Comorbidity patterns differ in years preceding early-onset Alzheimer's diagnosis

A population-based case–control study in Alzheimer's & Dementia examined comorbidities and health-care use during the 15 years preceding early-onset Alzheimer's disease (EOAD) diagnosis. Researchers included 407 patients diagnosed at two Finnish university hospitals during 2010–2021 and 4,035 age- and sex-matched controls, using nationwide registers to identify prior diagnoses and health-care visits.

During the 1–5 years before diagnosis, patients with EOAD more frequently had vertigo (5.9% vs. 2.1%), depression (5.7% vs. 2.3%), headache (4.9% vs. 1.6%) and delirium (1.5% vs. 0.1%); all comparisons had p < 0.001. Brain injuries, thyroid disorders, alcohol-related disorders, epilepsy, strokes and otorhinolaryngologic diseases were also more prevalent. Only otorhinolaryngologic diseases differed 6–10 years before diagnosis (4.7% vs. 2.1%; p = 0.036), and no differences were observed 11–15 years before diagnosis. Hypertension and dyslipidemia did not differ between groups. Health-care use increased markedly from the year before EOAD diagnosis.

These findings suggest that morbidity and health-care use patterns may offer clues to earlier recognition. However, the observational design cannot establish causation or whether these patterns reliably identify individuals who will develop EOAD. The supplied abstract does not report predictive performance or the magnitude of increased health-care use; full text was unavailable for assessment.