How Loneliness Gets Under the Skin: Inflammation Mediates the Relationship Between Loneliness and Gait Speed

Area of Science:

• Psychology
• Biomedical Science
• Public Health

Background:

• Loneliness is associated with interleukin-6 (IL-6), a marker of systemic inflammation.
• Chronic inflammation has detrimental effects on physical and mental health across adulthood.

Purpose of the Study:

• To investigate the cross-sectional relationships among loneliness, IL-6, and slowed gait.
• To examine the mediating role of IL-6 in the association between loneliness and gait speed.

Main Methods:

• Utilized data from the Midlife Development in the United States Biomarker Project (N=822).
• Employed PROCESS macro to test mediation hypotheses, adjusting for demographic and health factors.
• Analyzed relationships between loneliness, IL-6, body mass index (BMI), and gait speed.

Main Results:

• Loneliness, age, sex, BMI, and waist-hip ratio significantly predicted IL-6 levels.
• Serial mediation analyses revealed that loneliness influenced walking time through BMI and IL-6.
• BMI and IL-6 showed specific indirect effects on walking time, indicating multiple pathways.

Conclusions:

• Loneliness may elevate systemic inflammation, contributing to slowed gait and adverse health outcomes.
• Psychosocial interventions targeting loneliness may be effective in reducing inflammation.
• Addressing loneliness could be a key strategy for preventing age-related health declines.