Gout Risk During Tuberculosis Treatment Higher With Obesity, Chronic Kidney Disease, Hyperuricemia

Obesity, chronic kidney disease (CKD), and/or pretreatment hyperuricemia increase the risk for gout during tuberculosis (TB) treatment, according to research results published in the International Journal of Rheumatic Diseases.

Researchers sought to determine the clinical characteristics and the risk factors for gout attacks during TB treatment in a population of South Korean patients.

The study cohort included 49 patients (mean age, 67.7±13.2 years; 79.6% men) who developed gout during TB treatment; 24 were found to have a prior history of gout.

During the course of TB treatment, about half of the gout attacks occurred within the first 2 months of treatment initiation; mean time from treatment initiation to gout development was 4.13±4.49 months. More than 80% of the gout attacks involved lower extremity joints, specifically the first metatarsophalangeal (44.9%) and ankle joints (44.9%). Tuberculosis medications included isoniazid, rifampin, ethambutol, and pyrazinamide.

Results of the study indicated that compared with a control group, patients with gout showed significantly higher body mass indices (21.2±3.5 vs 23.1±2.9 kg/m²; P =.014) and were more likely to have dyslipidemia (2.7% vs 20.0%; P =.01). Patients with gout also showed higher pretreatment serum uric acid levels and lower renal function.

Investigators assessed the serum uric acid (SUA) level changes in 25 patients who experienced new gout attacks and 75 patients without gout attacks, while receiving TB treatment. Compared with baseline levels, SUA levels in all patients were significantly increased 2 and 6 months after TB treatment initiation (5.5±1.9 mg/dL vs 8.4±3.1 mg/dL [P <.001] and 6.5±2.5 mg/dL [P =.028], respectively). Pretreatment SUA levels were significantly higher in patients who subsequently experienced a gout attack compared with those in the control group. However, while there was no significant difference in SUA levels at 2 months between the groups, SUA levels at 6 months showed significant differences similar to SUA levels at baseline.

Results from the multivariate analysis indicated that higher body mass index (P =.013), CKD (P =.019), and pretreatment hyperuricemia (uric acid ≥6.8 mg/dL; P =.008) were associated with the development of a posttreatment gout attack.

Study limitations included a small number of patients with gout, the retrospective nature of the study, and the possibility that gout incidents may not have been recorded in the case that patients received treatment at another center.

“When initiating [TB] therapy in patients with [risk for obesity, CKD, and hyperuricemia], physicians should pay attention to the development of gout attacks and educate their patients,” the researchers concluded.

Reference

Ha Y-J, Chung SW, Lee JH, Kang EH, Lee YJ, Song YW. Clinical features and risk factors for gout attacks during anti-tuberculosis treatment: a case-control study in South Korea [published online September 17, 2019]. Int J Rheum Dis. doi:10.1111/1756-185X.13697