Bodily pain in physical function and the role of physical activity among community-dwelling adults aged 50-69 years in Ghana

Background: Older adults who experience pain are likely to report higher functional limitations (FL) and lower physical activity (PA) levels. However, the extent to which PA explains the association of pain with FL is largely unknown, particularly in low- and middle-income countries. This study estimates whether and how much pain in FL is mediated by PA engagement.

Methods: We used cross-sectional data from 770 adults aged 50–69 years who participated in the Aging, Health, Psychological Well-being, and Health-seeking Behavior Study in Ghana. FL and pain characteristics were defined using the Medical Outcomes Study Short Form-36. PA was assessed by the International Physical Activity Questionnaire short form. Bootstrapped mediation analyses estimated the direct and indirect hypothesized associations. The control variables included age, sex, residential type, level of education, monthly income, social isolation, emotional distress, multimorbidity, and self-rated health.

Results
After adjusting for potential confounders, higher pain interference (β=0.091, p<0.05) and higher pain severity (β=0.075, p<0.05) were associated with greater FL. The bootstrapping analyses showed that PA mediated the pain interference-FL association, accounting for ~58% (β=0.124, Boots 95%CI=0.078-0.175) of the total effect (β=0.215, Boots 95%CI=0.095-0.335). Similarly, PA mediated the association of pain severity with FL, accounting for ~37% (β=0.044, Boots 95%CI=0.001-0.094) of the overall effect (β=0.119, Boots 95%CI=-0.011-0.249).

Conclusions: Our data suggest that the higher pain severity and pain interference may lead to higher FL in middle and old age, and the associations are partially explained by PA. Effective and low-cost PA participation could be targeted in efforts to reduce the effect of pain on physical functioning among middle-aged and older adults.