Objective: To study the role of Trp64Arg polymorphism of the ADRB3 gene in the risk of developing hyperuricemia in 1051 subjects from southern Spain, with a followup of 6 years. The inclusion of plasma levels of uric acid as a diagnostic criterion to define the metabolic syndrome is under discussion. Genes responsible for insulin resistance could contribute to the development of hyperuricemia. Previous cross-sectional studies have suggested ADRB3 as a possible candidate gene in the development of hyperuricemia and insulin resistance.
Methods: A prospective, population-based, cohort study of 1051 persons examined in 1997-98 and reassessed at a second examination 6 years later. The metabolic phenotype was assessed at baseline and again at the followup. Insulin resistance was measured by homeostasis model assessment. The Trp64Arg polymorphism of ADRB3 was detected by real-time polymerase chain reaction. Subjects were considered normouricemic if their serum uric acid levels were <or=7 mg/dl for men or <or= 6 mg/dl for women.
Results: Carriers of the Arg64 allele who were normouricemic at baseline had a higher risk of developing hyperuricemia 6 years later (p = 0.017, OR 2.3, 95% CI 1.1-4.6). Multivariate logistic regression analysis showed that the OR of having hyperuricemia at the 6-year followup was significantly associated with the Arg64 allele, after adjusting for age, weight gain, baseline levels of triglycerides, serum uric acid, and insulin resistance (OR 3.1, 95% CI 1.3-7.1).
Conclusion: Trp64Arg polymorphism of the ADRB3 gene predicted the risk of developing hyperuricemia in this adult population.