Chen KT, et al. - The link between rheumatic diseases and dementia was explored in this investigation. Among study participants, patients with rheumatoid arthritis, Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), psoriatic arthritis (PsA) and osteoarthritis (OA) were found to be significantly associated with a higher risk of dementia, compared with those without rheumatic diseases. Inflammation and medications were presumed to be 2 possible mechanisms.

Methods

• Using the Taiwan National Health Insurance Research Database, researchers extracted data for this case-control study.
• Diagnosis of dementia and rheumatic diseases were retrieved by the International Classification of Diseases-9 code.
• Researchers recruited cases (n = 10 180) with dementia and controls (n = 61 080) during 2000–2010, by matching on age, gender and index date with a match ratio 1 : 6.
• They used Chi-square test to estimate the baseline features of the cases and controls for categorical variables such as age and gender.
• They also used simple conditional and multivariable conditional logistic regression models to estimate crude and adjusted odds ratios.

Results

• Researchers observed statistical significance in Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), and osteoarthritis (OA) among females (P < 0.05 for SS and SLE; P < 0.01 for OA), and in SS, psoriatic arthritis (PsA) and OA among males (P < 0.01 for SS; P < 0.05 for PsA and OA).
• Among the younger group (age = 40–64), they observed a significant difference in SLE and OA (P < 0.01 for SLE and OA), and in the older group (age ≧ 65), in SS and OA (P < 0.01 for SS and OA).