The effect of opioids on the cognitive function of older adults: results from the Personality and Total Health through life study

Association of Regular Opioid Use With Incident Dementia and Neuroimaging Markers of Brain Health in Chronic Pain Patients: Analysis of UK Biobank

OBJECTIVES

We aimed to investigate the association of regular opioid use, compared with non-opioid analgesics, with incident dementia and neuroimaging outcomes among chronic pain patients.

DESIGN

The primary design is a prospective cohort study. To triangulate evidence, we also conducted a nested case-control study analyzing opioid prescriptions and a cross-sectional study analyzing neuroimaging outcomes.

SETTING AND PARTICIPANTS

Dementia-free UK Biobank participants with chronic pain and regular analgesic use.

MEASUREMENTS

Chronic pain status and regular analgesic use were captured using self-reported questionnaires and verbal interviews. Opioid prescription data were obtained from primary care records. Dementia cases were ascertained using primary care, hospital, and death registry records. Propensity score-matched Cox proportional hazards analysis, conditional logistic regression, and linear regression were applied to the data in the prospective cohort, nested case-control, and cross-sectional studies, respectively.

RESULTS

Prospective analyses revealed that regular opioid use, compared with non-opioid analgesics, was associated with an increased dementia risk over the 15-year follow-up (Hazard ratio [HR], 1.18 [95% confidence interval (CI): 1.08-1.30]; Absolute rate difference [ARD], 0.44 [95% CI: 0.19-0.71] per 1000 person-years; Wald χ2 = 3.65; df = 1; p <0.001). The nested case-control study suggested that a higher number of opioid prescriptions was associated with an increased risk of dementia (1 to 5 prescriptions: OR = 1.21, 95% CI: 1.07-1.37, Wald χ2 = 3.02, df = 1, p = 0.003; 6 to 20: OR = 1.27, 95% CI: 1.08-1.50, Wald χ2 = 2.93, df = 1, p = 0.003; more than 20: OR = 1.43, 95% CI: 1.23-1.67, Wald χ2 = 4.57, df = 1, p < 0.001). Finally, neuroimaging analyses revealed that regular opioid use was associated with lower total grey matter and hippocampal volumes, and higher white matter hyperintensities volumes.

CONCLUSION

Regular opioid use in chronic pain patients was associated with an increased risk of dementia and poorer brain health when compared to non-opioid analgesic use. These findings imply a need for re-evaluation of opioid prescription practices for chronic pain patients and, if further evidence supports causality, provide insights into strategies to mitigate the burden of dementia.

Chronic Pain, Analgesics, and Cognitive Status: A Comprehensive Mendelian Randomization Study

BACKGROUND

Observational studies have suggested an intricate relationship among chronic pain (CP), use of analgesics, and cognitive status, but it remains unclear whether these associations are of a causal nature.

METHODS

To investigate the causal relationship among them, summary statistics of 9 types of CP (headache, hip, neck/shoulder, stomach/abdominal, back, knee, facial, general, and multisite CP), analgesics (nonsteroidal anti-inflammatory drugs [NSAIDs], opioids, salicylic acid and derivatives, and anilides), and cognitive status (cognitive function, Alzheimer's disease [AD], vascular dementia, Lewy body dementia [LBD], and dementia) were included in this Mendelian randomization (MR) study. As both CP and analgesic use were associated with cognitive status and vice versa, we performed a bidirectional MR analysis between CP or analgesics and dementia using strong genetic instruments ( P < .001) identified from genome-wide association studies (GWAS). The inverse-variance weighted method was applied to calculate estimates. The MR estimated odds ratio (OR) was interpreted as odds of outcome per unit increase in the exposure. The Benjamini-Hochberg method was applied to adjust the P value for multiple testing, and P < .05 means statistically significant.

RESULTS

Multisite CP (MCP) was associated with worse cognitive function (OR [95% confidence interval], 0.69 [0.53-0.89], P = .043), but no significant reverse effect of cognitive status on CP was found. There were no significant associations observed between analgesics and cognitive status. Unexpectedly, patients with AD and LBD had significantly lower exposure to anilides (AD: OR = 0.97 [0.94-0.99], P = .034; LBD: OR = 0.97 [0.96-0.99], P = .012) and NSAIDs (AD: OR = 0.96 [0.93-0.98], P = .012; LBD: OR = 0.98 [0.96-0.99], P = .034).

CONCLUSIONS

Our findings indicate that an elevated number of CP sites predict future cognitive decline. Patients with dementia had lower exposure to anilides and NSAIDs, suggesting that they might not be adequately medicated for pain.

Predictors of persistent opioid use in non-cancer older adults: a retrospective cohort study

BACKGROUND

Long-term opioid use and associated adverse outcomes have increased dramatically in recent years. Limited research is available on long-term opioid use in older adults.

OBJECTIVE

We aimed to determine the incidence and predictors of long-term or persistent opioid use (POU) amongst opioid-naïve older adults without a cancer diagnosis.

