Cardiovascular and metabolic comorbidities in patients with Alzheimer's disease and vascular dementia compared to a psychiatric control cohort.

BACKGROUND: Multimorbidity in dementia is associated with an increased risk of complications and a higher need for care. Having knowledge of cardiovascular and metabolic comorbidities is crucial when making decisions about diagnostic procedures and therapies. We compared the prevalence of comorbidities in hospitalized patients with Alzheimer's disease (AD), vascular dementia, and psychiatric diseases other than dementia. Additionally, we compared clinically relevant health-care indicators (length of hospital stay, rate of re-hospitalization) between these groups.

METHODS: We used information from a database of treatment-relevant indicators from psychiatric and psychosomatic hospitals throughout Germany. This database contains routinely recorded data collected from 85 German hospitals from 2011 to 2015. In total, 14 411 AD cases, 7156 vascular dementia cases, and 34 534 cases involving non-demented psychiatric patients (used as controls) were included. To analyze comorbidities and health-care indicators, χ2 tests and t-tests were used.

RESULTS: Diabetes mellitus, lipoprotein disorders, coronary artery diseases, cardiac arrhythmia and insufficiency, and atherosclerosis were significantly more prevalent in patients with vascular dementia than in those with AD and psychiatric controls. Hypertension and coronary artery diseases were less frequently associated with AD than with non-demented psychiatric controls (P < 0.001). Additionally, dementia patients with cardiovascular or metabolic diseases exhibited longer hospital stays (+ 1.4 days, P < 0.001) and were more often re-hospitalized within 3 weeks (P < 0.001) and 1 year (P < 0.001) compared to dementia patients without these comorbidities.

CONCLUSIONS: Awareness of somatic comorbidities in patients with dementia is crucial to avoid complications during inpatient treatment. The occurrence of comorbid disorders was associated with longer and more frequent hospital stays, which potentially lead to higher health-care costs. Further studies should evaluate the causative association between somatic comorbidities and inpatient costs in dementia patients.