Long-term increase in serum uric acid and its predictors over a 25 year follow-up: Results of the PAMELA study

Background and aims: Hyperuricemia (HU) has been shown to be associated with an adverse impact on cardiovascular and metabolic risk. Scanty data are available in the general population on the longitudinal changes in serum uric acid (SUA), the occurrence of HU and their potential predictors. We examined during a 25-year follow-up the SUA changes and the factors associated with HU development in the Pressioni Arteriose Monitorate E loro Associazioni (PAMELA) study. Methods and results: We analyzed data collected in 561 subjects of the PAMELA study evaluated during an average follow-up time amounting to 25.4 ± 1.0 years (mean ± SD). HU was defined by the Uric Acid Right for Heart Health (URRAh) cutoff (5.1 for females and 5.6 mg/dl for males). Mean SUA values during follow-up increased from 4.7 ± 1.1 to 5.0 ± 1.2 mg/dl (P<0.001), the average SUA elevation amounting to of 0.3 ± 1.1 mg/dl 26.7 % of the subjects displayed HU at the follow-up. This was associated at the multivariable analysis with female gender, office, home and 24-h blood pressure, diuretic treatment, serum triglycerides and baseline SUA, as well as the increase in waist circumference and the reduction in renal function. Conclusion: The present study provides longitudinal evidence that in the general population during a 25 year follow-up there is a progressive increase in SUA and HU development. Baseline SUA represents the most important factor associated with these modifications. Gender, renal dysfunction, triglycerides, obesity, diuretic treatment and blood pressure represent other variables capable to predict future occurrence of HU.