METHODS

This was a retrospective cohort study using five national administrative healthcare databases in New Zealand. We included all opioid-naïve older adults (≥65 years) who were initiated on opioid therapy between January 2013 and June 2018. The outcome of interest was POU, defined as having continuously filled ≥1 opioid prescription within 91-180 days after the index opioid prescription. Multivariable logistic regression was used to examine the predictors of POU.

RESULTS

The final sample included 268,857 opioid-naïve older adults; of these, 5,849(2.2%) developed POU. Several predictors of POU were identified. The use of fentanyl (adjusted odds ratio (AOR) = 3.61; 95% confidence interval (CI) 2.63-4.95), slow-release opioids (AOR = 3.02; 95%CI 2.78-3.29), strong opioids (AOR = 2.03; 95%CI 1.55-2.65), Charlson Comorbidity Score ≥ 3 (AOR = 2.09; 95% CI 1.78-2.46), history of substance abuse (AOR = 1.52; 95%CI 1.35-1.72), living in most socioeconomically deprived areas (AOR = 1.40; 95%CI 1.27-1.54), and anti-epileptics (AOR = 2.07; 95%CI 1.89-2.26), non-opioid analgesics (AOR = 2.05; 95%CI 1.89-2.21), antipsychotics (AOR = 1.96; 95%CI 1.78-2.17) or antidepressants (AOR = 1.50; 95%CI 1.41-1.59) medication use were the strongest predictors of POU.

CONCLUSION

A significant proportion of patients developed POU, and several factors were associated with POU. The findings will enable healthcare providers and policymakers to target early interventions to prevent POU and related adverse events.

Post-COVID cognitive dysfunction: current status and research recommendations for high risk population

Post-COVID cognitive dysfunction (PCCD) is a condition in which patients with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, usually three months from the onset, exhibit subsequent cognitive impairment in various cognitive domains, and cannot be explained by an alternative diagnosis. While our knowledge of the risk factors and management strategy of PCCD is still incomplete, it is necessary to integrate current epidemiology, diagnosis and treatment evidence, and form consensus criteria to better understand this disease to improve disease management. Identifying the risk factors and vulnerable population of PCCD and providing reliable strategies for effective prevention and management is urgently needed. In this paper, we reviewed epidemiology, diagnostic markers, risk factors and available treatments on the disease, formed research recommendation framework for vulnerable population, under the background of post-COVID period.

Endogenous opiates and behavior: 2021

This paper is the forty-fourth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2021 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonizts and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Tau protein plays a role in the mechanism of cognitive disorders induced by anesthetic drugs

Cognitive disorders are mental health disorders that can affect cognitive ability. Surgery and anesthesia have been proposed to increase the incidence of cognitive dysfunction, including declines in memory, learning, attention and executive function. Tau protein is a microtubule-associated protein located in the axons of neurons and is important for microtubule assembly and stability; its biological function is mainly regulated by phosphorylation. Phosphorylated tau protein has been associated with cognitive dysfunction mediated by disrupting the stability of the microtubule structure. There is an increasing consensus that anesthetic drugs can cause cognitive impairment. Herein, we reviewed the latest literature and compared the relationship between tau protein and cognitive impairment caused by different anesthetics. Our results substantiated that tau protein phosphorylation is essential in cognitive dysfunction caused by anesthetic drugs, and the possible mechanism can be summarized as "anesthetic drugs-kinase/phosphatase-p-Tau-cognitive impairment".

A prospective cohort study to evaluate continuous wound infusion with local analgesics within an enhanced recovery protocol after colorectal cancer surgery

AIM

To reduce detrimental opioid-related side effects, minimising the postoperative opioid consumption is needed, especially in older patients. Continuous wound infusion (CWI) with local analgesics appears to be an effective opioid-sparing alternative. However, the added value of CWI to an enhanced recovery protocol after colorectal cancer (CRC) surgery is unclear. The aim of this study was to evaluate the outcomes of CWI after CRC surgery within a strictly adhered to enhanced recovery protocol.

METHODS

In this multicentre prospective observational cohort study, patients who underwent CRC surgery between May 2019 and January 2021 were included. Patients were treated with CWI as adjunct to multimodal pain management within an enhanced recovery protocol. Postoperative opioid consumption, pain scores and outcomes regarding functional recovery were evaluated.

RESULTS

A cohort of 130 consecutive patients were included, of whom 36.2% were ≥75 years. Postoperative opioids were consumed by 80 (61.5%) patients on postoperative day 0, and by 28 (21.5%), 27 (20.8%), and 18 (13.8%) patients on postoperative days 1, 2, and 3, respectively. Median pain scores were <4 on all days. The median time until first passage of stool was 1.0 (IQR: 1.0-2.0) day. Postoperative delirium occurred in 0.8%. Median length of hospital stay was 3.0 days (IQR: 2.0-5.0).

CONCLUSION

In patients treated with CWI, low amounts of postoperative opioid consumption, adequate postoperative pain control, and enhanced recovery were observed. CWI seems a beneficial opioid-sparing alternative and may further improve the outcomes of an enhanced recovery protocol after CRC surgery, which seems especially valuable for older patients.