César García-Cantón

Vascular calcification and 25-hydroxyvitamin D levels in non-dialysis patients with chronic kidney disease stages 4 and 5

BACKGROUND Cardiovascular disease (CVD) is the leading cause of death among chronic kidney disease (CKD) patients. Vascular calcification is highly prevalent in this population and is an independent predictor of cardiovascular mortality. Vascular calcification in uraemic patients is known to be an active and regulated process subject to the action of many promoting and inhibitory factors. The role of vitamin D in this process remains controversial. We evaluated the relationship between serum levels of 25-hydroxyvitamin D (25(OH)D) and vascular calcification evaluated by plain X-ray images, in predialysis patients with CKD stages 4 and 5. METHODS We performed a cross-sectional study with 210 CKD patients stages 4 and 5 managed at our predialysis unit. Patients were 63.5 ± 13 years of age, 60.5% males, 64.8% diabetics and 47.1% with a history of CVD. Plain X-ray images of pelvis, hands and lateral lumbar spine from all subjects were studied for calculation of semiquantitative vascular calcification scores as described by Adragao and Kauppila. RESULTS We found a high prevalence of vascular calcification in our population. Adragao scores revealed only 47 patients (22.4%) without vascular calcification and 120 (57.1%) with scores higher than 3. Kauppila scores revealed only 29 patients (13.8%) without aortic calcifications and 114 patients (54.3%) with scores higher than 7. Higher vascular calcification scores were related to older age, diabetes, history of CVD and lower levels of 25(OH)D. Only 18.5% of patients had adequate levels of 25(OH)D (> 30 ng/mL), 53.7% of them had insufficient levels (15-30 ng/mL) and 27.8% had deficient levels (< 15 ng/mL). Multivariate analysis showed that age, diabetes and CVD were directly associated and 25(OH)D levels were inversely associated with vascular calcifications. CONCLUSIONS Our results show an independent and negative association between serum levels of 25(OH)D and vascular calcification. Further and larger prospective studies are needed to clarify the possible role of vitamin D deficiency in the development of vascular calcification in CKD patients.

Non-albuminuric renal disease among subjects with advanced stages of chronic kidney failure related to type 2 diabetes mellitus.

Abstract Urinary albumin excretion has been consistently found to be normal in a significant number of subjects with early stages of diabetic kidney disease. This study was aimed to estimate the prevalence and characteristics of non-albuminuric chronic kidney disease associated with type 2 diabetes mellitus among subjects who reach advanced stages of renal failure. Study population was composed of incident patients with advanced chronic kidney disease (glomerular filtration rate <30 mL/min) related to type 2 diabetes in a tertiary hospital from Gran Canaria (Spain) during a period of 2 years. Subjects were classified as normoalbuminuric (urinary albumin-to-creatine ratio [UACR] <30 mg/g), microalbuminuric (UACR ≥30 and <300 mg/g), or proteinuric (UACR ≥300 mg/g). Of 78 eligible patients, 21.8% had normoalbuminuria, 20.5% had microalbuminuria, and 57.7% had proteinuria. Individuals with normoalbuminuria were mostly women and had a lower prevalence of smoking and polyneuropathy than subjects with microalbuminuria or proteinuria. They also presented greater measures of body mass index and waist circumference, higher values of total and LDL cholesterol, and lower values of HbA1c and serum creatinine than subjects with microalbuminuria or proteinuria. Multivariate analysis demonstrated that female sex (positively) and HbA1c and polyneuropathy (negatively) were independently associated with absence of albuminuria. In conclusion, around 20% of subjects with diabetes-related advanced chronic kidney disease, characteristically women, have normal urinary albumin excretion. HbA1c and polyneuropathy are inversely related to this non-albuminuric form of nephropathy.

Partial purification of a renotropic activity from plasma of uninephrectomized human subjects.

A renotropic factor was partially purified by sequential gel filtration and anion exchanger chromatography from plasma of human kidney transplantation donors and a renal cancer patient after uninephrectomy. This activity increased the rate of [3H]thymidine incorporation into DNA in rat cortical tubules, but not in rat liver cells, within the range of 100-200 ng/ml protein. The renotropic activity was detected between 7 and 12 days after uninephrectomy, and at least in 1 case decreased thereafter. This activity was undetected in gel-filtrated plasma of patients after a nonurological surgical procedure. The potency of this renotropic activity and its elution by gel filtration are similar to those displayed by a renal growth factor activity isolated from uninephrectomized rat plasma, as recently reported.

