Association Between Serum Uric Acid Level, Metabolic Syndrome and Insulin Resistance in Obese Patients: Can Uric Acid Be Considered a New Metabolic Marker?

Introduction: Hyperuricemia has been associated with several factors that contribute to metabolic syndrome (MS). Our aim was to determine the association between serum uric acid (UA) levels and MS, number of MS components and insulin resistance (IR) in obese patients. Methods: Retrospective study of obese patients followed in specific appointments at Hospital de Braga (Non surgical Treatment of Obesity project). We excluded patients under UA lowering medication, without UA measurements and/or with no information about MS diagnosis. Statistical analysis was performed using SPSSv22 (R) (significance defined as p<0.05). Results: Of 239 patients, 78.7% were female and 46.4% had MS. The mean age was 45.08 +/- 12.58 years and mean serum UA level 4.84 +/- 1.28 mg/dL. Males presented higher UA levels compared with females (5.99 +/- 1.31 vs 4.52 +/- 1.08 mg/dL, p<0.001), as well as patients with MS (versus without MS) (5.07 +/- 1.21 vs 4.64 +/- 1.31 mg/dL, p=0.009). Mean UA levels increased as the number of MS components increased (0: 4.4 +/- 1.21 vs 1: 4.41 +/- 1.18 vs 2: 4.83 +/- 1.4 vs 3: 4.98 +/- 1.31 vs >= 4: 5.22 +/- 1.05 mg/dL, p=0.024). In non-diabetic patients, higher UA levels correlated with higher HOMA-IR (r=0.194, p=0.01). Analysing by sex, results remained significant only in females. Discussion and Conclusion: In obese women, MS presence was associated with higher UA levels, which were significantly elevated as the number of MS components increased. Moreover, a positive correlation with HOMA-IR was found in non-diabetic obese women. This suggests UA as a possible new metabolic marker for MS and IR, at least in females.