Pain and its association with device-measured activity patterns in older adults: age and sex differences in a population-based cross-sectional study

BACKGROUND: While pain has been widely studied in relation to physical activity (PA), less is known about how habitual patterns of activity relate to pain in older adults. This study examined associations between pain characteristics and activity patterns in older adults, and whether these associations differ by age and sex. METHODS: Cross-sectional data from 665 older adults in the Swedish National Study on Aging and Care-Kungsholmen (SNAC-K, 2016-2019) were analysed. PA and sedentary behaviour were measured using the activPAL3™ accelerometer, and pain characteristics were collected via questionnaires. Latent Class Analysis identified three activity classes (named Active-, Balanced and Sedentary Movers) based on steps/day, sedentary time- and bout duration, light PA, moderate-to-vigorous PA, and number of light-/moderate-to-vigorous PA events. Multinomial logistic regression assessed associations between activity classes and pain, testing modification by age and sex. RESULTS: In the total sample, higher pain intensity was associated with membership in the Sedentary Movers class (RRR: 2.16, 95% CI: 1.06, 4.40, p = 0.034), characterised by low PA and predominant sedentary behaviour, compared with the Active Movers (reference), characterised by high activity levels with substantial light- and moderate-to-vigorous PA. The interaction analysis displayed that associations were concentrated in women and the oldest-old (≥ 80 years). No significant associations were observed for pain and the Balanced Movers vs. Active Movers classes. CONCLUSION: Activity patterns characterised by high sedentary behaviour were associated with specific pain characteristics in older adults, particularly among women and the oldest-old. Longitudinal studies are needed to clarify the direction of these associations.