ABCG2 and Hypertension: The variability in the serum UA concentrations was best explained by sex; age; BMI; hypertension; hyperglycemia; the serum levels of triacylglycerols, creatinine and GGT; allopurinol intake, MTHFR c.1286A>C, ABCG2 c.421C>A, SLC2A9 c.844G>A and SLC2A9 c.881G>A.