Background Genetic studies have associated the Glut9 renal transporter with hyperuricemia and gout. Insulin resistance has also been associated to hyperuricemia and gout due to a reduction of renal clearance of uric acid. A direct link between renal clearance of uric acid and insulin resistance is an attractive physiopathologic hypothesis.
Objectives To study whether there is a correlation between clearance of urate and insulin resistance in gout patients with normal renal function.
Methods Consecutive male patients with crystal-proven gout were evaluated if not on any drug with urate-lowering properties, show normal renal function (CKD 1 with no altered urine sediment), fasting glucose < 120 mg/dl, normal diet and alcohol avoidance. HOMA-IR was calculated with fasting glucose and insulin determinations. Inefficient excretion of uric acid being defined as clearance of uric acid < 6 ml/min/1.73 sqm. Hypertension, previous ethanol intake, body mass index, time from onset, age, vascular events, renal lithiasis, total cholesterol, HLD-cholesterol, LDL-cholesterol, triglycerides, glycosilated hemoglobin, number of flares, and presence of tophi were also recorded in the database.
Results One hundred and twenty-nine male patients were included for analysis. Age was 53 years (28-60), time from onset 5.5 (3-11) years. Previous ethanol intake > 15 g/day, hypertension, glycosilated hemoglobin, clearance of creatinine, and HOMA-IR were associated to clearance of uric acid in bivariate regression analysis. Multivariate regression analysis showed that HOMA-IR and hypertension were the only variables predictive of the model. HOMA-IR showed a R2 0.27. ROC area was 0.869 and a HOMA-IR cut-off >2.7 showed 80% sensitivity ad 81% specificity.
Conclusions Insulin resistance, but also hypertension, was associated with lower clearance of uric acid in a series of phenotype-selected male gout patients, showing a plausible link between glucose metabolism and sugar transporters of uric acid that deserves further investigation.
Disclosure of Interest F. Perez-Ruiz Consultant for: Ardea, Savient, Menarini, Astra, Metabolex, Pfizer, Novartis, SOBI, Speakers bureau: Menarini