Pain and cognitive function in Korean older adults aged 60 years or more: A retrospective longitudinal study.

Abstract

To elucidate the relationship between pain and cognitive decline in adults aged ≥60 years using data from the Korean Longitudinal Study of Aging survey. We included 3,287 older adults aged ≥60 years with a Korean Mini-Mental State Examination score ≥24. We assessed the presence of pain and pain interference using self-administered questionnaires. Pain interference was determined based on whether the pain limited the participants' activities of daily living. According to this assessment, participants were categorized as no pain, low-impact pain, and high-impact pain. Cognitive function was assessed using the Mini-Mental State Examination and classified into 3 groups: normal, cognitive impairment, and suspected dementia. Potential confounding factors, including pain × survey year, were adjusted in the analyses. We also performed subgroup analyses of participants experiencing pain to elucidate the association between pain interference, suspected dementia, and cognitive impairment. A significant difference in the Mini-Mental State Examination scores was observed between individuals with and without pain (P < .001). Pain remained negatively associated with the Mini-Mental State Examination score through the first to the eighth wave even after adjusting for confounding factors (β = -1.170, 95 % confidence interval (CI): -0.243, -0.097). Compared to the absence of pain, the presence of pain increased the odds of suspected dementia and cognitive impairment by approximately 1.6 and 1.4 times, respectively (odds ratio [OR] = 1.56, 95% CI: 1.26, 1.93; OR = 1.36, 95% CI: 1.20, 1.54). Compared to low-impact pain, high-impact pain increased the odds of suspected dementia and cognitive impairment by approximately 2.1and 1.5 times, respectively (OR = 2.12, 95% CI: 1.76, 2.56; OR = 1.47, 95% CI: 1.31, 1.65). Pain was negatively associated with Mini-Mental State Examination scores in Korean older adults aged ≥60 years and increased the odds of suspected dementia and cognitive impairment. Furthermore, individuals with high-impact pain exhibited higher risks of both suspected dementia and cognitive impairment than those with low-impact pain.