Enrique Luna

Bio: Enrique Luna is an academic researcher. The author has contributed to research in topics: Transplantation & Kidney disease. The author has an hindex of 10, co-authored 43 publications receiving 280 citations.

Patterns of progression of chronic kidney disease at later stages.

Abstract: Background At later stages of chronic kidney disease (CKD), a pattern of linear and irreversible renal function decline is thought to be the most common. The objective of this study was to describe the characteristics of the different patterns of CKD progression, and to investigate potentially modifiable factors associated with the rate of decline of renal function. Methods This was a retrospective, observational study in a cohort of adult patients with CKD Stage 4 or 5 not on dialysis. Decline in renal function was estimated as the slope of the individual linear regression line of estimated glomerular filtration rate (eGFR) over time. The following patterns of CKD progression were considered: unidentifiable, linear, nonlinear (curvilinear) and positive (improvement of renal function). Results The study group consisted of 915 patients (mean ±SD age 65 ± 14 years, 48% females, median follow-up time 16 months). A linear pattern was observed in 38%, unidentifiable in 23%, nonlinear in 24% and positive in 15% of the study patients. The mean eGFR slope was: -3.35 ± 4.45 mL/min/year. Linear and unidentifiable patterns were associated with more rapid loss of renal function. By multiple linear and logistic regression analysis, the magnitude of proteinuria, the systolic blood pressure and the treatment with dual renin-angiotensin system blockade were associated with more rapid CKD progression. On the contrary, older age and discontinuation of commonly prescribed medication with potential influence on renal function or eGFR measurements were associated with slower CKD progression. Conclusions A majority of patients with advanced CKD show patterns of renal function decline different from linear, and several of the main determinants of CKD progression are potentially modifiable.

Incidence of diabetes mellitus requiring insulin treatment after renal transplantation in patients with hepatitis C

Abstract: Background. Hepatitis C virus (HCV) infection has been associated with an increased incidence of diabetes mellitus, both in the general population and among transplant patients. Methods. To test this hypothesis, we reviewed the records of 1614 patients who had undergone renal transplant at six Spanish centres between 1992 and 1998. We established the rate of onset of diabetes mellitus requiring > I month of treatment with insulin (insulin-treated diabetes mellitus, I-TDM) among the 177 patients showing HCV antibody seropositivity at the time of transplant (HCV+ group). As controls. 177 HCV patients were selected who had received a kidney allograft immediately before or after the study patients at the same centre. Results. The HCV+ patients were well matched with controls in terms of characteristics (except a longer time on dialysis) and immunosuppressive treatment. After a mean follow-up of 44 months, 28 cases of I-TDM were diagnosed (9.6% in HCV+ and 6.2% HCV-, not significant (NS); odds ratio 1.6; 95% confidence interval 0.75-3.50). The onset of I-TDM was somewhat later in HCV+ patients (467 days vs 292 days in HCV- patients, NS). Multivariate analysis identified the following prognostic factors for I-TDM onset: age and BMI at the time of transplant, and polycystic kidney disease as the underlying cause of chronic renal insufficiency. No correlation was found with HCV positivity or time on dialysis. Conclusions. We were unable to confirm a greater incidence of post-renal transplant insulin-requiring diabetes in association with HCV infection. However, the observed tendency towards such an association suggests that the follow-up period would need to be extended.

Dolor músculo-esquelético en pacientes con enfermedad renal crónica

Abstract: Resumen Introduccion El dolor musculo-esqueletico cronico (DMEC) es un sintoma muy frecuente en pacientes con enfermedad renal cronica (ERC), y contribuye de forma importante al deterioro de la calidad de vida. Objetivos Determinar la prevalencia y caracteristicas clinicas asociadas al DMEC en pacientes con ERC avanzada no en dialisis, analizar su relacion con otros sintomas uremicos y su significado pronostico. Material y metodos Estudio transversal en el que se analizo la sintomatologia uremica de pacientes no seleccionados remitidos por ERC estadio 4 y 5 predialisis. Para caracterizar aquellos que presentaban DMEC, ademas de los datos demograficos, antropometricos, la comorbilidad y la funcion renal, tambien se recogieron parametros de inflamacion, acido urico, metabolismo oseo-mineral incluyendo 25-hidroxi-colecalciferol (25-OHCC), creatincinasa, y farmacos de potencial interes como alopurinol, estatinas y agentes estimulantes de eritropoyetina. Resultados Se incluyo a 1.169 pacientes con edad media de 65 ± 15 anos; el 54% eran hombres. Un 38% de los pacientes referia DMEC, y este sintoma fue mas frecuente en mujeres que en hombres (49 vs. 28%; p Aunque los pacientes con DMEC tenian una peor supervivencia, un analisis multivariante con ajuste simple a datos demograficos descarto que el DMEC fuera un determinante independiente de la mortalidad. Conclusiones El DMEC es muy prevalente en pacientes con ERC avanzada, y se asocia con otros sintomas comunes de la uremia cronica. Al igual que en la poblacion general, caracteristicas como sexo femenino, edad avanzada, obesidad y comorbilidad estan mas frecuentemente asociados al DMEC. La elevacion de los marcadores de inflamacion asociada al DMEC podria ser un hallazgo relevante para explicar su patogenia.

[Serum uric acid and C-reactive protein levels in patients with chronic kidney disease].

