Social network diversity and risks of ischemic heart disease and total mortality: findings from the Copenhagen City Heart Study

Measures of various types of social contacts were used as predictors of ischemic heart disease events and total mortality in an age-stratified random sample of 9,573 adults enrolled in the Copenhagen City Heart Study (Copenhagen, Denmark). Baseline examinations were conducted in 1991-1994, and participants were followed until the end of 1997. Contacts with parents, children, family members, and friends were associated with better health. The presence of a spouse or partner was protective for men. Contacts with neighbors showed a trend toward a reversed pattern, and the effects of contacts with work colleagues and children differed by gender. Most types of contacts that occurred at least monthly were just as protective as those occurring more frequently. An index of intimate social contact diversity with family and friends had graded relations with both outcomes. Comparisons of persons reporting three or more types of contacts with those reporting fewer types yielded age- and gender-adjusted hazard ratios of 0.73 (95% confidence interval (CI): 0.64, 0.82) for mortality and 0.75 (95% CI: 0.61, 0.91) for ischemic heart disease. Comparable fully adjusted hazard ratios were 0.83 (95% CI: 0.73, 0.95) and 0.82 (95% CI: 0.67, 1.00). These data suggest that health benefits are derived from the diversity of social roles, especially those involving intimate relationships.