Trajectory of Cardiometabolic Disease–Related Hospitalizations Before and After Dementia Diagnosis: A Matched Cohort Study

Objectives

Dementia is associated with increased health care use; however, the timing of hospitalizations in relation to the development of dementia remains unclear. 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.

Design

Matched cohort study.

Setting and Participants

Within the Swedish Twin Registry, 1657 participants aged ≥65 years (58.8% women) with incident dementia were matched with 1657 dementia-free participants using propensity scores.

Methods

Participants were followed for up to 20 years to detect CMD-related hospitalizations. Dementia and CMD-related hospitalizations (both 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.

Results

Compared with the control patients, the incidence of CMD-related hospitalization among people with dementia started to increase from 4 years before [incidence rate ratio (IRR), 1.25; 95% CI, 1.00-1.57], and started to decrease 3 years after, the diagnosis (IRR, 0.74; 95% CI, 0.58-0.94). People with dementia had a greater number of CMD-related hospitalizations (IRR, 1.19; 95% CI, 1.04-1.36) and longer cumulative length of stay (IRR, 1.27; 95% CI, 1.04-1.56) in the 5 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.

Conclusions and Implications

Patterns of CMD-related hospitalization change over the course of dementia development. Our findings suggest that the health care burden increases even before the diagnosis of dementia, and CMD-related hospitalization may be an early sign of the future onset of dementia.