The Association of Osteoarthritis and Related Pain Burden to Incident Alzheimer's Disease and Related Dementias: A Retrospective Cohort Study of U.S. Medicare Beneficiaries

The Role of Depression and Anxiety in the Relationship Between Arthritis and Cognitive Impairment in Chinese Older Adults

BACKGROUND

Mental disorders and cognitive impairment are common in older patients with arthritis. While it is recognized that mental conditions may play a role in the connection between arthritis and cognitive impairment, the precise underlying relationship remains uncertain.

METHODS

The data was derived from the baseline survey of the Guangdong Mental Health Survey in South China, involving a sample of 3,764 citizens aged 65 and older. An array of aspects were explored, including socio-demographics, lifestyle behaviors, self-reported chronic conditions, depression, anxiety, and cognitive impairment. Logistic regression analyses examined the association between arthritis and cognitive impairment after adjustment for potential confounders. Serial mediation models were used to examine whether depression or anxiety played a mediating role in the arthritis-cognitive impairment linkage.

RESULTS

The prevalence rates of cognitive impairment and arthritis of the older adults were 28.9% and 12.1%, respectively. Compared to those without arthritis, participants with arthritis were at a higher risk of cognitive impairment (OR = 1.322, 95%CI: 1.022-1.709) after adjustment for socio-demographics, lifestyle behaviors, and mental health conditions. Serial mediation analyses indicated that depressive and anxiety symptoms co-played a serial mediating role in the association between arthritis and cognitive impairment (B1 = 0.025, 95%CI: 0.005-0.052; B2 = 0.050, 95%CI: 0.021-0.086).

CONCLUSIONS

Arthritis may heighten cognitive impairment risk in Chinese older adults, and the relationship was potentially mediated by depressive and anxiety symptoms. Future interventions should be considered, integrating mental health assessments into arthritis care frameworks and being alert to possible cognitive impairment.

Research progress in Alzheimer's disease and bone-brain axis

Alzheimer's disease (AD) is the most common type of cognitive impairment. AD is closely related to orthopedic diseases, such as osteoporosis and osteoarthritis, in terms of epidemiology and pathogenesis. Brain and bone tissues can regulate each other in different manners through bone-brain axis. This article reviews the research progress of the relationship between AD and orthopedic diseases, bone-brain axis mechanisms of AD, and AD therapy by targeting bone-brain axis, in order to deepen the understanding of bone-brain communication, promote early diagnosis and explore new therapy for AD patients.

Novel insights into the activating transcription factor 4 in Alzheimer's disease and associated aging-related diseases: Mechanisms and therapeutic implications

Ageing is inherent to all human beings, most mechanistic explanations of ageing results from the combined effects of various physiological and pathological processes. Additionally, aging pivotally contributes to several chronic diseases. Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding protein family, has recently emerged as a pivotal player owing to its indispensable role in the pathophysiological processes of Alzheimer's disease and aging-related diseases. Moreover, ATF4 is integral to numerous biological processes. Therefore, this article aims to comprehensively review relevant research on the role of ATF4 in the onset and progression of aging-related diseases, elucidating its potential mechanisms and therapeutic approaches. Our objective is to furnish scientific evidence for the early identification of risk factors in aging-related diseases and pave the way for new research directions for their treatment. By elucidating the signaling pathway network of ATF4 in aging-related diseases, we aspire to gain a profound understanding of the molecular and cellular mechanisms, offering novel strategies for addressing aging and developing related therapeutics.

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

PURPOSE

Dementia and chronic pain (CP) are prevalent among older adults. However, no study has systematically reviewed the association between dementia and CP. Therefore, we performed this study to gather evidence about the potential relationship between the two.

METHODS

Two authors independently searched PubMed, Embase, and Web of Science to identify all records published up to 1 September 2022 that explored the association between CP and dementia. The methodological quality of the studies was assessed using the Newcastle Ottawa Scale (NOS). A fixed or random-effects model was used to pool the risk estimates.

RESULTS

Among the initial 3296 articles retrieved, 19 were included in the review (1 cross-sectional, and 18 cohort). The pooled result showed the risk of dementia was 1.42 times higher in CP patients (HR = 1.42, 95% CI 1.23-1.64, P < 0.001). dementia and CP subtypes, gender, and age did not significantly affect the results.

CONCLUSION

Our study shows that people who suffered from CP are at an increased risk of developing dementia, regardless of gender, age, and dementia and CP subtypes.

