A prospective study of knee pain, low back pain, and risk of dementia: the JAGES project

Chronic Non-cancer Pain and Associated Risks of Incident Mild Cognitive Impairment and Alzheimer's Disease and Related Dementias in Middle-Aged and Older Adults

The goal of this study is to investigate the association between chronic non-cancer pain (CNCP) and mild cognitive impairment (MCI)/Alzheimer's disease and related dementias (ADRDs) development among adults aged ≥50 using administrative claims data from a national commercial health insurance company during 2007-2017. To reduce selection bias, propensity-score matching was applied to select comparable CNCP and non-CNCP patients. Time-dependent Cox proportional-hazards regressions were conducted to estimate the hazard ratios (HRs) of incident MCI/ADRDs. Of 170,900 patients with/without CNCP, 0.61% developed MCI and 2.33% had been diagnosed with ADRDs during the follow-up period. Controlling for potential confounders, CNCP patients had a 123% increase in MCI risk (HR = 2.23; 95% CI = 1.92-2.58) and a 44% increase in ADRDs risk (HR = 1.44; 95% CI = 1.34-1.54) relative to non-CNCP patients. CNCP is a risk factor for MCI/ADRDs. Promoting awareness and improving early CNCP diagnosis in middle-aged and older adults should be incorporated into cognitive impairment and dementia prevention.

Molecular Mechanisms Linking Osteoarthritis and Alzheimer's Disease: Shared Pathways, Mechanisms and Breakthrough Prospects

Alzheimer's disease (AD) is a progressive neurodegenerative disease mostly affecting the elderly population. It is characterized by cognitive decline that occurs due to impaired neurotransmission and neuronal death. Even though deposition of amyloid beta (Aβ) peptides and aggregation of hyperphosphorylated TAU have been established as major pathological hallmarks of the disease, other factors such as the interaction of genetic and environmental factors are believed to contribute to the development and progression of AD. In general, patients initially present mild forgetfulness and difficulty in forming new memories. As it progresses, there are significant impairments in problem solving, social interaction, speech and overall cognitive function of the affected individual. Osteoarthritis (OA) is the most recurrent form of arthritis and widely acknowledged as a whole-joint disease, distinguished by progressive degeneration and erosion of joint cartilage accompanying synovitis and subchondral bone changes that can prompt peripheral inflammatory responses. Also predominantly affecting the elderly, OA frequently embroils weight-bearing joints such as the knees, spine and hips leading to pains, stiffness and diminished joint mobility, which in turn significantly impacts the patient's standard of life. Both infirmities can co-occur in older adults as a result of independent factors, as multiple health conditions are common in old age. Additionally, risk factors such as genetics, lifestyle changes, age and chronic inflammation may contribute to both conditions in some individuals. Besides localized peripheral low-grade inflammation, it is notable that low-grade systemic inflammation prompted by OA can play a role in AD pathogenesis. Studies have explored relationships between systemic inflammatory-associated diseases like obesity, hypertension, dyslipidemia, diabetes mellitus and AD. Given that AD is the most common form of dementia and shares similar risk factors with OA-both being age-related and low-grade inflammatory-associated diseases, OA may indeed serve as a risk factor for AD. This work aims to review literature on molecular mechanisms linking OA and AD pathologies, and explore potential connections between these conditions alongside future prospects and innovative treatments.

The altered hippocampal functional connectivity and serum brain-derived neurotrophic factor level predict cognitive decline in patients with knee osteoarthritis

Patients with knee osteoarthritis (KOA) often suffer from cognitive decline and increased dementia risk, but the neurobiological mechanisms remain unclear. In this study, we evaluated cognitive performance and collected brain magnetic resonance imaging (MRI) data and blood samples from cognitively normal KOA patients at baseline sessions and reevaluated their cognition after 5 years. We also collected MRI data from matched healthy controls. Results showed that KOA patients exhibited dysregulated functional connectivities between the hippocampus and thalamus/superior frontal gyrus compared with healthy controls. The altered hippocampal functional connectivities were associated with serum brain-derived neurotrophic factor (BDNF) levels and spatial expression of genes enriched in synaptic plasticity. The hippocampus-thalamus functional connectivity was significantly correlated with patients' memory scores. Moreover, the baseline hippocampus-thalamus functional connectivity and BDNF levels significantly predicted the development of cognitive decline in KOA patients in the follow-up session. Our findings provide insight into the neurobiological underpinnings of KOA and cognitive decline.

