The association of uric acid with mortality modifies at old age: data from the uric acid right for heart health (URRAH) study
Andrea Ungar, Giulia Rivasi, Mauro Di Bari, Agostino Virdis, Edoardo Casiglia, Stefano Masi, Alessandro Mengozzi, Carlo M. Barbagallo, Michele Bombelli, Bernardino Bruno, Arrigo F.G. Cicero, Massimo Círillo, Pietro Cirillo, Giovambattista Desideri, Lanfranco D’Elia, Claudio Ferri, Ferruccio Galletti, Loreto Gesualdo, Cristina Giannattasio, Guido Iaccarino, Michele Ciccarelli, Luciano Lippa, Francesca Mallamaci, Alessandro Maloberti, Alberto Mazza, María Lorenza Muiesan, Pietro Nazzaro, Paolo Palatini, Gianfranco Parati, Roberto Pontremoli, Fosca Quarti‐Trevano, Marcello Rattazzi, Massimo Salvetti, Valérie Tikhonoff, Giuliano Tocci, Rosario Cianci, Paolo Verdecchia, Francesca Viazzi, Massimo Volpe, Guıdo Grassı, Claudio Borghi
Abstract
OBJECTIVES: In older individuals, the role of serum uric acid (SUA) as risk factor for mortality is debated. This study investigated the association of SUA with all-cause and cardiovascular (CV) mortality in older adults participating in the large multicentre observational uric acid right for heart health (URRAH) study. METHODS: Eight thousand URRAH participants aged 65+ were included in the analysis. The predictive role of SUA was assessed using Cox regression models stratified according to the cut-off age of 75. SUA was tested as continuous and categorical variable (age-specific quartiles). The prognostic threshold of SUA for mortality was analysed using receiver operating characteristic curves. RESULTS: Among participants aged 65-74, multivariate Cox regression analysis adjusted for CV risk factors and comorbidities identified an independent association of SUA with both all-cause mortality (hazard ratio [HR] 1.169, 95% confidence interval [CI] 1.107-1.235) and CV mortality (HR 1.146, 95% CI 1.064-1.235). The cut-off value of 4.8 mg/dl discriminated mortality status. In participants aged 75+, we observed a J-shaped relationship of SUA with all-cause and CV mortality, with risk increasing at extreme SUA levels. CONCLUSIONS: These results confirmed the predictive role of SUA for all-cause and CV mortality in older adults, while revealing considerable age-related differences. Mortality risk increased at higher SUA levels in participants aged 65-74, with a prognostic threshold of 4.8 mg/dl. The relationship between SUA and mortality was J-shaped in oldest participants. Large interventional studies are needed to clarify the benefits and possible risks of urate-lowering treatments in older adults.