New Insights into Dementia and Mortality

New insights into the link between dementia and mortality have emerged from a comprehensive investigation utilizing case-control and co-twin control models. Conducted by researchers using data from the Swedish Twin Registry, the study explored the interplay of genetic and environmental influences on the association between dementia and increased mortality risk. This study was published in the journal Alzheimer’s & Dementia by Jung Yun Jang and colleagues.

The study encompassed 987 twins diagnosed with dementia and 2938 age- and sex-matched controls. Results revealed that individuals with dementia exhibited a significantly greater mortality risk compared to their matched controls, with a hazard ratio (HR) of 2.02. However, the mortality risk, while still elevated, was notably lower in twins from discordant pairs—where one had dementia and the other did not—particularly in identical twins. For instance, comparing identical twins with dementia to their non-dementia co-twin controls yielded an HR of 1.48.

The findings, based on twin pairs discordant for dementia, suggest that genetic factors might play a significant role in influencing the association between dementia and mortality. Interestingly, identical twins with dementia and their non-dementia co-twins displayed a similar survival time, implying a potential genetic basis influencing the link between dementia and mortality.

Study Details

• Participants: 987 twins diagnosed with dementia and 2938 matched controls
• Co-twin Control Design: Analyzed 90 monozygotic (MZ) and 288 dizygotic (DZ) twin pairs discordant for dementia
• Mortality Risk Comparisons:
  • Twins with dementia had a higher mortality risk compared to matched controls (HR = 2.02)
  • Mortality risk was notably lower in discordant twin pairs, particularly among identical twins (HR = 1.48)

These intriguing findings prompt further exploration into the genetic underpinnings influencing the association between dementia and mortality. Understanding the role of genetic factors in this link may open avenues for more targeted interventions or personalized approaches in managing dementia-related mortality risks.

The study, shedding light on the potential genetic influence on dementia-related mortality, underscores the need for continued research to elucidate the intricate mechanisms driving this association.

Reference

Jang, J. Y., Beam, C. R., Karlsson, I. K., Pedersen, N. L., & Gatz, M. Dementia and mortality in older adults: A twin study. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, 2023. https://doi.org/10.1002/alz.13553