Impaired sleep, depressive symptoms, and pain as determinants of physical activity and exercise intervention adherence: an exploratory analysis of a randomized clinical trial

Background Physical activity (PA) and exercise interventions offer health benefits can reduce dementia risk. However, there might be barriers to engage in PA, such as sleep problems, depressive symptoms and pain, which are common complaints with older adults. We investigated sleep duration, sleep quality, depressive symptoms, and pain at baseline as potential determinants of: (i) adherence to the exercise intervention component of a 2-year multidomain lifestyle intervention; (ii) intervention's effect on PA after 2 years; and (iii) overall PA after 2 years (exploratory analyses). Methods The FINGER trial included 1259 individuals at risk for dementia, aged 60-77 years who were randomized (1:1) to a multidomain lifestyle intervention (exercise, diet, cognitive training, vascular risk factor management) or a control (regular health advice) group. Logistic regression analyses were used with exercise adherence (adherent: >= 66% participation) or self-reported PA (active: >= 2 times/week) as outcomes, adjusted for relevant baseline characteristics. Data on PA at baseline and at 2-years were available for 1100 participants. Results Adherence to the exercise intervention was less likely with sleep duration < 6 h or >= 9 h per night compared with 7-8 h. OR (95% CI) were 0.46 (0.21-0.99) and 0.38 (0.20-0.74), respectively. The intervention group was more likely to be physically active than the control group at two years (OR 1.87, 95% CI 1.36-2.55). This intervention benefit did not significantly vary by baseline sleep duration, depressive symptoms, or pain (p > 0.3 for all interactions). Regardless of randomization group, those sleeping < 6 h were less likely to be physically active at two years, compared with participants sleeping 7-8 h (OR 0.36, 95% CI 0.18-0.72). Depressive symptoms or pain were not related to PA at two years. Conclusions Older adults with sleep problems, depressive symptoms, or pain may benefit from lifestyle interventions. However, both short and long sleep duration can pose barriers to engaging in exercise intervention and should be carefully considered when designing strategies to promote PA among older populations at risk for dementia.