Hyperuricemia and dementia - a case-control study.

BACKGROUND: There is evidence that uric acid may have antioxidant and neuroprotective effects and might therefore alter the risk for neurodegenerative diseases such as dementia. So far, the relation between serum uric acid (SUA) levels or hyperuricemia and dementia remains elusive. Most studies focused on the disease or SUA levels. Effects of anti-hyperuricemic treatment have not been considered yet. This study investigated the association between hyperuricemia and dementia taking into account anti-hyperuricemic treatment. METHODS: We used longitudinal German public health insurance data and analyzed the association between hyperuricemia with and without different treatment options and dementia in a case-control design. Applying logistic regression the analysis was adjusted for several potential confounders including various comorbidities and polypharmacy. RESULTS: We identified 27,528 cases and 110,112 matched controls of which 22% had a diagnosis of hyperuricemia or gout and 17% received anti-hyperuricemic drugs. For patients with a diagnosis of hyperuricemia we found a slightly reduced risk for dementia (adjusted odds ratio [OR] 0.94, 95% confidence interval [CI] 0.89 to 0.98). The risk reduction was more pronounced for patients treated with anti-hyperuricemic drugs (adjusted OR 0.89, 95% CI 0.85 to 0.94, for regular treatment). CONCLUSIONS: Our results showed a slight reduction for dementia risk in patients with hyperuricemia, both with and without anti-hyperuricemic treatment.