Risk of incident diabetes in patients with gout: a cohort study.

OBJECTIVE Patients with hyperuricemia or gout often have metabolic syndrome. Few prospective studies have examined the risk of incident diabetes mellitus (DM) in patients with gout, and there are no data to indicate whether the risk of DM in gout differs by sex. Therefore, this cohort study was undertaken to examine the overall and sex-specific incidence rates of DM in patients with gout. METHODS Using data from a US commercial insurance plan (2003-2012), the overall and sex-specific incidence rates of DM in patients with gout (ages ≥40 years) were compared to those in patients with osteoarthritis (OA). Incident DM was defined as a diagnosis of DM and at least one dispensing of an antidiabetic drug. The sex-specific effect of gout on DM risk was also examined. RESULTS The primary study cohorts consisted of 54,075 patients with gout and 162,225 patients with OA, matched for age, sex, and index date. In both cohorts, the mean age of the patients was 56.2 years, and 84.8% were men. Over a mean followup of 1.9 years, the incidence rate of DM was 1.91 per 100 person-years in patients with gout and 1.12 per 100 person-years in patients with OA. Multivariable Cox models adjusted for age, comorbidities, medications, and health care utilization factors revealed that gout was associated with an increased risk of DM (hazard ratio 1.45, 95% confidence interval [95% CI] 1.37-1.54) in both sexes. The impact of gout on the risk of incident DM was greater in women (hazard ratio 1.78, 95% CI 1.51-2.09) than in men (hazard ratio 1.41, 95% CI 1.33-1.50), with a significant interaction between gout and sex in relation to the risk of incident DM (P = 0.0009). CONCLUSION Gout was associated with an increased risk of developing DM compared to that in patients with OA after adjustment for potential confounders. In addition, the risk of incident DM associated with gout was higher among women than among men.