The Functions and Phenotypes of Microglia in Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide, but therapeutic strategies to slow down AD pathology and symptoms have not yet been successful. While attention has been focused on neurodegeneration in AD pathogenesis, recent decades have provided evidence of the importance of microglia, and resident immune cells in the central nervous system. In addition, new technologies, including single-cell RNA sequencing, have revealed heterogeneous cell states of microglia in AD. In this review, we systematically summarize the microglial response to amyloid-β and tau tangles, and the risk factor genes expressed in microglia. Furthermore, we discuss the characteristics of protective microglia that appear during AD pathology and the relationship between AD and microglia-induced inflammation during chronic pain. Understanding the diverse roles of microglia will help identify new therapeutic strategies for AD.

Assessment of Joint and Interactive Effects of Multimorbidity and Chronic Pain on ADRD Risk in the Elder Population

Objective

Multimorbidity and non-cancer chronic pain conditions (NCPC) are independently linked to elevated risk for cognitive impairment and incident Alzheimer's Disease and Related Dementias (ADRD)-both - We present the study of potential joint and interactive effects of these conditions on the risk of incident ADRD in older population.

Methods

This retrospective-cohort study drew baseline and 2-year follow-up data from linked Medicare claims and Medicare Current Beneficiary Survey (MCBS). Baseline multimorbidity and NCPC were ascertained using claims data. ADRD was ascertained at baseline and follow-up.

Results

NCPC accompanied by multimorbidity (vs. absence of NCPC or multimorbidity) had a significant and upward association with incident ADRD (adjusted odds ratio (AOR): 1.72, 95% CI 1.38, 2.13, p < 0.0001). Secondary analysis by number of comorbid conditions suggested that the joint effects of NCPC and multimorbidity on ADRD risk may increase with rising number contributing chronic conditions. Interaction analyses indicated significantly elevated excess risk for incident ADRD.

Contribution of pain to subsequent cognitive decline or dementia: A systematic review and meta-analysis of cohort studies

BACKGROUND

Dementia is an urgent public health problem worldwide, and the determination of the contribution of pain to cognitive decline or dementia is significant for the prevention of dementia.

OBJECTIVE

To comprehensively explore the contribution of pain to subsequent cognitive decline or dementia and analyze possible influencing factors.

DESIGN

Systematic review and meta-analysis of cohort studies.

METHODS

We systematically searched MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane Library, China National Knowledge Internet, WANFANG DATA and VIP for cohort studies from database inception to January 21, 2022. Random-effects meta-analysis was used to pool odds ratios (ORs) and 95% confidence intervals (CIs) of incident cognitive decline or dementia among patients with pain. Subgroup analyses and meta-regression were used to explore the sources of heterogeneity.

RESULTS

A total of 35 cohort studies containing 1,122,503 participants were included. As a whole, pain (OR = 1.24; 95% CI = 1.17-1.31) was a risk factor for subsequent cognitive decline or dementia; headache, migraine, tension-type headache, widespread pain, and irritable bowel syndrome, but not burning mouth syndrome, were also risk factors. Pain increased the risk of all-cause dementia (OR = 1.26; 95% CI = 1.18-1.35), Alzheimer's disease (OR = 1.28; 95% CI = 1.12-1.47), and vascular dementia (OR = 1.31; 95% CI = 1.06-1.62). Pain interference (OR = 1.42; 95% CI = 1.16-1.74) was associated with an increased risk of cognitive decline or dementia, while pain intensity was not. Pooled results from studies with sample sizes less than 2000 or with relatively low quality showed that pain did not increase the risk of cognitive decline or dementia. There was no statistically significant increase in the risk of cognitive decline or dementia in people with pain aged ≥75 years.

CONCLUSIONS

Our results demonstrated that pain increased the risk of subsequent cognitive decline or dementia. Sample size, study methodological quality, types of pain, pain severity (pain interference), and age composition of the study population may affect the relationship between pain and cognitive decline or dementia.

REGISTRATION

PROSPERO (CRD42022316406).

