[Assessment of long-term renal function after nephrectomy. Study of 53 patients]. / Estudio de la función renal a largo plazo en 53 pacientes con nefrectomía por diversas causas.

BACKGROUND AND OBJECTIVE: Patients with unilateral nephrectomy maintain the remaining kidney function over time, as it has been described in healthy kidney donors. PATIENTS AND METHOD: We performed a cross-sectional study of 53 patients who were followed 5 or more years after nephrectomy. Serum creatinine, BUN, Glomerular Filtration Rate (GFR) (24 hours urine collection and Cockcroft formula), microalbuminuria, proteinuria, Body Mass Index and the annual loss rate of renal function were measured or calculated over the follow-up period. We retrospectively considered the presence of risk factors like diabetes, hypertension, microalbuminuria, dyslipemia, smoking habit, obesity and ACE inhibitors or angiotensin-receptor antagonists treatment. We divided our patients into two groups: group I (normal or mild renal failure: GFR > 50 cc/min and or serum creatinine < 1.4 mg/dL) and group II (moderate or severe renal failure). RESULTS: The main cause of nephrectomy was renal tuberculosis, followed by lithiasis and pyonephrosis. In addition, 7.5% of patients were kidney donors. At the time of study, 22.7% had diabetes, 60.4% hypertension and 39.6% were obese. The mean age was 60 years (37 years at the moment of nephrectomy). The GFR final mean was 53.6 cc/min (58.8 cc/min by Cockcroft formula). The mean renal function loss rate was 1 cc/min/year. 35% of the patients had moderate or severe kidney failure and were included in group II; 32% had proteinuria and 56.6% had abnormal microalbuminuria. The univariate risk factors analysis for the development of renal failure showed inter-group statistical significative differences in current age, nephrectomy age, microalbuminuria, proteinuria, and hypertension prevalence (p = 0.008). With regard to the progression rate, we found a significant correlation with final microalbuminuria (r = 0.358, p = 0.03). Current age and final proteinuria were found to be significant risk factors in the multivariate analysis. CONCLUSIONS: A high prevalence of renal insufficiency was found among patients with unilateral nephrectomy, which is mainly related to age and proteinuria. The renal function loss rate is slow and is influenced by microalbuminuria.

Estudio de la función renal a largo plazo en 53 pacientes con nefrectomía por diversas causas / Assessment of long-term renal function after nephrectomy. Study of 53 patients

Fundamento y objetivo: En pacientes con nefrectomía quirúrgica, la función renal se mantiene conservada durante largo tiempo, habiéndose descrito fundamentalmente en donantes sanos. Planteamos este estudio para conocer la evolución y los factores favorecedores de insuficiencia renal en nuestra población monorrena. Pacientes y método: En 53 monorrenos a quienes se había practicado una nefrectomía más de 5 años antes, se determinó el aclaramiento de creatinina, el aclaramiento por la fórmula de Cockcroft, la microalbuminuria y la proteinuria. Se recogieron factores de riesgo como diabetes, hipertensión, tratamiento con inhibidores de la enzima conversiva de la angiotensina y antagonistas del receptor de la angiotensina de tipo II, tabaquismo y obesidad. Incluimos los valores de creatinina, aclaramiento, Cockcroft y proteinuria de los últimos 5 años de seguimiento y se calculó la velocidad de pérdida de aclaramiento anual. Establecimos dos grupos de pacientes: grupo I, con función renal normal o leve insuficiencia (aclaramiento > 50 ml/min y/o creatinina < 1,4), y grupo II, con insuficiencia renal moderada o grave (aclaramiento < 50 ml/min). Resultados: La edad media fue de 60 años, al realizar la nefrectomía era de 37 años. La velocidad de disminución del filtrado glomerular fue de 1 ml/min/año. El 35,8% de los pacientes tenían insuficiencia renal; el 32%, proteinuria, y el 56,6%, microalbuminuria elevada. En el análisis de factores de riesgo para insuficiencia renal resultaron significativas la edad actual, la edad cuando se practicó la nefrectomía, microalbuminuria y proteinuria previas elevadas, e hipertensión arterial. Respecto a la velocidad de progresión, fueron factores de riesgo la microalbuminuria final e inicial y la proteinuria final. En el análisis multivariante fueron significativas para la insuficiencia renal la edad actual y la proteinuria final. Conclusiones: Se observa un porcentaje elevado de insuficiencia renal en monorrenos, que se relaciona fundamentalmente con la edad y con la proteinuria. La velocidad de pérdida de filtrado glomerular es lenta y está influida por la microalbuminuria

