Association of single measurement of estimated glomerular filtration rate and non-quantitative dipstick proteinuria with all-cause and cardiovascular mortality in the elderly. Results from the Progetto Veneto Anziani (Pro.V.A.) Study

To explore the independent and combined clinical validity of estimated glomerular filtration rate (eGFR) and proteinuria on predicting all-cause and cardiovascular mortality in an Italian elderly population. Baseline eGFR and proteinuria, all-cause and cardiovascular mortality during a mean follow-up time of 4.4 years were evaluated in 3063 subjects aged 65 years and older of the Progetto Veneto Anziani (Pro.V.A.) Study. Subjects with eGFR<60ml/min/1.73m(2) (n=956) presented a higher prevalence of proteinuria in comparison with those with eGFR≥60ml/min/1.73m(2) (33.8% vs 25.1%, p<0.01). After multivariable adjustment including proteinuria and major diseases, eGFR<60ml/min/1.73m(2) was not associated with increased all-cause mortality. After multivariable adjustment including eGFR and major diseases, proteinuria was associated with all-cause mortality in overall subjects (HR=1.43, 95% CI 1.15-1.78, p<0.01), and in both sexes. After multivariable adjustment both eGFR<60ml/min/1.73m(2) (HR=1.68, 95% CI 1.02-2.78, p=0.04), and proteinuria (HR=2.07, 95% CI 1.31-3.27, p<0.01) were associated with increased cardiovascular mortality. Subjects with both impaired eGFR and presence of proteinuria showed a higher risk for both all-cause and cardiovascular mortality compared to those with normal eGFR and absence of proteinuria. In this general Italian elderly population proteinuria is an independent predictor of all-cause and cardiovascular mortality, while eGFR is not an independent predictor of all-cause mortality, and it is nominally significantly associated with cardiovascular mortality. However, mortality risk is higher in individuals with combined reduced eGFR and proteinuria.