Hospitalization, surgery, and incident dementia.

Area of Science:

• Neurology
• Epidemiology
• Genetics

Background:

• Hospitalization is a common event, but its potential impact on cognitive decline, specifically dementia and Alzheimer's disease, remains under investigation.
• Understanding risk factors for dementia is crucial for public health initiatives and personalized prevention strategies.

Purpose of the Study:

• To investigate whether hospitalization, with or without surgery, elevates the risk of developing dementia or Alzheimer's disease.
• To explore the influence of surgical versus nonsurgical hospitalizations on dementia risk.

Main Methods:

• Utilized two large Swedish samples: a clinical sample of dementia cases and controls, and a register-based sample linked to the Swedish Patient Registry.
• Employed within-pair analyses of twins and considered Apolipoprotein E (APOE) status to assess genetic susceptibility and gene-environment interactions.

Main Results:

• Nonsurgical hospitalization was associated with a higher risk of dementia compared to hospitalization with surgical intervention.
• Specific surgical procedures (thoracic, abdominal, major orthopedic) were linked to dementia risk in the register sample, while orthopedic procedures showed a link in the clinical sample.
• Analyses suggested that genetic susceptibility plays a role in the association between hospitalization and dementia, with potential gene-environment interactions observed in APOE ε4 noncarriers.

Conclusions:

• Hospitalization is confirmed as a risk factor for dementia.
• Repeated hospitalizations represent a more significant risk factor for dementia than surgical interventions.