Background and objective: Patients with unilateral nephrectomy maintain the remaining kidney function over time, as it has been described in healthy kidney donors. Patients and method: We performed a cross-sectional study of 53 patients who were followed 5 or more years after nephrectomy. Serum creatinine, BUN, Glomerular Filtration Rate (GFR) (24 hours urine collection and Cockcroft formula), microalbuminuria, proteinuria, Body Mass Index and the annual loss rate of renal function were measured or calculated over the follow-up period. We retrospectively considered the presence of risk factors like diabetes, hypertension, microalbuminuria, dyslipemia, smoking habit, obesity and ACE inhibitors or angiotensin-receptor antagonists treatment. We divided our patients into two groups: group I (normal or mild renal failure: GFR > 50 cc/min and or serum creatinine < 1.4 mg/dL) and group II (moderate or severe renal failure). Results: The main cause of nephrectomy was renal tuberculosis, followed by lithiasis and pyonephrosis. In addition, 7.5% of patients were kidney donors. At the time of study, 22.7% had diabetes, 60.4% hypertension and 39.6% were obese. The mean age was 60 years (37 years at the moment of nephrectomy). The GFR final mean was 53.6 cc/min (58.8 cc/min by Cockcroft formula). The mean renal function loss rate was 1 cc/min/year. 35% of the patients had moderate or severe kidney failure and were included in group II; 32% had proteinuria and 56.6% had abnormal microalbuminuria. The univariate risk factors analysis for the development of renal failure showed inter-group statistical significative differences in current age, nephrectomy age, microalbuminuria, proteinuria, and hypertension prevalence (p = 0.008). With regard to the progression rate, we found a significant correlation with final microalbuminuria (r = 0.358, p = 0.03). Current age and final proteinuria were found to be significant risk factors in the multivariate analysis. Conclusions: A high prevalence of renal insufficiency was found among patients with unilateral nephrectomy, which is mainly related to age and proteinuria. The renal–function loss rate is slow and is influenced by microalbuminuria

The impact of donor age on the results of renal transplantation.

BACKGROUND: The use of elderly donors is becoming more frequent. An increase in the donor's age is associated with a greater incidence of delayed graft function (DGF), chronic allograft nephropathy (CAN) and worse graft survival. Poor renal graft function is a risk factor for cardiovascular (CV) complications and, finally, for mortality of the patients. METHODS: A total of 3365 adult patients transplanted in 1990 (n = 824), 1994 (n = 1075) and 1998 (n = 1466) with a functioning graft after the first year were included. The impact of donor age on renal function, DGF, acute rejection and other clinical factors was evaluated according to two donor and recipient age categories: young (< 60 years old) and elderly (> or =60 years old). Additionally, donor age was categorized by decades for the analysis of patient and graft survival, acute rejection and CV mortality. RESULTS: Donor mean age significantly increased during the three transplantation periods. A total of 478 out of 3365 donors were older than 60 years. Elderly donors showed an increased risk of DGF (38.9 vs 28.8%) and CAN (56.8 vs 46.2%). Mean serum creatinine at 3 and 12 months and proteinuria were significantly higher in the old donor group. Incidence and severity of acute rejection were similar in both groups. Graft and patient survival were significantly lower in the old donor group. Also, risk of mortality due to CV events was also significantly higher. A linear increase in risk of graft loss, patient death or CV mortality was observed when donor age was divided into 10 year increase subsets. CONCLUSIONS: Donor age is a strong predictor of CAN and graft loss. Patient survival is also affected by donor age, particularly by a higher risk of CV mortality.