Hyperuricemia as a potential risk factor for type 2 diabetes and diabetic nephropathy.

Correspondence to: Richard J Johnson. University of Colorado Anschutz Medical. Campus, Aurora, CO, 80045, USA. E-mail: richard.johnson@ ucdenver.edu Serum uric acid has recently received attention as a potential biomarker independently predicting the development of hypertension, diabetes mellitus, and chronic kidney disease.1-3 Elevated serum uric acid has also been reported to predict development of nephropathy in type 1 diabetes.4-7 Less is known, however, about the role of serum uric acid in predicting nephropathy in type 2 diabetes. In this issue of the Brazilian Journal of Nephrology, Fouad et al.8 performed a case-control study in Egyptian adults with and without type 2 diabetes that were matched for age, sex and body mass index (BMI). The study included 986 participants; 250 non-diabetic controls, 352 with type 2 diabetes for less than 5-years and 384 with type 2 diabetes for more than 5-years. The participants of the three groups were similarly obese with mean BMI between 30 and 32 kg/m2. The most important observation was that serum uric acid showed a stepwise increase between groups, and overall 32% of subjects with type 2 diabetes demonstrated hyperuricemia (defined as serum uric acid > 7.0 mg/dl). Furthermore, the increase in serum uric acid correlated with worsening hypertension, albuminuria and kidney function. The paper is interesting for several reasons. First, some studies of diabetes mellitus have reported serum uric acid to be lower than what is observed in nondiabetic subjects, and this has been attributed to elevated GFR (hyperfiltration) and poor glycemic control (elevated HbA1c).9,10 Bo et al.11, however, noted that subjects with Hyperuricemia as a potential risk factor for type 2 diabetes and diabetic nephropathy