Risk of cognitive disorders in patients with primary Sjögren's disease: data from Korean Health Insurance Service.

OBJECTIVE: To investigate the risk of incident cognitive disorders in patients with primary Sjögren's disease (pSjD) using nationwide Korean National Health Insurance Service data. METHODS: This retrospective cohort study included patients newly diagnosed with pSjD between 2010 and 2021 and propensity score-matched controls. The primary outcome was a composite of Alzheimer's dementia (AD), vascular dementia (VaD), secondary dementia, unclassified dementia and mild cognitive impairment (MCI). Adjusted HRs (aHRs) and 95% CIs were estimated using multivariable Cox regression. Age-stratified analyses were also performed. RESULTS: A total of 12 731 patients with pSjD and 36 514 matched controls were analysed. pSjD was associated with increased risks of total cognitive disorders (aHR 1.48, 95% CI 1.36 to 1.63), AD (aHR 1.48, 95% CI 1.35 to 1.63), secondary dementia (aHR 2.24, 95% CI 1.45 to 3.48), unclassified dementia (aHR 1.43, 95% CI 1.21 to 1.70) and MCI (aHR 1.62, 95% CI 1.41 to 1.85). In age-stratified analyses, pSjD was associated with an increased risk of MCI among participants aged <65 years (aHR 1.46, 95% CI 1.06 to 2.01). Among those aged 65-74 years, pSjD was associated with increased risks of total cognitive disorders, AD and MCI. CONCLUSIONS: pSjD was associated with increased risks of multiple cognitive disorders. The age-specific patterns-an increased risk of MCI among individuals aged <65 years and increased risks of total cognitive disorders, AD and MCI among those aged 65-74 years-underscore the need for clinical attention to cognitive symptoms across age groups in patients with pSjD.