Co-morbidity associated with dementia.

PURPOSE: The purpose of this study was to identify common co-morbid conditions associated with dementia subtypes and to evaluate the association of hypertension, diabetes mellitus, atrial fibrillation, congestive heart failure, and anemia with dementia subtypes relative to controls.
METHODS: Hospital discharge data were used to identify 15,013 subjects from South Carolina with a diagnosis of dementia between 1998 and 1999. A control group of 15,013 persons without dementia was randomly sampled from hospital discharge records and matched to persons with dementia on the basis of age, race, and gender. Multiple hospitalizations for each patient were merged, and repeated diagnoses during separate hospitalizations were counted once.
RESULTS: After adjusting for age, race, and gender, persons with Alzheimer's disease and dementia associated with medical conditions were less likely to be diagnosed with hypertension, diabetes, congestive heart failure, and atrial fibrillation than were controls. Patients with multi-infarct dementia were also less likely to have congestive heart failure, but were more likely to have diabetes. Anemia was not associated with any dementia subtype.
CONCLUSIONS: There are distinct differences in comorbid conditions among dementia subtypes. Our research does not support previous studies that suggest a circulatory component to the development of Alzheimer's disease.