Longitudinal associations of pain and cognitive decline in community-dwelling older adults

Pain is inversely associated with cognitive function in older adults, but the effects of pain on cognitive decline are not fully clear. This study examined the associations of baseline pain, pain persistence, and incident pain with changes in cognition across 10 years in a sample of healthy community-dwelling older adults (n = 688; Mage = 74, SD = 6.05) from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial. While ACTIVE was a four-arm single-blind cognitive training randomized controlled trial, the present study includes only participants from the no-contact control group. Pain was examined using the Medical Outcomes Survey SF-36-Item (MOS SF-36) and cognitive tests examined simple processing speed, complex processing speed, divided and selective attention, memory, reasoning, and cognitive status. Multilevel models tested the associations of baseline pain, incident pain, and pain persistence on cognitive function and cognitive decline, adjusted for baseline age, time (years after follow-up), race, gender, education, marital status, and depressive symptoms at baseline and over time. Thirty-one percent reported pain at baseline which was related to worse baseline memory and accelerated decline in processing speed. Forty-two percent of older adults reported incident pain had accelerated decline in complex processing speed, divided attention, memory, reasoning, and cognitive status. On average, older adults reported a mean of two waves of pain persistence related to accelerated decline in memory. In sum, pain is common in community-dwelling older adults and is related to accelerated cognitive decline, especially when the incident. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Ikigai and subsequent health and wellbeing among Japanese older adults: Longitudinal outcome-wide analysis

Background

Methods

Findings

Interpretation

Funding

Psychological inflexibility and physical disability in older patients with chronic low back pain and knee pain

Aim: This study examined the associations between psychological inflexibility (PI) and physical disability (PD) among older patients with chronic low back and knee pain. Methods: Pain avoidance and cognitive fusion were assessed in outpatients as components of PI and PD, and sociodemographic and pain-related variables were used as covariates. Hierarchical multiple linear regression was used. The covariates were first entered, followed by PI. Results: Age and pain intensity had significant positive associations with PD. After adding PI, only pain avoidance was significantly and positively associated with PD. Conclusion: Focusing on pain avoidance may be effective for physical disability when acceptance and commitment therapy is administered to older patients with chronic low back and knee pain.

Increased Odds of Incident Alzheimer's Disease and Related Dementias in Presence of Common Non-Cancer Chronic Pain Conditions in Appalachian Older Adults

BACKGROUND

There is a growing concern regarding the increasing prevalence of common non-cancer chronic pain conditions (NCPCs) and their possible association with Alzheimer's disease and related dementias (ADRD). However, large population-based studies are limited, especially in Appalachian and other predominantly rural, underserved populations who suffer elevated prevalence of both NCPCs and known ADRD risk factors.

OBJECTIVES

We investigated the relation of NCPC to risk of incident ADRD in older Appalachian Medicare beneficiaries and explored the potential mediating effects of mood and sleep disorders.

METHODS

Using a retrospective cohort design, we assessed the overall and cumulative association of common diagnosed NCPCs at baseline to incident ADRD in 161,573 elders ≥65 years, Medicare fee-for-service enrollees, 2013-2015. NCPCs and ADRD were ascertained using claims data. Additional competing risk for death analyses accounted for potential survival bias.

MAIN FINDINGS

Presence of any NCPC at baseline was associated with significantly increased odds for incident ADRD after adjustment for covariates [adjusted odds ratio (AOR) = 1.26 (1.20, 1.32), p < .0001]. The magnitude and strength of this association increased significantly with rising burden of NCPCs at baseline [AOR for ≥4 vs. no NCPC = 1.65 (1.34, 2.03), p-trend = .01]. The addition of depression and anxiety, but not sleep disorders, modestly attenuated these associations [AORs for any NCPC and ≥4 NCPCs, respectively = 1.16 (1.10, 1.22) and 1.39 (1.13, 1.71)], suggesting a partial mediating role of mood impairment. Sensitivity analyses, multinomial logistic regressions accounting for risk of death, yielded comparable findings.

CONCLUSION

In this large cohort of older Appalachian Medicare beneficiaries, baseline NCPCs showed a strong, positive, dose-response relationship to odds for incident ADRD; this association appeared partially mediated by depression and anxiety. Further longitudinal research in this and other high-risk, rural populations are needed to evaluate the causal relation between NCPC and ADRD.

