Chronic pain and long‐term dementia risk in older adults: Results from a 24‐year longitudinal study

Abstract

Introduction: Chronic pain (CP) was associated with cognitive impairment in previous studies. However, the longitudinal association between CP and dementia remains under debate. We aimed to assess the prospective link between CP and long-term dementia risk in a population-based cohort of older participants, considering covariables linked to CP and cognitive functioning. Methods:The study sample was selected from the PAQUID study, an ongoing cohort of older community-dwellers aged 65 years and over at baseline; Information regarding CP and analgesics consumption was collected using questionnaires. Dementia was clinically assessed every 2 years. The population was divided into 4 groups according to CP and analgesic drugs intake (CP+/A+, CP+/A−, CP−/A+, CP −/A−). An illness-death model was used to estimate the link between CP and incident dementia risk controlled for sex, educational level, comorbidities, depression, antidepressant drugs and analgesics.Results: Five hundred ninety three participants (364 women) who completed a CP questionnaire, were included. They were followed-up over 24 years (mean followup: 11.3 years, SD 7.3). A total of 223 participants (32.5%) had CP, among them 88 (38.6%) took analgesic drugs. Compared to CP−/A− group, CP+/A+ participants had a higher risk of developing dementia in the univariate model (hazard ratio (HR) = 1.73, 95%CI:1.18-2.56; p = 0.0051). However, these results did not persist in the multivariate models (aHR = 1.23, 95%CI:0.88-1.73; p = 0.23). No significant risk for dementia were observed in CP−/A+ and CP+/A− (HR = 1.30, 95%CI:0.84-2.01; p = 0.23 and HR = 1.36, 95%CI:0.95-1.96; p = 0.09, respectively). Conclusion:Our results failed to show a significant relationship between the presence of CP and long-term dementia risk, suggesting that the cognitive decline associated with CP observed in the literature does not appear to be related to Alzheimer's disease or related disorders.

Reply to dos Santos Ferreira and Velly

“…It is worth noting that in both our studies, CP was mainly located in joints, dorso-lumbar site, and limbs, with less than 5% located in the head site. 4 Taken together, these results suggest that the presence of moderate or severe CP does not seem to be associated with accelerated cognitive decline affecting all cognitive functions but specifically processing speed, cognitive speed known to be a nonspecific marker of global brain health. Similarly, CP is not associated with long-term dementia risk.…”

“…It is worth noting that in both our studies, CP was mainly located in joints, dorso-lumbar site, and limbs, with less than 5% located in the head site. 4…”

Association between chronic pain and dementia: a systematic review and meta-analysis

“…There is growing evidence indicating that the health consequences of pain are associated with the onset and progression of dementia (Whitlock et al 2017 ; Belin and Gatt 2006 ; Wang et al 2022 ; Wang and Liu 2021 ; Khalid et al 2022 , 2020 ; Innes and Sambamoorthi 2020 ; Whitlock et al 2017 Aug 1b ; Rouch et al 2022 ; Tzeng et al 2018 ; Cheng et al 2022 ; Kao et al 2021 ; Hurh et al 2022 ; Morton et al 2019 ; Hagen et al 2014 ; Islamoska et al 2020 ; George et al 2020 ; Lee et al 2019 ; Kostov et al 2019 ; Chen et al 2018 ; Huang et al 2015 ), which is a critical issue. Neurodegenerative diseases, such as Alzheimer’s disease and related dementias, are increasingly prevalent worldwide due to the rapid aging of the global population.…”

Pain and incident cognitive impairment in very old Mexican American adults

“…Although pain has been associated with worse cognition, [2][3][4][5][6][7] cognitive impairment, 7,8 and dementia, 2,5,9 some recent studies have not found a relationship between pain and cognitive decline 10 or dementia. 11 Such mixed findings may be due to varying definitions of pain, cognitive impairment, and dementia. Pain interference, defined as pain that limits a person's daily activities, may be a more important risk factor for cognitive impairment than pain severity.…”

“…Pain, which is common among older adults, may potentially be a modifiable risk factor for dementia. Although pain has been associated with worse cognition, 2–7 cognitive impairment, 7,8 and dementia, 2,5,9 some recent studies have not found a relationship between pain and cognitive decline 10 or dementia 11 . Such mixed findings may be due to varying definitions of pain, cognitive impairment, and dementia.…”