Exploration beyond osteoarthritis: the association and mechanism of its related comorbidities

Osteoarthritis is the most prevalent age-related degenerative joint disease and a leading cause of pain and disability in aged people. Its etiology is multifaceted, involving factors such as biomechanics, pro-inflammatory mediators, genetics, and metabolism. Beyond its evident impact on joint functionality and the erosion of patients' quality of life, OA exhibits symbiotic relationships with various systemic diseases, giving rise to various complications. This review reveals OA's extensive impact, encompassing osteoporosis, sarcopenia, cardiovascular diseases, diabetes mellitus, neurological disorders, mental health, and even cancer. Shared inflammatory processes, genetic factors, and lifestyle elements link OA to these systemic conditions. Consequently, recognizing these connections and addressing them offers opportunities to enhance patient care and reduce the burden of associated diseases, emphasizing the need for a holistic approach to managing OA and its complications.

The potential molecular markers of inflammatory response in KOA with AD based on single-cell transcriptome sequencing analysis and identification of ligands by virtual screening

Alzheimer's disease (AD) and osteoarthritis (OA) are both senile degenerative diseases. Clinical studies have found that OA patients have a significantly increased risk of AD in their later life. This study hypothesized that chronic aseptic inflammation might lead to AD in KOA patients. However, current research has not yet clarified the potential mechanism between AD and KOA. Therefore, this study intends to use KOA transcriptional profiling and single-cell sequencing analysis technology to explore the molecular mechanism of KOA affecting AD development, and screen potential molecular biomarkers and drugs for the prediction, diagnosis, and prognosis of AD in KOA patients. It was found that the higher the expression of TXNIP, MMP3, and MMP13, the higher the risk coefficient of AD was. In addition, the AUC of TXNIP, MMP3, and MMP13 were all greater than 0.70, which had good diagnostic significance for AD. Finally, through the virtual screening of core proteins in FDA drugs and molecular dynamics simulation, it was found that compound Cobicistat could be targeted to TXNIP, Itc could be targeted to MMP3, and Isavuconazonium could be targeted to MMP13. To sum up, TXNIP, MMP3, and MMP13 are prospective molecular markers in KOA with AD, which could be used to predict, diagnose, and prognosis.

Peripheral extracellular vesicles in neurodegeneration: pathogenic influencers and therapeutic vehicles

Neurodegenerative diseases (NDDs) such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis epitomize a class of insidious and relentless neurological conditions that are difficult to cure. Conventional therapeutic regimens often fail due to the late onset of symptoms, which occurs well after irreversible neurodegeneration has begun. The integrity of the blood-brain barrier (BBB) further impedes efficacious drug delivery to the central nervous system, presenting a formidable challenge in the pharmacological treatment of NDDs. Recent scientific inquiries have shifted focus toward the peripheral biological systems, investigating their influence on central neuropathology through the lens of extracellular vesicles (EVs). These vesicles, distinguished by their ability to breach the BBB, are emerging as dual operatives in the context of NDDs, both as conveyors of pathogenic entities and as prospective vectors for therapeutic agents. This review critically summarizes the burgeoning evidence on the role of extracerebral EVs, particularly those originating from bone, adipose tissue, and gut microbiota, in modulating brain pathophysiology. It underscores the duplicity potential of peripheral EVs as modulators of disease progression and suggests their potential as novel vehicles for targeted therapeutic delivery, positing a transformative impact on the future landscape of NDD treatment strategies. Search strategy A comprehensive literature search was conducted using PubMed, Web of Science, and Scopus from January 2000 to December 2023. The search combined the following terms using Boolean operators: "neurodegenerative disease" OR "Alzheimer's disease" OR "Parkinson's disease" OR "Amyotrophic lateral sclerosis" AND "extracellular vesicles" OR "exosomes" OR "outer membrane vesicles" AND "drug delivery systems" AND "blood-brain barrier". MeSH terms were employed when searching PubMed to refine the results. Studies were included if they were published in English, involved human subjects, and focused on the peripheral origins of EVs, specifically from bone, adipose tissue, and gut microbiota, and their association with related diseases such as osteoporosis, metabolic syndrome, and gut dysbiosis. Articles were excluded if they did not address the role of EVs in the context of NDDs or did not discuss therapeutic applications. The titles and abstracts of retrieved articles were screened using a dual-review process to ensure relevance and accuracy. The reference lists of selected articles were also examined to identify additional relevant studies.

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.

