Resumen de Hyperuricemia is associated with progression of chronic kidney disease in patients with reduced functioning kidney mass

Isabel Galán, Maria Angeles Goicoechea Diezhandino, Borja Quiroga Gili, Nicolás Macías Hernández, Alba Santos García, Soledad García de Vinuesa, Úrsula Verdalles Guzmán, Santiago Cedeño Mora, Eduardo Verde Moreno, A. Pérez de José, Ana García León, José Luño Fernández

• español

  Background and objectives: Hyperuricemia plays a major role in the development and progression of chronic kidney disease (CKD). Many large observational studies have indicated that increased serum uric acid level predicts the development and progression of CKD in some population, however this hypothesis has not been yet studied in patients with reduced renal mass.

  Design, setting, participants, & measurements: Retrospective study with a cohort of 324 patients with reduced renal mass from an outpatient basis, followed during 60 (36–98) months. Demographics variables, cardiovascular factors, concomitant medications, albuminuria and uric acid levels were recorded yearly. The primary endpoint was the annual fall of estimated glomerular filtration rate (eGFR) by MDRD-4. The sample was divided into three successive groups (A1: patients with fall of eGFR lower than median, A2: greater than median, B: without fall of eGFR). Factors associated and predictors of kidney function decline were analyzed.

  Results: One hundred and seventy out of 324 patients suffered a fall of eGFR (group A), (median of fall −1.6 ml/min/1.73 m2/year (−3.0, −0.7)). Male gender, albuminuria > 100 mg/day and higher pulse pressure were associated to progression in our cohort (group A). Hyperuricemia was more frequent among patients with higher kidney disease progression (group A2) (33% vs 49%, p = 0.04) when comparing to lower progression (group A1). Adjusted Cox regression models showed that hyperuricemia, pulse pressure and albuminuria were independent predictors of kidney disease progression (HR 1.67 (1.06–2.63), p = 0.023; 1.02 (1.01–1.03), p = 0.001 and HR: 2.14 (1.26–3.64), p = 0.005, respectively). Kidney disease progression was higher in patients with unilateral renal atrophy or agenesis than nephrectomy (log rank: 7.433, p = 0.006).

  Conclusions: Hyperuricemia is independently associated with kidney disease progression in patients with reduce functioning renal mass.

• English

  Introducción: Grandes estudios observacionales han asociado el aumento del ácido úrico sérico con el desarrollo y progresión de ERC. Esta hipótesis no ha sido contrastada en pacientes con disminución de la masa renal.

  Métodos: Estudio retrospectivo en 324 pacientes de una consulta externa que se siguieron durante 60 (36-98) meses. Se recogieron anualmente variables demográficas, factores cardiovasculares, fármacos concomitantes, albuminuria y niveles de ácido úrico. El endpoint primario era la caída anual de FGe por MDRD-4. Dividimos la muestra en tres grupos (A1:

  pacientes con caída del FGe menor que la media, A2: mayor que la media, B: sin caída del FGe). Analizamos los predictores del empeoramiento de la función renal.

  Resultados: 170 de los 324 pacientes tuvieron caída de FGe (grupo A) (media de caída - 1.6 ml/min/1.73 m2/an˜ o (-3.0, -0.7). Se asociaron con la progresión de ER género masculino, albuminuria > 100 mg/d e hipertensión arterial. La hiperuricemia fue más frecuente entre los pacientes con mayor progresión de ER (grupo A2) (33% vs 49%, p = 0.04) comparado con los de menor progresión (grupo A1). El modelo de regresión de Cox ajustado mostró que la hiperuricemia, la presión arterial y la albuminuria eran predictores independientes de la progresión de enfermedad renal: HR 1.67 (1.06-2.63), p = 0.023; 1.02 (1.01-1.03), p = 0.001 y HR:

  2.14 (1.26-3.64), p = 0.005). La progresión de ER fue mayor en la atrofia o agenesia renal que en la nefrectomía (log rank: 7.433, p = 0.006).

  Conclusión: La hiperuricemia se asocia de forma independiente con la progresión de enfermedad renal en pacientes con masa renal disminuida.