The association between thyroid disorders and incident gout: population-based case-control study.

Context: Thyroid hormones influence kidney function and thereby might alter serum urate levels, a major risk factor for gouty arthritis.

Objective: To assess the risk of developing incident gout in association with hypothyroidism or hyperthyroidism.

Design: Retrospective population-based case-control analysis.

Setting: UK-based Clinical Practice Research Datalink, a primary care research database.

Patients: We identified adult patients with a diagnosis of incident gout between 1990 and 2014. We matched one control to each gout case in terms of age, sex, general practice, calendar time, and years of active history in the database.

Main Outcome Measure: We used conditional logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for developing gout in association with hypo- or hyperthyroidism and adjusted for potential confounders.

Results: The study population encompassed 68,159 incident gout cases, of whom 78.8% were male, and the same number of matched controls. There was no increased risk of gout in patients with hypothyroidism: adjusted OR of gout of 1.12 (95% CI 1.05-1.20) compared with no hypothyroidism. Current short-term treatment of thyroid hormone replacement therapy was associated with an adjusted OR of gout of 1.54 (95% CI 1.24-1.92), compared with no treatment. Neither hyperthyroidism nor current treatment with thyroid suppression therapy was associated with gout (adjusted OR, 1.08 [95% CI 0.95-1.22] and 0.82 [95% CI 0.57-1.17], respectively).

Conclusion: This large observational study does not provide evidence that hypothyroidism or hyperthyroidism, irrespective of treatment, is associated with a clinically relevant increased risk of developing incident gout. There may be an exception among patients with newly diagnosed and treated hypothyroidism.