Cause of Hyperuricemia and the Relationship between Hyperuricemia and Obesity-Related Factors in Obese Children

The causes of hyperuricemia in obese children and the relationship between hyperuricemia and obesity-related factors were invesigated. Serum uric acid levels (UA) in obese children were significantly higher than those in control children, but urinary uric acid (U-UA), uric acid clearance (Cua) and FEUA (fractional excretion of uric acid: Cua/Ccr × 100) were lower in the obese children than in the controls. It is known that a high level of U-UA shows overproduction of uric acid in the body. The low U-UA in the obese children suggests that their hyperuricemia was not the result of overintake of food containing uric acid. There was a close correlation betweem UA and age/body weight and it became closer as they aged and gained weight. These results suggest that hyperuricemia in obese children is mainly attributable to impaired renal clearance of UA not to overproduction of it in the body and it will become higher according with age and body weight gain.