Uric acid as a predictor of endothelial dysfunction in patients with metabolic syndrome

ABSTRACT Objective: We conducted a study to examine the association of endothelial dysfunction and oxidative stress with uric acid levels in patients of metabolic syndrome. Subjects and methods: One hundred and two patients of Metabolic Syndrome (International Diabetes Federation definition) were included in the study. Anthropometric measurements, serum uric acid levels, fasting blood sugar levels and lipid levels, as well as malondialdehyde and reactive nitrogen intermediates were measured after an 8-hour fasting period. Flow mediated vasodilation (FMD) of the brachial artery was measured and endothelial dysfunction was defined as an increase in diameter < 10% post compression. Results: A total of 102 patients were included in the study. Mean uric acid level was 5.49 ± 1.61 mg%. A total of 59 patients in the study had endothelial dysfunction, defined by an abnormal FMD. Patients with an abnormal FMD had higher levels of serum uric acid which was statistically significant (p value = 0.010). Serum RNI and MDA levels were negatively correlated with uric acid, but did not reach statistical significance. Patients with an abnormal FMD had a lower RNI level, but this did not reach statistical significance. Serum MDA levels were significantly higher in patients with an abnormal FMD (p value = 0.038). Conclusions: Uric acid was significantly associated with endothelial dysfunction in patients with metabolic syndrome in our study. It was inversely correlated with serum RNI and MDA levels, but this did not reach statistical significance.

Antioxidant status in children with homozygous thalassemia.

The status of enzymatic and non-enzymatic anti-oxidants was evaluated in 41 patients with transfusion dependent beta-thalassemia. An additional 20 age-matched children, with non-hemolytic anemia, served as controls. Fresh blood samples, obtained in the morning, were processed immediately. Plasma was stored at -80 degrees C. Levels of vitamins A and E were assayed simultaneously by HPLC. RBC vitamin A was not measurable in 29 (70.7%) thalassemics and in all the controls. Plasma vitamin A levels were lower in thalassemics than in controls (p<0.05). Vitamin E in RBCs was not measurable in 13 (31. 7%) cases. The mean level of RBC vitamin E was 3 times lower in thalassemics. Similarly, SOD enzyme activity in thalassemics, was at least 1.5 lower in comparison to the activity documented in controls (p<0. 05). The observations indicate that thalassemics have enhanced oxidative stress. Administration of selective antioxidants and a balanced diet may preclude oxidative damage.