Higher Risk of Incident CVD in Older Women Linked to Social Isolation, Loneliness

John Bellettiere, PhD

Social isolation and loneliness were independently associated with a higher risk of incident cardiovascular disease (CVD) in a recent study of older women in the United States, suggesting the need for increased prevention in this cohort.

The study data show an 11.0% - 16.0% higher risk of CVD among postmenopausal women, while higher levels of social isolation and loneliness were associated with a 13.0% - 27.0% higher risk of CVD

Led by study authors Natalie M. Golaszewski, PhD and John Bellettiere, PhD, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, the study hypothesized fewer associations with risk of CVD would be found among women with greater social support.

The prospective cohort study was conducted from March 2011 - March 2019 and included women (65 - 69 years old) from the Women’s Health Initiative Extension Study with no history of myocardial infarction, stroke, or coronary heart disease.

To obtain this population, investigators found two sets of data:

• 61,161 women (75.1%) with complete data on both loneliness and social support.
• 3336 women (5.5%) with a history of myocardial infarction, stroke, and/or CHD.

After exclusion of the latter group, 57,825 (94.5%) women were left for follow-up until the end of the study period of the first reported major CVD event.

Main outcomes were considered major CVD and the first reported occurrence of the event was physician adjudicated using medical records. Both social isolation and loneliness were evaluated utilizing validated questionnaires, including the UCLA Loneliness scale, while social support was assessed using 9 items from the 19-item Medical Outcomes Study Social Support Survey.

Additionally, hazard ratios (HRs) and 95% CIs for CVD were calculated for women with high social isolation and loneliness scores, compared lower scores using multivariable Cox proportional hazards regression models.

In the total cohort (n = 57,825), the mean age was 79.0 years and 89.1% identified as non-HIspanic White. A higher percentage of participants with above-median social isolation and loneliness had depression and diabetes and more likely report poorer self-rated health and less social support.

A total of 1599 major CVD events occurred over 186,762 person-years. Rates of CVD events among women with above-median loneliness was 11.5 per 1000 person-years and 7.4 per 1000 person-years among women with below-median loneliness.

Investigators observed the HR for the association of high versus low social isolation scores with incident CVD was 1.18 (95% CI, 1.13 - 1.23; 18.0% higher risk) and the HR for the association of high versus low loneliness scores with CVD was 1.14 (95% CI, 1.10 - 1.18).

Following additional adjustment for health behaviors and health status, the HR was 1.08 (95% CI, 1.03 - 1.12; 8.0% higher risk) for social isolation and 1.05 (95% CI, 1.01 - 1.09; 5.0% higher risk) for loneliness.

Then, the HRs for the association of both high social isolation scores and high loneliness scores versus both low social isolation scores and low loneliness scores were 1.27 (95% CI, 1.21 - 1.36; 27.0% higher risk) and 1.13 (95% CI, 1.06 - 1.20; 13.0% higher risk), after adjustment.

Lastly, social support was not found to be a significant effect modifier of the associations (social isolation x social support: r, -0.18; P = .86; loneliness x social support: r, 0.78; P = .48).

“The mechanisms through which social isolation and loneliness are associated with incident CVD may partially involve health behaviors and changing health status, although in this study, the results suggest that the associations were not fully explained by these factors,” investigators concluded.

The study, “Evaluation of Social Isolation, Loneliness, and Cardiovascular Disease Among Older Women in the US,” was published in JAMA Network Open.