The Association between Social Network Betweenness and Coronary Calcium: A Baseline Study of Patients with a High Risk of Cardiovascular Disease

Abstract

Aim: The association of social networks with cardiovascular disease (CVD) has been demonstrated through various studies. This study aimed to examine the association between social network betweenness -a network position of mediating between diverse social groups-and coronary artery calcium.

Methods: The data of 1,384 participants from the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk Cohort, a prospective cohort study enrolling patients with a high risk of developing CVD (clinicaltrials.gov: NCT02003781), were analyzed. The deficiency in social network betweenness was measured in two ways: only-family networks, in which a respondent had networks with only family members, and no-cutpoint networks, in which the respondent does not function as a point of bridging between two or more social groups that are not directly connected.

Results: Participants who had higher coronary artery calcium scores (CACSs) were likely to have a smaller network size (p＜0.001), only-family networks (p＜0.001), and no-cutpoint networks (p＜0.001). Multiple logistic regression analyses revealed no significant association between network size and CACS. Only no-cutpoint networks had a significant relationship with CACS ＞400 (odds ratio, 1.72; 95% confidence interval, 1.07-2.77; p=0.026). The association was stronger among older (age ＞60 years) and female respondents.

Conclusion: Deficiency in social network betweenness is closely related to coronary calcium in participants with a high risk of CVD. To generalize these results to a general population, further study should be performed.

Keywords: Cardiovascular disease; Coronary calcium score; Risk factor; Social networks.

Fig. 1.

Two possible social networks. Circles represent participants, squares represent social network members from a family (e.g., parent, child, relative), diamonds represent non-family network members (e.g., friend, neighbor), and lines show the social connections. Network size was defined as the total number of social network members. Only-family networks (OF) do not include any non-family member. Compared to A's networks, B's networks are limited in the family. A cutpoint is a person whose deletion breaks up the remaining group into two or more disconnected pieces. If a respondent did not function as a cutpoint of his or her networks, he or she was considered to have no-cutpoint (NC) networks. A's networks show an example of NC networks: A's network members are all connected to at least one other network member even when respondent A is missing, whereas B's networks are divided into the two groups of [b1, b5] and [b2, b3, b4] when respondent B is deleted.

Fig. 2.

ORs and 95% CIs for only-family networks and nocutpoint network from multiple logistic regression analyses of coronary calcium score > 400 in total participants and subgroups. We predicted ORs for only-family networks or no-cutpoint networks after controlling for age, sex, smoking, hypertension, diabetes, ESRD, exercise, depression, statin use, BMI, SBP, LDL-cholesterol, glucose, eGFR, education, income, working, marriage, number of co-habitants, and network size.