Association between loneliness and grip strength in the aging population: insights from Ardakan Cohort Study

Loneliness, a psychosocial condition linked to physical health outcomes in aging populations, is under-researched in relation to objective physical measures like grip strength. This study investigated the association between loneliness and hand grip strength among 3490 Iranian adults aged over 50 years participating in the Ardakan Cohort Study on Aging. Loneliness was measured using the 6-item De Jong Gierveld Loneliness Scale, which assesses emotional and social loneliness separately. Grip strength was evaluated using a hand dynamometer, and ordinal logistic regression analyses were performed separately by sex and age groups (middle-aged: ≤60 years; older adults: >60 years). Emotional loneliness demonstrated more consistent associations with grip strength than social loneliness. Among middle-aged women and older men, greater total and emotional loneliness were associated with higher grip strength, whereas among middle-aged men, emotional loneliness was associated with lower grip strength. No independent associations were identified among older women after full adjustment for potential confounders. Social loneliness generally showed no significant independent relationship with grip strength. These findings indicate that the association between loneliness and physical functioning is not uniform and may vary according to sex, age, and loneliness subtype. Longitudinal studies are needed to further explore these complex associations in aging populations.