Association of Osteoarthritis and Functional Limitations With Cognitive Impairment Among Older Adults in the United States

Objective: Given overlapping pathophysiology, this study sought to assess the association between osteoarthritis (OA), functional impairment, and cognitive impairment in the aging population. Methods: The National Health and Nutrition Examination Survey was used to identify participants >60 years of age. We analyzed multivariable associations of grouped participants that underwent cognitive function testing using linear and logistic regression, adjusting for sex, age, race, and ethnicity. Results: Of 2776 identified participants representing a population of 50,242,917, 40% did not report OA or functional limitations; 21% had OA but not functional limitations; 15% did not have OA but had functional limitations; 17% had OA and related functional limitations; and 7% had OA and non-arthritic functional limitations. OA was not independently associated with cognitive impairment. Contrarily, functional limitations were associated with cognitive impairment regardless of OA diagnosis. Discussion: Cognitive impairment is not associated with OA, but rather functional limitations, potentially guiding future intervention.

Association of APOE-ε4, Osteoarthritis, β-Amyloid, and Tau Accumulation in Primary Motor and Somatosensory Regions in Alzheimer Disease

BACKGROUND AND OBJECTIVES

One of the most prevalent chronic diseases, osteoarthritis (OA), may work in conjunction with APOE-ε4 to accelerate Alzheimer disease (AD) alterations, particularly in the primary motor (precentral) and somatosensory (postcentral) cortices. To understand the reasoning behind this, we investigated how OA and APOE-ε4 influence the accumulation of β-amyloid (Aβ) and tau accumulation in primary motor and somatosensory regions in Aβ-positive (Aβ+) older individuals.

METHODS

We selected Aβ+ Alzheimer Disease Neuroimaging Initiative participants, defined by baseline 18F-florbetapir (FBP) Aβ PET standardized uptake value ratio (SUVR) of AD summary cortical regions, who had longitudinal Aβ PET, the records of OA medical history, and APOE-ε4 genotyping. We examined how OA and APOE-ε4 relate to baseline and longitudinal Aβ accumulation and tau deposition measured at follow-up in precentral and postcentral cortical areas and how they modulate Aβ-associated future higher tau levels, adjusting for age, sex, and diagnosis and using multiple comparison corrections.

RESULTS

A total of 374 individuals (mean age 75 years, 49.2% female, 62.8% APOE-ε4 carriers) who underwent longitudinal FBP PET with a median follow-up of 3.3 years (interquartile range [IQR] 3.4, range 1.6-9.4) were analyzed, and 96 people had 18F-flortaucipir (FTP) tau PET measured at a median of 5.4 (IQR 1.9, range 4.0-9.3) years postbaseline FBP PET. Neither OA nor APOE-ε4 was related to baseline FBP SUVR in precentral and postcentral regions. At follow-up, OA rather than APOE-ε4 was associated with faster Aβ accumulation in postcentral region (β = 0.005, 95% CI 0.001-0.008) over time. In addition, OA but not the APOE-ε4 allele was strongly linked to higher follow-up FTP tau levels in precentral (β = 0.098, 95% CI 0.034-0.162) and postcentral (β = 0.105, 95% CI 0.040-0.169) cortices. OA and APOE-ε4 were also interactively associated with higher follow-up FTP tau deposition in precentral (β = 0.128, 95% CI 0.030-0.226) and postcentral (β = 0.124, 95% CI 0.027-0.223) regions.

DISCUSSION

This study suggests that OA was associated with faster Aβ accumulation and higher Aβ-dependent future tau deposition in primary motor and somatosensory regions, providing novel insights into how OA increases the risk of AD.

Improving diagnosis and treatment of knee osteoarthritis in persons with type 2 diabetes: development of a complex intervention

BACKGROUND

Symptomatic knee osteoarthritis (OA) commonly co-occurs in people with type 2 diabetes (T2DM) and increases the risk for diabetes complications, yet uptake of evidence-based treatment is low. We combined theory, stakeholder involvement and existing evidence to develop a multifaceted intervention to improve OA care in persons with T2DM. This was done in partnership with Arthritis Society Canada to leverage the existing infrastructure and provincial funding for community arthritis care.

