Pain and incident cognitive impairment in very old Mexican American adults

Studies have investigated the association between pain and cognitive impairment among older adults, but the findings are mixed. We assessed the relationship of activity-limiting pain (pain interference) with incident cognitive impairment and the mediating effect of depressive symptoms among Mexican American adults aged ≥80.

Data were taken from the Hispanic Established Population for the Epidemiological Study of the Elderly (2010-2016). Pain interference, or pain that limited daily activities in the last 12 months, was categorized into none, untreated pain interference, and treated pain interference. Cognitive impairment was defined as scoring <21 on the Mini-Mental State Examination and difficulty with at least one instrumental activity of daily living. We used general estimation equations to assess this relationship between pain and incident cognitive impairment over the 6-year period (n = 313).

Participants reporting both untreated and treated pain interference had higher odds of incident cognitive impairment than those reporting no pain or pain interference (untreated adjusted odds ratio [aOR]: 2.18; 95% confidence interval [CI]: 1.09-4.36; treated aOR: 1.99; 95% CI: 1.15-3.44). Depressive symptoms explained 15.0% of the total effect of untreated pain and 25.3% of treated pain.

Among very old Mexican American adults, both treated and untreated pain interference was associated with incident cognitive impairment. This association was partially mediated by depressive symptoms, underscoring a need for depression screening in patients with chronic pain. Future work is needed to examine mechanistic/causal pathways between pain and subsequent cognitive impairment and the role of pharmacological and non-pharmacological treatments in these pathways.