Risk of dementia among patients with Sjogren's syndrome: A nationwide population-based cohort study in Taiwan.

OBJECTIVE:Autoimmunity may play a role in early-stage dementia. The association between Sjogren's syndrome (SS) and dementia remains unknown. This study was conducted to provide epidemiologic evidence for this relationship. METHODS:This 12-year, nationwide, population-based, retrospective cohort study analyzed the risk of dementia in the SS cohort. We also investigated the incidence of dementia among patients with SS by using data from the Longitudinal Health Insurance Database 2000, maintained by the Taiwan National Health Research Institutes. To balance the prevalence of characteristics in the cohorts, we used the propensity score to match selected comorbidities in the two cohorts. We also analyzed the association between SS and dementia among patients with different potential risks by using a Cox proportional hazard model. RESULTS:According to the analysis of data obtained from follow-up conducted during 2000-2012, the incidence of dementia in the SS cohort was 1.21-fold that in the control cohort (95% confidence interval [CI] = 1.02-1.45, p < 0.05). In the group older than 65years, the incidence of dementia was significantly high (adjusted hazard ratio [aHR] = 5.30, 95% CI = 4.26-6.60, p < 0.01). After adjustment for comorbidities, including Parkinson's disease (aHR = 2.98, 95% CI = 1.80-4.94), insomnia (aHR = 1.45, 95% CI = 1.14-1.85), and hypertension (aHR = 1.43, 95% CI = 1.19-1.71), the association between SS and dementia was still significant. CONCLUSION:This 13-year, nationwide, population-based retrospective cohort study revealed patients with SS to have a higher risk of dementia.