METHODS

Each step was informed by a User Advisory Panel of stakeholder representatives, including persons with lived experience. First, we identified the target groups and behaviours through consulting stakeholders and current literature. Second, we interviewed persons living with T2DM and knee OA (n = 18), health professionals (HPs) who treat people with T2DM (n = 18) and arthritis therapists (ATs, n = 18) to identify the determinants of seeking and engaging in OA care (patients), assessing and treating OA (HPs) and considering T2DM in OA treatment (ATs), using the Theoretical Domains Framework (TDF). We mapped the content to behavioural change techniques (BCTs) to identify the potential intervention components. Third, we conducted stakeholder meetings to ascertain the acceptability and feasibility of intervention components, including content and modes of delivery. Fourth, we selected intervention components informed by prior steps and constructed a programme theory to inform the implementation of the intervention and its evaluation.

RESULTS

We identified the barriers and enablers to target behaviours across a number of TDF domains. All stakeholders identified insufficient access to resources to support OA care in people with T2DM. Core intervention components, incorporating a range of BCTs at the patient, HP and AT level, sought to identify persons with knee OA within T2DM care and refer to Arthritis Society Canada for delivery of evidence-based longitudinal OA management. Diverse stakeholder input throughout development allowed the co-creation of an intervention that appears feasible and acceptable to target users.

CONCLUSIONS

We integrated theory, evidence and stakeholder involvement to develop a multifaceted intervention to increase the identification of knee OA in persons with T2DM within diabetes care and improve the uptake and engagement in evidence-based OA management. Our partnership with Arthritis Society Canada supports future spread, scalability and sustainability. We will formally assess the intervention feasibility in a randomized pilot trial.

Pain as a Protective Factor for Alzheimer Disease in Patients with Cancer

OBJECTIVE

Alzheimer disease (AD) and cancer have been reported to be inversely correlated in incidence, but the mechanism remains elusive.

METHODS

A case-control study was conducted, based on the SEER (Surveillance, Epidemiology, and End Results) Research Plus data, to evaluate 12 factors in patients with cancer.

RESULTS

Severe pain was related to reduced AD risk, while older age at cancer diagnosis, female, longer survival years after tumor diagnosis, more benign/borderline tumors, less cancer-directed surgery, and more chemotherapy were associated with higher AD risk. In addition, patients of different races or with different cancer sites were associated with different risks of getting AD. Cases had a higher prevalence of severe pain than controls in all race and cancer site subgroups, except for in digestive cancer, where the result was the opposite.

CONCLUSIONS

This study indicated pain as a novel protective factor for AD in patients with cancer. The mechanism behind it may provide new perspective on AD pathogenesis and AD-cancer association, which we discussed in our own hypothesis of the mechanism of pain action. In addition, digestive cancer pain had an opposite impact on AD risk from other cancer pains, which suggests the uniqueness of digestive system in interacting with the central nervous system.

The Association Between Osteoarthritis with Risk of Dementia and Cognitive Impairment: A Meta-Analysis and Systematic Review

Background: The relationship between osteoarthritis (OA) and risk of dementia and cognitive impairment (CIM) has long been debated; however, uncertainties still persist. Objective: The aim of our present meta-analysis and systematic review was to roundly illuminate the association between OA and the risk of dementia and CIM. Methods: We identified relevant studies by searching PubMed, Embase, and Web of Science up to October 2021. The relative risk (RR) or odds ratio (OR) with 95% confidence interval (CI) were aggregated using random-effects methods. Credibility of each meta-analysis was assessed. Meta-regression and subgroup analyses were conducted. Publication bias was explored using funnel plot. Results: Of 21,925 identified literatures, 8 were eligible for inclusion in the systematic review and 19 observational studies involving 724,351 individuals were included in the meta-analysis. The risk of developing dementia and CIM among OA patients was demonstrated in 11 prospective studies (RR = 1.42, 95% CI = 1.07–1.86, I2 = 98.9%, p <  0.001), 2 retrospective cohort studies (RR = 1.35, 95% CI = 1.19–1.52, I2 = 61.0%, p = 0.109), 3 retrospective case-control studies (OR = 1.21, 95% CI = 0.96–1.53, I2 = 95.2%, p <  0.001), and 4 cross-sectional studies (OR = 1.51, 95% CI = 1.09–2.09, I2 = 75.8%, p = 0.006). Meta-regression analyses did not find any valid moderators. Heterogeneity in subgroup analyses for population age, OA location, year of publication, outcome type, adjusted for BMI, depression, and comorbidity decreased to zero. No significant evidence of publication bias was found. Conclusion: OA associated with an increased risk of dementia and CIM. Effective interventions in OA patients may decrease new incidence of dementia or CIM.

