(HealthDay News) — Circulating uric acid affects non-enzymatic antioxidant capacity (NEAC) and markers of oxidative stress in obese subjects, according to a study published online December 18 in Diabetes.
Elisa Fabbrini, MD, PhD, from the Washington University School of Medicine in St. Louis, and colleagues assessed whether alterations in circulating uric acid affect systemic NEAC, markers of systemic and muscle oxidative stress, and whole-body insulin sensitivity using data from obese subjects with high (15 subjects) or normal (16 subjects) serum uric acid. Thirteen of the subjects with high uric acid underwent reduction of serum uric acid to zero by infusion of recombinant urate oxidase and were studied again.
The researchers found that, compared to those with normal uric acid, individuals with high uric acid had 20 to 90% increased NEAC, 40% lower insulin sensitivity, and 30%lower levels of markers of oxidative stress (all P<0.05). Reduction of uric acid resulted in a decrease of 45 to 95% in NEAC and increases of 25–40% in systemic and muscle markers of oxidative stress (all P<0.05), but the reduction had no impact on insulin sensitivity.
“These results demonstrate that circulating uric acid is a major antioxidant, and might help protect against free-radical oxidative damage,” the authors write. “However, oxidative stress is not a major determinant of insulin action in vivo.”
The study was partially funded by a grant from Sanofi-Aventis.