Comorbidity among inpatients with dementia: a preliminary cross-sectional study in West China

OBJECTIVE: To investigate comorbidities among hospitalized patients with dementia. METHOD: Data were extracted from the discharge records in our hospital. Comorbidities based on ICD-10 were selected from the Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI). The distributions of these comorbidities were described in dementia inpatients and age- and sex-matched nondementia controls, as well as in inpatients with Alzheimer’s disease and vascular dementia. A logistic regression model was applied to identify dementia-specific morbid conditions. RESULTS: A total of 3355 patients with dementia were included, with a majority of 1503 (44.8%) having Alzheimer's disease, 395 (11.8%) with vascular dementia, and 441 (13.1%) with mixed dementia. The mean number of comorbidities was 3.8 in dementia patients (vs. 2.9 in controls). The most prevalent comorbidities in inpatients with dementia compared with those without dementia were cerebral vascular disease (73.0% vs. 35.9%), hypertension (62.8% vs. 56.2%), and peripheral vascular disease (53.7% vs. 31.2%). Comorbidities associated with dementia included epilepsy (OR 4.8, 95% CI 3.5–6.8), cerebral vascular disease (OR 4.1, 95% CI 3.7–4.5), depression (OR 4.0, 95% CI 3.2–5.0), uncomplicated diabetes (OR 1.5, 95% CI 1.4–1.7), peripheral vascular disease (OR 1.8, 95% CI 1.6–2.0), rheumatoid arthritis collagen vascular disease (OR 1.7, 95% CI 1.3–2.3), and anemia (OR 1.2, 95% CI 1.04–1.3). Some comorbidities suggested a protective effect against dementia. They were hypertension (OR 0.8, 95% CI 0.7–0.9), COPD (OR 0.6, 95% CI 0.5–0.6), and solid tumor without metastasis (OR 0.4, 95% CI 0.3–0.4). Vascular dementia has more cardiovascular and cerebrovascular comorbidities than Alzheimer's disease. CONCLUSION: Patients with dementia coexisted with more comorbidities than those without dementia. Comorbidities (esp. cardio-cerebral vascular risks) in patients with vascular dementia were more than those in patients with AD. Specifically, vascular and circulatory diseases, epilepsy, diabetes and depression increased the risk of dementia. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40520-023-02349-3.