Association between onset and disappearance of pain and changes in physical activity among older adults - longitudinal evidence from the German Ageing Survey.

BACKGROUND Physical activity (PA) is important for healthy ageing. Nonetheless, recommended PA guidelines from the World Health Organization are not met by many older adults. To increase PA, influencing factors have been investigated. But it is still unknown how the onset or disappearance of pain within an individual is associated with different PA intensities in older men and women. METHOD We used longitudinal data from the nationwide representative German Ageing Survey, waves 2014 and 2017 (analytical sample, n = 6194, 45% women). PA was assessed with questions on low, moderate, and vigorous PA per week and converted into metabolic equivalent of task (MET) values. Pain was dichotomized from a 5-point scale into no pain versus some pain. The association between the onset or disappearance of pain from 2014 to 2017 on total, vigorous, moderate, and low PA was investigated using sex stratified asymmetric fixed effects models. RESULTS The onset of pain in older men (s = 977.84, P = 0.041), and the disappearance of pain in older women (s = 1531.69, P = 0.025), were associated with increased total PA. The results for men were driven by increases in vigorous (s = 592.62, P = 0.035) PA, while the change in women was driven by low (s = 242.16, P = 0.020) and moderate (s = 496.48, P = 0.034) PA intensities. However, the observed differences between men and women were not statistically significant. CONCLUSION The divergent associations between the onset and disappearance of pain and PA, driven by different PA intensities in men and women, suggest the existence of factors such as PA intensity influencing the association.