Regular opioid use may increase dementia risk

In a study published in Alzheimer's & Dementia, a team led by Dr. SHA Feng from the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, collaborating with Dr. Jed A. Barash from the Massachusetts Veterans Home at Chelsea and Prof. W. Andrew Kofke from the University of Pennsylvania, found that regular opioid use is associated with an increased risk of dementia, particularly vascular dementia.

Chronic non-cancer pain (CNCP) is defined as any painful condition that persists for more than three months and is unrelated to malignancy. Opioid use for CNCP became widespread in the mid-1990s. Inappropriate prescribing, dependence, and misuse of high-potency opioids have raised public health concerns.

Previous studies have suggested that opioid use may affect the endogenous opioid system and potentially impair the hippocampus and other central nervous system regions, increasing the risk of cognitive decline and dementia.

In this study, the researchers conducted a prospective cohort study involving 197,673 individuals with CNCP aged 37 to 73 from the UK Biobank, with a mean follow-up of 13.8 years. They applied multiple Cox, linear, and logistic regression models, which control for potential confounding factors, to explore the associations between regular opioid use and incident dementia, neuroimaging outcomes, and cognitive measures.

The researchers found that regular opioid use was associated with a 20% higher risk of all-cause dementia compared with taking analgesics. Participants who regularly used strong opioids had a over 70% increased risk of dementia, and those taking non-opioid analgesics showed a risk level similar to the non-users. Besides, a significant association between opioid use and vascular dementia (VD) was observed.

Through neuroimaging analyses, the researchers found that regular use of strong opioids was linked to reduced total brain volume (TBV), white matter volume (WMV), and hippocampal volume (HV). They also found that opioid use was associated with lower fluid intelligence, but not significantly associated with prospective memory decline.

This study underscores the importance of considering both opioid potency and cumulative exposure when evaluating the associations between opioid use and the risk of dementia or other adverse outcomes. This study provides valuable insights into the strategies for addressing the complex interplay between chronic pain, analgesic use, and cognitive impairment.