Uric acid level changes after bariatric surgery in obese subjects with type 2 diabetes mellitus

Background: The purpose of the study was to investigate the incidence of hyperuricemia (HU) in obese subjects with type 2 diabetes mellitus (T2DM) before and after Roux-en-Y gastric bypass (RYGB), to describe the impact of this therapy in reducing uric acid levels, and its possible mechanism. This study was performed by cooperation with the First affiliated hospital of Soochow University and the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, department of general surgery.

Methods: A retrospective study was performed. From February 2015 to December 2017, we evaluated 147 obese patients with T2DM. Blood samples and other clinical data were drawn before and postoperative (1, 3, 6, 12 months after RYGB). All obese patients with T2DM underwent laparoscopic Roux-en-Y gastric bypass surgery (LRYGB). Different gender with HU were compared before and after surgery.

Results: A total of 147 patients received LRYGB (75 were female, 72 were male), and 48 patients with HU (22 were female, 26 were male). Four women and 2 men were lost to follow-up, they were excepted from this study. No patients with HU lost to follow-up. There's an intuitive downward trend about uric acid levels both in men and women, with men from 497.9 µmol/L before surgery to 371.5 µmol/L 1 year after surgery, P=0.000; women from 432.3 to 354.1 µmol/L, P=0.002. The proportion of HU changed with men from 37.1% (26/70) before surgery to 12.9% (9/70) one year after surgery, women from 31.0% (22/71) to 14.1% (10/71). The results of binary logistic regression analysis confirmed that triglycerides were clinical predictors for HU remission (P=0.004). No major late surgical complications were reported.

Conclusions: Our data showed that, bariatric surgery was effective to decrease the levels of serum uric acid (SUA) in obese patients with T2DM. Compared with traditional drug treatment, this shows a possible treatment of HU by RYGB. The remission of HU was associated with the decreased triglyceride levels in obese patients with T2DM, independent of BMI. The potential role of triglycerides in the remission of HU merits further study.