Association of Serum Uric Acid and Disease Duration With Frequent Gout Attacks: A Case-Control Study

Objective. To ascertain whether readily available disease and demographic factors associate with frequent acute attacks of gout, and to find out whether they can identify patients especially at risk of recurrent gout attacks. Methods. Data from 3 previous studies at Academic Rheumatology, University of Nottingham, UK, were used. Patients taking urate lowering treatment (ULT) were excluded, as it influences gout flare frequency. Logistic regression was used to examine the association between age, sex, body mass index (BMI), disease duration, cardiovascular comorbidities, tophi, serum uric acid (SUA), and >2 acute attacks of gout in the previous 12 months. Receiver operating curves were plotted to examine their ability in identifying patients with recurrent gout attacks. Results. A total of 468 gout patients (88.5% men, mean +/- SD age 62.2 +/- 11.3 years, BMI 29.8 +/- 5.0 kg/m(2)) were included. Disease duration and SUA associated independently with >2 acute attacks of gout in the previous 12 months (adjusted odds ratio 1.36 [95% confidence interval (95% CI) 1.08-1.72] and 1.27 [95% CI 1.10-1.46], respectively). However, these factors performed poorly in identifying patients with frequent gout attacks, with an area under the curve (AUC) of 0.61, and there was an insignificant increase in AUC on adding other variables (AUC 0.64). Conclusion. Higher SUA and longer disease duration associate independently with frequent gout attacks, presumably because of greater crystal load. This association supports early consideration of ULT for gout patients with higher SUA. However, as readily available disease and demographic factors perform poorly in identifying patients with frequent gout attacks, further research is required to ascertain the reasons underlying interpersonal variations in frequency of gout attacks.