Persistent moderate to severe pain and long-term cognitive decline

BACKGROUND

The longitudinal association between persistent moderate to severe pain and subsequent long-term cognitive decline remains inconclusive.

METHODS

Study population came from the English Longitudinal Study of Ageing, an ongoing prospective and nationally representative cohort of community-dwelling adults aged ≥50 years in England. At waves 1 (2002/2003) and 2 (2004/2005) of the study, pain severity was measured based on pain intensity scores ranged from 0 to 10. We defined moderate to severe pain as pain intensity scores ≥5 points. Persistent moderate to severe pain was defined as participants reported moderate to severe pain at both waves 1 and 2. Standardized global cognitive Z scores derived from verbal memory, temporal orientation and semantic fluency were used as the primary outcome.

RESULTS

A total of 6,869 individuals (3,896 women; mean age: 63.9 ± 9.5 years) who have accepted twice measurements of pain at waves 1 and 2 (baseline), and at least one reassessment of cognitive function at waves 3 (2006/2007) to 8 (2016/2017), were included in this study. Each 5-point increase in the sum of pain intensity scores was associated with a faster rate of -0.009 (95% CI: -0.013 to -0.006, p < .001) in global cognitive Z scores. Compared with no pain group, persistent moderate to severe pain group was associated with a significantly faster decline rate of -0.031 SD/year (95% CI: -0.043 to -0.018), in global cognitive Z scores. The relationships of persistent moderate to severe pain with verbal memory, temporal orientation and semantic fluency were similar.

CONCLUSION

Cognitive function should be monitored in individuals with persistent moderate to severe pain.

SIGNIFICANCE

Persistent moderate to severe pain in adults age 50 and older was associated with accelerated cognitive decline over a median follow-up of 12 years. More severe pain was associated with faster cognitive decline in a dose-response pattern, and the relationship was demonstrated throughout multiple cognitive domains. While the overall effect was subtle, clinicians should be aware that older adults with persistent pain are at risk of faster cognitive decline.

Locomotive syndrome: from paradigms to clinical reality

Locomotive syndrome is an unsatisfactory condition of patients over 60 years of age who need or may require outside help in the near future due to functional deterioration of the musculoskeletal system, including pathology of bone tissue, joints, muscles and nervous tissue. In real clinical practice, one often has to deal with the following manifestations of locomotive syndrome: osteoarthritis, sarcopenia, balance disorders, chronic musculoskeletal pain. Today, there is a clear understanding that drug therapy should be long-term, include comprehensive support for muscle tissue, balance training, and mandatory cognitive-behavioral therapy. Maximum safety of long-term drug therapy can be ensured by the use of vital micronutrients, which include highly purified forms of chondroitin sulfate and glucosamine sulfate, which have a wide range of anti-inflammatory and regenerative effects.

Timeline of pain before dementia diagnosis: a 27-year follow-up study

ABSTRACT

This study examines the importance of length of follow-up on the association between pain and incident dementia. Further objective was to characterize pain trajectories in the 27 years preceding dementia diagnosis and compare them with those among persons free of dementia during the same period. Pain intensity and pain interference (averaged as total pain) were measured on 9 occasions (1991-2016) using the Short-Form 36 Questionnaire amongst 9046 (women = 31.4%) dementia-free adults aged 40 to 64 years in 1991; 567 dementia cases were recorded between 1991 and 2019. Cox regression was used to assess the association between pain measures at different time points and incident dementia and mixed models to assess pain trajectories preceding dementia diagnosis or end point for dementia-free participants. Results from Cox regression showed moderate/severe compared with mild/no total pain, pain intensity, and pain interference not to be associated with dementia when the mean follow-up was 25.0, 19.6, 14.5, or 10.0 years. These associations were evident for a mean follow-up of 6.2 years: for total pain (hazard ratio = 1.72; 95% confidence intervals = 1.28-2.33), pain intensity (1.41; 1.04-1.92), and pain interference (1.80; 1.30-2.49). These associations were stronger when the mean follow-up for incidence of dementia was 3.2 years. Twenty-seven-year pain trajectories differed between dementia cases and noncases with small differences in total pain and pain interference evident 16 years before dementia diagnosis (difference in the total pain score = 1.4, 95% confidence intervals = 0.1-2.7) and rapidly increasing closer to diagnosis. In conclusion, these findings suggest that pain is a correlate or prodromal symptom rather than a cause of dementia.

