RESUMEN
BACKGROUND: Protein intake is considered a determinant of glomerular filtration rate (GFR). Urinary urea is an objective marker of protein intake. The population-based study investigated, cross-sectionally and longitudinally, the association of protein intake with GFR, indexed by estimated GFR (eGFR). METHODS: Data were collected on overnight urinary urea, serum creatinine (S-cr), eGFR and other variables in 1522 men and women aged 45-64 years who participated in the Gubbio study (baseline). S-Cr, eGFR and other variables were re-assessed in 1144 of the 1425 survivors after 12-year follow-up. RESULTS: At baseline, mean ± SD was 84.0 ± 11.4 mL/min × 1.73 m(2) for eGFR calculated by CKD-Epi equation and 1.34 ± 0.57 g/day per kg of ideal weight for protein intake assessed by measurements of overnight urine excretion of urea nitrogen. Cross-sectional analyses of baseline data indicated a positive correlation of protein intake with eGFR (R = 0.180, P < 0.001). In multi-variable regression, 1 g/day higher protein intake related to 4.7 mL/min × 1.73 m(2) higher eGFR [95% confidence interval (CI) = 3.7/5.7]. At follow-up, mean ± SD of 12-year eGFR change was -11.6 ± 9.0 mL/min × 1.73 m(2). Baseline protein intake correlated with more negative eGFR change (R = -0.251, P < 0.001). In multi-variable regression, 1 g/day higher protein intake related to -4.1 mL/min × 1.73 m(2) more negative eGFR change (95% CI = -5.1/-3.1) and to 1.78 risk for incidence of eGFR < 60 mL/min × 1.73 m(2) (95% CI = 1.15/2.78). CONCLUSIONS: In middle-aged adults, high protein intake is associated cross-sectionally with higher GFR but longitudinally with greater GFR decline over time.
Asunto(s)
Proteínas en la Dieta/administración & dosificación , Tasa de Filtración Glomerular/fisiología , Riñón/fisiología , Urea/orina , Índice de Masa Corporal , Estudios Transversales , Femenino , Humanos , Pruebas de Función Renal , Estudios Longitudinales , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVES: Serum uric acid (SUA) and estimated glomerular filtration rate (eGFR) were separately assessed as risk factors for incident coronary hard (CHDH), cardiovascular disease (CVDH) or all-cause (ALL) deaths but never concomitantly in a residential cohort. MATERIAL AND METHODS: Men and women aged 35-74years, totaling 2888 subjects were followed 13.5-19.5years for incident CVDH, CHDH and ALL deaths. Systematic comparisons among different end-points were based on: age, gender, systolic blood pressure (SBP), total and HDL cholesterol, cigarette consumption, body mass index, blood glucose, SUA, eGFR from the Chronic Kidney Disease Prognosis Consortium (eGFR_CKDEPI) and (eGFR_CKDEPI)(2). RESULTS: Significant (p<0.00001) differences in SUA quintiles were seen for SBP, total and HDL cholesterol, body mass index and eGFR_CKDEPI whereas cigarettes and blood glucose were not statistically different. There were increasingly larger proportions of all events in SUA quintiles (0.05>p<0.0001). Among 4 major continuous variables, SUA was largely accurate (ROC>0.610) to predict all end-points whereas eGFR_CKDEPI was the worse univariate predictor. Multivariately, age, gender, SBP and cigarettes were significant predictors for all end-points. Total cholesterol was a significant predictor only for CHDH events. Blood glucose and SUA were contributors for CVDH events (RR, for 1mg/dl of SUA, 1.09, 95%CI 1.01-1.17), CVD deaths (RR 1.11, 95%CI 1.03-1.20) and ALL deaths (RR 1.08, 95%CI 1.03-1.14) whereas (eGFR_CKDEPI)(2) was for ALL deaths only (RR 1.02, 95%CI 1.00-1.04). CONCLUSION: SUA is a predictor of long-term incidence of cardiovascular events and deaths and all-cause mortality and should be considered for risk predictive purposes and instruments whereas eGFR_CKDEPI only predicts all-cause mortality by a U-shaped relation.