 years). Surveillance of coronary heart disease (CHD), stroke, and heart failure (HF) events occurred after exam 1 (2005 for HF) until 2016. Using Cox proportional hazards regression, we estimated the association of SN and CVD events by sex and tested the mediation of depressive symptoms, hypertension control and diabetes control. Models adjusted for age, education, health behaviors, and CVD co-morbidities. Results: Among women, the SN score was associated with a lower risk of CHD and HF after full adjustment (HR 0.78, 95% CI 0.68, 0.89 and HR 0.78, 95% CI 0.63, 0.95, respectively), but the association with stroke attenuated after adjustment for co-morbidities (HR 95% CI 0.88 95% CI 0.67, 1.14). SN scores were also associated with CHD in men (HR 0.84, 95% CI 0.70, 0.99) after full adjustment. High vs. low SN was associated with CHD in men and women, but not after adjustment for co-morbidities. There was no evidence of mediation by depressive symptoms, diabetes control, and hypertension control. Conclusion: Higher SN may lower the risk of CVD events, especially in women.