The Potential Contribution of Chronic Pain and Common Chronic Pain Conditions to Subsequent Cognitive Decline, New Onset Cognitive Impairment, and Incident Dementia: A Systematic Review and Conceptual Model for Future Research

BACKGROUND

Growing evidence suggests that chronic pain and certain chronic pain conditions may increase risk for cognitive decline and dementia.

OBJECTIVE

In this systematic review, we critically evaluate available evidence regarding the association of chronic pain and specific common chronic pain conditions to subsequent decline in cognitive function, new onset cognitive impairment (CI), and incident Alzheimer's disease and related dementias (ADRD); outline major gaps in the literature; and provide a preliminary conceptual model illustrating potential pathways linking pain to cognitive change.

METHODS

To identify qualifying studies, we searched seven scientific databases and scanned bibliographies of identified articles and relevant review papers. Sixteen studies met our inclusion criteria (2 matched case-control, 10 retrospective cohort, 2 prospective cohort), including 11 regarding the association of osteoarthritis (N = 4), fibromyalgia (N = 1), or headache/migraine (N = 6) to incident ADRD (N = 10) and/or its subtypes (N = 6), and 5 investigating the relation of chronic pain symptoms to subsequent cognitive decline (N = 2), CI (N = 1), and/or ADRD (N = 3).

RESULTS

Studies yielded consistent evidence for a positive association of osteoarthritis and migraines/headaches to incident ADRD; however, findings regarding dementia subtypes were mixed. Emerging evidence also suggests chronic pain symptoms may accelerate cognitive decline and increase risk for memory impairment and ADRD, although findings and measures varied considerably across studies.

CONCLUSION

While existing studies support a link between chronic pain and ADRD risk, conclusions are limited by substantial study heterogeneity, limited investigation of certain pain conditions, and methodological and other concerns characterizing most investigations to date. Additional rigorous, long-term prospective studies are needed to elucidate the effects of chronic pain and specific chronic pain conditions on cognitive decline and conversion to ADRD, and to clarify the influence of potential confounding and mediating factors.

Non-Cancer Chronic Pain Conditions and Risk for Incident Alzheimer's Disease and Related Dementias in Community-Dwelling Older Adults: A Population-Based Retrospective Cohort Study of United States Medicare Beneficiaries, 2001-2013

Accumulating evidence suggests that certain chronic pain conditions may increase risk for incident Alzheimer's disease and related dementias (ADRD). Rigorous longitudinal research remains relatively sparse, and the relation of overall chronic pain condition burden to ADRD risk remains little studied, as has the potential mediating role of sleep and mood disorders. In this retrospective cohort study, we investigated the association of common non-cancer chronic pain conditions (NCPC) at baseline to subsequent risk for incident ADRD, and assessed the potential mediating effects of mood and sleep disorders, using baseline and 2-year follow-up data using 11 pooled cohorts (2001-2013) drawn from the U.S. Medicare Current Beneficiaries Survey (MCBS). The study sample comprised 16,934 community-dwelling adults aged ≥65 and ADRD-free at baseline. NCPC included: headache, osteoarthritis, joint pain, back or neck pain, and neuropathic pain, ascertained using claims data; incident ADRD (N = 1149) was identified using claims and survey data. NCPC at baseline remained associated with incident ADRD after adjustment for sociodemographics, lifestyle characteristics, medical history, medications, and other factors (adjusted odds ratio (AOR) for any vs. no NCPC = 1.21, 95% confidence interval (CI) = 1.04-1.40; p = 0.003); the strength and magnitude of this association rose significantly with increasing number of diagnosed NCPCs (AOR for 4+ vs. 0 conditions = 1.91, CI = 1.31-2.80, p-trend < 0.00001). Inclusion of sleep disorders and/or depression/anxiety modestly reduced these risk estimates. Sensitivity analyses yielded similar findings. NCPC was significantly and positively associated with incident ADRD; this association may be partially mediated by mood and sleep disorders. Additional prospective studies with longer-term follow-up are warranted to confirm and extend our findings.