Social isolation linked to biological age gap, higher mortality rate

A new study from Mayo Clinic finds that socially isolated people are more likely to show signs of being biologically older than their age and more likely to die from a variety of causes. The research, published in the Journal of the American College of Cardiology: Advances, suggests that social connection plays an important role in overall physical health and longevity, and it should be addressed as a necessary part of the social determinants of health.

To investigate the role of social contact in biological aging, the researchers compared the Social Network Index and AI-enabled electrocardiogram (AI-ECG)-predicted age gaps of over 280,000 adults who received outpatient care between June 2019 and March 2022. Eligible participants completed a questionnaire on the social determinants of health and had AI-ECG records independent of the study on file within one year.

An AI-ECG model developed at Mayo Clinic was used to estimate biological age, which was then compared to chronological age. Previous research shows that the AI-ECG age prediction represents the heart's biological age. A positive age gap indicates accelerated biological aging, while a negative value suggests slower biological aging.

Researchers assessed social isolation using the Social Network Index, which asks six distinct multiple-choice questions related to these areas of social interaction:

• Belonging to any social club or organization.
• Frequency of participating in social activities per year.
• Frequency of talking on the telephone with family and friends per week.
• Frequency of attending church or religious services per year.
• Frequency of getting together with friends or family in person per week.
• Marital status or living with a partner.

Each question response was given a score of 0 or 1, and the total score tallies ranged from 0 to 4, representing varying degrees of social isolation.

Participants with a higher Social Network Index score—indicating a better social network—had a smaller AI-ECG age gap, and that held true across all gender and age groups. Social network status significantly influenced mortality risk. During the two-year follow-up period, approximately 5% of the participants died. Those who had low social index scores less than or equal to 1 had the highest risk of death compared to other groups.

While the participants were 86.3% non-Hispanic white, the study data point to existing health disparities. Non-white participants had higher average age gaps than their white counterparts, especially those with lower Social Network Index scores.

"This study highlights the critical interplay between social isolation, health and aging," says Amir Lerman, M.D., a cardiologist at Mayo Clinic and senior author of the paper. "Social isolation combined with demographic and medical conditions appears to be a significant risk factor for accelerated aging. But we also know that people can change their behavior—have more social interaction, exercise regularly, eat a healthy diet, stop smoking, get adequate sleep, etc. Making and sustaining these changes may go a long way toward improving overall health."