# Trajectory of cardiometabolic disease-related hospitalizations before and after dementia diagnosis

## TL;DR

People diagnosed with dementia had more hospitalizations related to heart and metabolic diseases up to four years before diagnosis, suggesting these hospitalizations might be an early sign of dementia.

## Contribution

This study reveals that CMD-related hospitalizations increase before dementia diagnosis, offering new insights into the early healthcare burden of dementia.

## Key findings

- CMD-related hospitalization rates increased 4 years before dementia diagnosis and decreased 3 years after.
- People with dementia had more CMD-related hospitalizations and longer stays in the five years before diagnosis.
- Male sex, smoking, obesity, and hypertension were linked to higher CMD-related hospitalization rates in dementia patients.

## Abstract

Cardiometabolic diseases (CMDs) including type 2 diabetes, heart disease, and stroke often co-occur with dementia, but the impact of dementia on hospitalizations related to CMDs remains unknown. We aimed to map the trajectory of CMD-related hospitalization before and after dementia diagnosis and to further identify factors of CMD-related hospitalization. Within the Swedish Twin Registry, 1657 participants aged ≥65 with incident dementia were matched with 1657 dementia-free participants using propensity scores. Participants were followed for up to 20 years to detect CMD-related hospitalizations. Dementia and CMD-related hospitalizations (planned and unplanned) were identified from medical records. Potential related factors included age, sex, education, marital status, smoking, drinking, physical activity, body mass index, and hypertension. Data were analyzed using Poisson regression and generalized estimating equation models. Compared to the controls, the incidence of CMD-related hospitalization among people with dementia started to increase from 4 years before (incidence rate ratio [IRR] 1.25, 95% confidence interval [CI] 1.00-1.57) and started to decrease 3 years after, the diagnosis (IRR 0.74, CI 0.58-0.94). People with dementia had a greater number of CMD-related hospitalizations (IRR 1.19, CI 1.04-1.36) and longer cumulative length of stay (IRR 1.27, CI 1.04-1.56) in the five years before dementia diagnosis, but these rates decreased after the diagnosis. Male sex, smoking, obesity, and hypertension were associated with further increases in CMD-related hospitalization among people with dementia. Our findings suggest that the healthcare burden increases even before the diagnosis of dementia, and CMD-related hospitalization may be an early sign of the future onset of dementia.