Uric acid and risk of new-onset metabolic syndrome, impaired fasting glucose and diabetes mellitus in a general Italian population: data from the Pressioni Arteriose Monitorate E Loro Associazioni study.

BACKGROUND: Although several data suggest that serum uric acid (SUA) predicts future development of metabolic abnormalities, the evidence is not conclusive in Mediterranean populations.
METHODS: A total of 3200 individuals were randomly selected from the residents of Monza (North Italy) to be representative of its general population for sex and age (25-74 years). The participation rate was 64%. At baseline and 10 years later, we measured waist circumference, office blood pressure, fasting blood glucose, serum triglycerides, serum HDL cholesterol and SUA.
RESULTS: The analysis was carried out in individuals without metabolic syndrome at baseline (N = 1192) when looking for incidence of metabolic syndrome, without impaired fasting glucose (IFG) at baseline (N = 1320) when looking for incidence of IFG and without diabetes mellitus at baseline (N = 1352) when looking for incidence of diabetes mellitus. Adjusting for confounders, a 1-SD increase of baseline SUA was not associated with and increased risk of new-onset metabolic syndrome, but with new-onset IFG [relative risk (RR) = 1.26, confidence interval (CI) 1.06-1.5, P = 0.01]. It was associated with a 29% increased risk of new-onset diabetes mellitus, that was more than twice in the highest as compared with the lowest quartile of baseline SUA (RR = 1.29, CI 0.98-1.7, P = 0.07, and RR = 2.16, CI 0.95-4.88, P = 0.07). Focusing the analysis on the individuals with age above the median value, SUA increase was significantly associated with an increased risk of new-onset metabolic syndrome, IFG and diabetes mellitus.
CONCLUSION: SUA increase is associated with an increased risk of developing IFG and, in the population fraction with age above the median value, also metabolic syndrome and diabetes mellitus.