Chronic Pain in the Elderly: Mechanisms and Perspectives

Chronic pain affects a large part of the population causing functional disability, being often associated with coexisting psychological disorders, such as depression and anxiety, besides cognitive deficits, and sleep disturbance. The world elderly population has been growing over the last decades and the negative consequences of chronic pain for these individuals represent a current clinical challenge. The main painful complaints in the elderly are related to neurodegenerative and musculoskeletal conditions, peripheral vascular diseases, arthritis, and osteoarthritis, contributing toward poorly life quality, social isolation, impaired physical activity, and dependence to carry out daily activities. Organ dysfunction and other existing diseases can significantly affect the perception and responses to chronic pain in this group. It has been proposed that elderly people have an altered pain experience, with changes in pain processing mechanisms, which might be associated with the degeneration of circuits that modulate the descending inhibitory pathways of pain. Aging has also been linked to an increase in the pain threshold, a decline of painful sensations, and a decrease in pain tolerance. Still, elderly patients with chronic pain show an increased risk for dementia and cognitive impairment. The present review article is aimed to provide the state-of-art of pre-clinical and clinical research about chronic pain in elderly, emphasizing the altered mechanisms, comorbidities, challenges, and potential therapeutic alternatives.

Association between systemic rheumatic diseases and dementia risk: A meta-analysis

BACKGROUND AND AIMS

Epidemiological studies have been conducted on the relationship between systemic rheumatic diseases (SRDs) and dementia. Therefore, we focused on determining the extent of alliances bounded by SRDs, along with the risk of dementia.

MATERIALS AND METHODS

Two independent reviewers assessed all studies retrieved from the PubMed, EMBASE, Scopus, and Web of Science databases between January 1, 2000 and November 30, 2021. Only observational studies that estimated the possibility of dementia in participants with SRD were considered. The random-effects model was applied to forecast pooled risk ratios (RRs) and 95% confidence intervals (CI). Heterogeneity among the studies was evaluated using the Q and I² statistics. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Funnel plots were used to calculate the risk of bias.

RESULTS

Seventeen observational studies with 17,717,473 participants were recruited. Our findings showed that among the participants with SRDs, those with osteoarthritis, systemic lupus erythematosus, and Sjogren's syndrome were highly related to an elevated risk of dementia (pooled RR: 1.31; 95% CI: 1.15-1.49, p<0.001; pooled RR: 1.43; 95% CI: 1.19-1.73, p<0.001; and pooled RR: 1.26; 95% CI: 1.14-1.39, p<0.001, respectively). However, participants with rheumatoid arthritis (RA) were not associated with an increased risk of dementia (pooled RR: 0.98; 95% CI: 0.90-1.07, p<0.001).

CONCLUSION

This systematic review and meta-analysis demonstrated an increased dementia risk among SRDs participants, except for RA.

Prospective Evaluation of the Association Between Arthritis and Cognitive Functions in Middle-Aged and Elderly Chinese

Background: Assessing the relation between arthritis and cognitive impairment could expand the understanding of health consequences of arthritis. The aim was to prospectively examine the association between arthritis and cognitive functions among middle-aged and elderly Chinese.

Methods: Our analyses were based on data from the nationwide China Health and Retirement Longitudinal Study (2011–2016). Arthritis was ascertained by self-reported doctor diagnosis during the baseline survey. Cognitive functions were evaluated in three domains including episodic memory, mental status, and global cognition. Linear mixed models were employed to assess the association between baseline arthritis and cognition functions.

Results: Of 7,529 Chinese adults, 49.79% were men, and mean age was 57.53 years. During a follow-up of 4 years, participants with baseline arthritis showed lower scores of episodic memory [β = −0.08; 95% confidence interval (CI): −0.14, −0.03], mental status (β = −0.14; 95% CI: −0.22, −0.05), and global cognition (β = −0.22; 95% CI: −0.34, −0.11), compared to those without arthritis. In addition, participants with arthritis showed increased rates of decline in mental status and global cognition by 0.04 (95% CI: 0.01, 0.08) and 0.05 (95% CI: 0.01, 0.09) units per year, respectively.

Conclusion: Arthritis was associated with subsequent risk of poorer cognitive functions and slightly faster declines in cognitive functions among Chinese middle-aged and elderly adults. Our findings should be confirmed in future large prospective studies in Chinese and other populations.

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.

Risk of comorbidities following physician-diagnosed knee or hip osteoarthritis: a register-based cohort study

OBJECTIVE

To estimate the risk of developing comorbidities in patients after physician-diagnosed knee or hip osteoarthritis (OA).

