Hearing Loss is Associated With Risk of Alzheimer's Disease: A Case-Control Study in Older People

Background: It remains unknown whether hearing loss increases the risk of Alzheimer's disease. This study aimed to examine the association between hearing loss and risk of Alzheimer's disease in older people in Taiwan. Methods: Analyzing the database from Taiwan's National Health Insurance Program, this case-control study enrolled 488 subjects >= 65 years old with newly diagnosed Alzheimer's disease as a case group and 1952 subjects without Alzheimer's disease as a control group from 1998-2011. Patients with Alzheimer's disease and other comorbidities were identified by analyzing ICD-9 coding in claims data. The association of hearing loss, other comorbidities, and risk of Alzheimer's disease were compared between groups. Results: After controlling for confounders, multivariable logistic regression showed an adjusted odds ratio of Alzheimer's disease of 1.39 in people with hearing loss (95% CI, 1.05-1.84) versus those without. Parkinson's disease (OR 4.44; 95% CI, 2.54-7.78), head injury (OR 2.31; 95% CI, 1.46-3.66), depression (OR 1.68; 95% CI, 1.19-2.39), hypertension (OR 1.40; 95% CI, 1.10-1.79), and age (each year, OR 1.03; 95% CI, 1.01-1.05) also showed strong links with Alzheimer's. Conclusions: Hearing loss is associated with increased risk of Alzheimer's disease in older people in Taiwan.