UC Davis

There is increasing interest in identifying modifiable risk factors for cognitive decline and dementia. Emerging evidence suggests that chronic pain, also known as persistent pain, may be a potentially modifiable risk factor for cognitive decline and dementia. Previous studies, however, provided mixed findings on the relationship between persistent pain and cognitive decline in older adults; and few studies specifically examined pain interference and domain-specific cognition. Notably, there is a paucity of research examining how the intersection of persistent pain and cognitive decline affects older adults belonging to ethnoracially diverse groups. As such, the primary aim of this dissertation was to investigate the cross-sectional associations between pain interference and cognitive performance in the specific cognitive domains of verbal episodic memory and executive functioning among older adults aged 65 and older. A secondary aim of the study was to examine potential effect modification from sex, ethnoracialized group membership, and educational attainment.

Data for this secondary analysis came from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study, a prospective cohort of ethnoracially-diverse, community-dwelling older adults aged 65 and older residing in Northern California. The analytic sample comprised 952 participants. The outcome measures were verbal episodic memory and executive functioning. The primary exposure of interest was pain interference, which was defined as having persistent pain that made it difficult to do usual activities such as household chores or work. Multiple linear regression was used to examine the cross-sectional associations between pain interference and verbal episodic memory and executive functioning, while controlling for important sociodemographic, health-related, and lifestyle variables.Compared with participants without persistent pain or without pain interference, older adults in the pain interference group were more likely to be women; have non-Latinx Black group membership; have lower mean years of educational attainment; and more likely to be unpartnered. In adjusted multiple linear regression models, the effect of having pain interference was statistically significant and negatively associated with executive functioning z-score. However, the study did not find a significant association between pain interference and verbal episodic memory. Additionally, moderation analysis indicated that the relationship between pain interference and executive functioning score did not appear to differ statistically by sex, ethnoracialized group membership, or by educational attainment.

In this prospective cohort of diverse older adults, this study found a negative association between pain interference and executive functioning composite score, and, more specifically, a negative association between pain interference and phonemic (letter) fluency score. While this study contributes to the growing body of research on the relationship of pain and cognitive function in older adults, additional research is warranted to elucidate the complex factors and potential causal mechanisms of the relationship.