DESIGN

Cohort study using Swedish longitudinal healthcare register data; we studied residents in the Skåne region aged ≥35 years at January 1, 2010 free from diagnosed hip or knee OA (n= 548,681). We then identified subjects with at least one new diagnosis of knee or hip OA (incident OA) between 2010 and 2017 (n=50,942 considered exposed). Subjects without diagnosed OA were considered unexposed. From January 2010 both unexposed and exposed subjects were observed for the occurrence of 18 different pre-defined comorbidities until either relocation outside of the region, death, occurrence of the comorbidity, or December 2017, whichever came first. We calculated unadjusted and adjusted hazard ratios (HR, aHR) of comorbidities using Cox models with knee and hip OA as time-varying exposures.

RESULTS

Subjects with incident knee or hip OA had 7% to 60% higher adjusted hazards (aHR between 1.07 to 1.60), of depression, cardiovascular diseases, back pain, and osteoporosis than individuals without an OA diagnosis. An increased risk of diabetes was found only for knee OA (aHR 1.19, 95% CI 1.13-1.26). For the rest of the diagnoses, we found either no increased risk or estimates with wide confidence intervals, excluding clear interpretations of the direction or size of effects.

CONCLUSIONS

Incident physician-diagnosed knee and hip OA is associated with increased risk of depression, cardiovascular diseases, back pain, osteoporosis, and diabetes. However, the latter only for knee OA.

Comprehensive Management of Daily Living Activities, behavioral and Psychological Symptoms, and Cognitive Function in Patients with Alzheimer's Disease: A Chinese Consensus on the Comprehensive Management of Alzheimer's Disease

Alzheimer's disease (AD) is the most common cognitive disorder in the elderly. Its main clinical manifestations are cognitive decline (C), behavioral and psychological symptoms (B), and a decline in the activities of daily living (A), also known as ABC symptoms. Early identification and evaluation of ABC symptoms are helpful for establishing the accurate diagnosis, comprehensive treatment, and prognosis of AD. To guide Chinese clinical practice for optimization of the comprehensive management of AD, in 2018, The Academy of Cognitive Disorder of China gathered 22 neurologists and gerontologists in China to build a consensus on the comprehensive management of AD. Based on a review of the evidence, the consensus summarizes the pathogenesis, pathological changes, clinical manifestations, evaluation, diagnosis, drug and non-drug treatment, and patient care for AD. Focus group discussion was used to establish a flowchart of comprehensive ABC management for AD patients. The new consensus provides a feasible AD management process for clinicians.

Intermittent fasting with a high-protein diet mitigated osteoarthritis symptoms by increasing lean body mass and reducing inflammation in osteoarthritic rats with Alzheimer's disease-like dementia

Menopausal women are susceptible to osteoarthritis(OA) and memory impairment. We hypothesised that Alzheimer's-like disease(AD) exacerbates OA and that intermittent fasting(IMF) with a high-protein(H-P) diet would enhance memory function and relieve OA symptoms in oestrogen-deficient animals induced AD and OA. The action mechanism was also explored. Ovariectomised Sprague-Dawley rats were fed high-fat(H-F) or H-P diets for 2 weeks, and then they had a hippocampal infusion of β-amyloid(25-35) for 4 weeks to induce AD and an injection of monoidoacetate(MIA) into the articular cartilage to induce OA. Non-AD groups had non-AD symptoms by hippocampal amyloid-β(35-25) infusion. IMF suppressed memory impairment in AD rats, especially those fed H-P diets. Compared with non-AD, AD exacerbated OA symptoms, including swelling, limping, slowed treadmill running speed, and uneven weight distribution in the left leg. The exacerbations were linked to increased inflammation and pain, but IMF and H-P lessened the exacerbation. Lean body mass(LBM) decreased with AD, but H-P protected against LBM loss. Histological examination of the knee joint revealed the degree of the cellular invasion into the middle zone, and the changes in the tidemark plateau were greatest in the AD-AL with H-F, while non-AD-IMF improved the cellular invasion to as much as non-AD-AL. H-P reduced the infiltration into the middle zone of the knee and promoted collagen production. In conclusion, AD exacerbated the articular cartilage deterioration and memory impairment, and IMF with H-P alleviated the memory impairment and osteoarthritic symptoms by decreasing hippocampal amyloid-β deposition and proinflammatory cytokine expressions and by increasing LBM.

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.