Abstract: Either inflammation or hyperuricemia has been related with increased cardiovascular risk and mortality. A hypothetical relationship between serum uric acid levels (SUA) and inflammatory markers has never been tested in chronic kidney disease (CKD) patients. The purpose of this study was to determine the prevalence of increased C-reactive protein (CRP) levels in CKD patients, and to test the hypothesis of a relationship between SUA and CRP levels. The study group consisted of 337 patients (174 males, mean age 63 +/- 16 years) with advanced chronic renal failure not yet on dialysis. None of them had overt inflammatory or infectious diseases. High sensitivity CRP levels were analyzed as a binary (above or below median value), or continuous variable (log-transformed CRP), by multiple logistic or linear regression analysis, respectively. Demographics, clinical, and biochemical characteristics, including SUA levels, were the variables tested in these analysis. In a subset of 169 patients without diabetes, the same analysis were carried out, with the inclusion of fasting insulin levels and HOMA-IR as independent variables. Median CRP level was 3.25 mg/L, and mean SUA level was 7.59 +/- 1.94 mg/dl. Patients with CRP levels above the median had significantly higher mean SUA level than that of the rest of study patients (7.93 +/- 1.79 vs 7.24 +/- 2.03 mg/dl, p = 0.001). SUA levels correlated significantly with log-transformed CRP levels (r = 0. 16, p = 0.0022). The relationship between SUA and CRP levels remained statistically significant after adjustment for age, sex, comorbid index, obesity, residual renal function, diuretic and allopurinol treatment, in the multivariate logistic and linear regression models (OR: 1.296, p = 0.0003; and beta: 0.204, p = 0.0002). The significant association between SUA and CRP levels did not change when HOMA-IR and fasting insulin levels were included as independent variables in the subset of 169 patients without diabetes. In conclusion, SUA levels are related with CRP levels in CKD patients.

Importancia relativa de los factores determinantes de los niveles séricos de 25-hidroxi-colecalciferol en la enfermedad renal crónica

Abstract: Resumen Introduccion El origen de la carencia de vitamina D en la enfermedad renal cronica (ERC) parece multifactorial, pero es incierta la importancia relativa de cada uno de sus potenciales determinantes. Objetivos Determinar los factores asociados a los niveles de 25-hidroxi-colecalciferol (25OHD) y su importancia relativa en una cohorte de pacientes con ERC predialisis. Material y metodos Se incluyeron pacientes incidentes en una consulta de ERC, excluyendo a aquellos que recibian suplementos de vitamina D o anticonvulsivantes. Ademas de los datos demograficos y clinicos, se analizo la influencia de la actividad fisica, estacion del ano de la extraccion, y tratamiento con estatinas, antiangiotensina e inhibidores de la xantino-oxidasa. Para la estimacion de la importancia relativa se utilizo el metodo de ponderacion relativa de Johnson, expresando los resultados como porcentajes de contribucion al R multiple. Resultados Se estudiaron 397 pacientes, de los cuales 30 fueron excluidos. La concentracion media de 25OHD fue de 13,7 ± 7,4 ng/ml, presentando unos niveles inferiores a 20 ng/ml el 81% de los pacientes. Por regresion lineal multiple y ponderacion relativa, los principales determinantes de unos niveles mas bajos de 25OHD fueron por orden de importancia: una mayor proteinuria (28,5%), mayor edad (21,4%), disminucion de la actividad fisica (19,4%), sexo femenino (19,3%), y menor bicarbonato serico (11,4%). Conclusion La magnitud de la proteinuria y la edad son los factores con mayor importancia relativa como determinantes de los niveles de 25OHD en la ERC.

Vitamin D in Chronic Kidney Disease and Dialysis Patients.

Abstract: Vitamin D deficiency (<20 ng/mL) and insufficiency (20–29 ng/mL) are common among patients with chronic kidney disease (CKD) or undergoing dialysis. In addition to nutritional and sunlight exposure deficits, factors that affect vitamin D deficiency include race, sex, age, obesity and impaired vitamin D synthesis and metabolism. Serum 1,25(OH)2D levels also decrease progressively because of 25(OH)D deficiency, together with impaired availability of 25(OH)D by renal proximal tubular cells, high fibroblast growth factor (FGF)-23 and decreased functional renal tissue. As in the general population, this condition is associated with increased morbidity and poor outcomes. Together with the progressive decline of serum calcitriol, vitamin D deficiency leads to secondary hyperparathyroidism (SHPT) and its complications, tertiary hyperparathyroidism and hypercalcemia, which require surgical parathyroidectomy or calcimimetics. Kidney Disease Outcomes Quality Initiative (KDOQI) and Kidney Disease Improving Global Outcomes (KDIGO) experts have recognized that vitamin D insufficiency and deficiency should be avoided in CKD and dialysis patients by using supplementation to prevent SHPT. Many vitamin D supplementation regimens using either ergocalciferol or cholecalciferol daily, weekly or monthly have been reported. The benefit of native vitamin D supplementation remains debatable because observational studies suggest that vitamin D receptor activator (VDRA) use is associated with better outcomes and it is more efficient for decreasing the serum parathormone (PTH) levels. Vitamin D has pleiotropic effects on the immune, cardiovascular and neurological systems and on antineoplastic activity. Extra-renal organs possess the enzymatic capacity to convert 25(OH)D to 1,25(OH)2D. Despite many unanswered questions, much data support vitamin D use in renal patients. This article emphasizes the role of native vitamin D replacement during all-phases of CKD together with VDRA when SHPT persists.