Supervivencia comparada a medio plazo entre diálisis peritoneal y hemodiálisis según el acceso vascular de inicio

En un estudio publicado en 2011 se ob - servo que en la Comunidad Canaria la supervivencia de los pacientes incidentes en dialisis peritoneal (DP) es mejor que la de los pacientes incidentes en hemodialisis (HD). El inicio de HD con cateter venoso central condi - ciona un peor pronostico, por lo que el acceso vascular de inicio podria condicionar la comparacion de la su - pervivencia entre ambas modalidades. Objetivo: Reali - zar un estudio comparativo en nuestra comunidad de la supervivencia a medio plazo de los pacientes incidentes en tratamiento renal sustitutivo segun la modalidad, separando a los pacientes incidentes en HD segun el acceso vascular de inicio: acceso vascular arteriovenoso desarrollado o cateter venoso central. Material y meto - dos: Se trata de un estudio de cohortes longitudinal ret - rospectivo, que incluyo todos los pacientes incidentes en tratamiento renal sustitutivo entre enero de 2005 y diciembre de 2010 seguidos hasta diciembre de 2011 en tres de los grandes hospitales de la Comunidad Canaria y se dividieron, segun la modalidad de inicio, en DP, HD con acceso vascular desarrollado (HD-FAV) y HD con ca - teter venoso central (HD-Cat). Se estimaron las curvas de supervivencia en los distintos grupos mediante Kaplan- Meier y se aplico un modelo de riesgos proporcionales de Cox de supervivencia para estimar los riesgos rela - tivos de mortalidad de DP, frente a HD-FAV y HD-Cat, ajustando para edad e indice de comorbilidad de Charl - son. Posteriormente se realizo el mismo analisis por sub - grupos definidos por la edad y presencia de diabetes. Resultados: Se incluyeron 1110 pacientes, mediana de edad 63 anos, 56 % diabeticos. El analisis de Kaplan- Meier muestra una mejor supervivencia de DP (66 me - ses) frente a HD-Cat (41 meses), log-rank p < 0,001, no existiendo diferencia entre DP y HD-FAV (67 meses). En la regresion de Cox el riesgo relativo de mortalidad de la HD-Cat frente a la DP fue de 2,270 (1,573-3,276); p < 0,001. No se observo diferencia entre los pacientes HD- FAV y DP 0,993 (0,646-1,525). El analisis por subgrupos muestra estos mismos resultados en diabeticos y no dia - beticos, y en los pacientes mas jovenes y en los mas ano - sos. Conclusiones: La mejor supervivencia en DP frente a HD observada en el registro de enfermos renales de la Comunidad Canaria parece a expensas de los pacientes incidentes en HD-Cat, no observandose diferencia entre DP y HD-FAV. Estos resultados podrian sugerir que, en nuestro medio, aquellos pacientes en los que, optando inicialmente por HD, no se consigue un acceso vascu - lar desarrollado en la etapa predialisis podrian obtener un beneficio de supervivencia ofreciendoles la DP como tecnica de inicio, al menos hasta disponer de un acceso vascular definitivo.INTRODUCTION A study published in 2011 showed that patients in the Canary Islands, who were incident in peritoneal dialysis (PD) had better survival than those who were incident in hemodialysis (HD). Since initiating hemodialysis with central venous catheter is associated with worse prognosis, it would be possible that the initial vascular access influences the results of survival comparison between both groups. OBJECTIVE To conduct a comparative medium-term survival study of patients incident in renal replacement therapy with different modalities in our community, classifying those incident in hemodialysis according to the initial vascular access: established arteriovenous vascular access or central venous catheter. MATERIAL AND METHOD Retrospective longitudinal cohort study including all patients who were incident in renal replacement therapy between January 2005 and December 2010, with follow-up until December 2011, in three large hospitals of the Canary Islands. Patients were classified according to the initial modality: PD, HD with established vascular access (HD-FAV) or HD with central venous catheter (HD-Cat). Kaplan-Meier survival curves were estimated for each group and a Cox proportional hazards survival model was used to estimate relative mortality risk for DP as compared to HD-FAV and HD-Cat, adjusting for age and Charlson comorbidity index. An equivalent analysis was then conducted on subgroups defined by age or by the presence of diabetes. RESULTS 1110 patients were included, with a median age of 63 years, 56% of them were diabetic. A Kaplan-Meier analysis showed better survival for PD (66 months) as compared to HD-Cat (41 months), Log Rank p<.001, with no difference between DP and HD-FAV (67 months). Cox regression RR of mortality for HD-Cat versus PD was 2.270 (1.573-3.276); p<.001; no differences were found between HD-FAV and PD patients 0.993 (0.646-1.525) n.s. Subgroup analysis showed equivalent results for diabetic and non-diabetic patients as well as for younger or older ones. CONCLUSIONS better survival of PD patients as compared to HD ones, observed in the Canary Islands, seems to be based on incident HD patients with central venous catheter, while no differences were found between PD and HD with established vascular access. These results could suggest that patients in our community, for whom a vascular access cannot be achieved in predialysis, could have better survival if PD is offered as initial technique, at least until a vascular access is available.

Relationship between Anemia and Serum Concentrations of Calcium and Phosphorus in Advanced Non-Dialysis-Dependent Chronic Kidney Disease

Background/Aims: Different biochemical abnormalities of metabolic bone disease have been associated with anemia of chronic kidney disease (CKD), mainly in hemodialysis patients. However, all of these abnormalities are closely inter-related and their individual effect on the development of anemia is uncertain. This study was aimed to assess the relationship between anemia and a set of metabolic bone disease biomarkers in a cohort of adult patients with advanced non-dialysis-dependent CKD. Methods: The sample consisted of 382 patients submitted to a Nephrology Unit for evaluation of advanced CKD in a tertiary hospital from Gran Canaria during 3 years. Associations between anemia and serum levels of calcium (albumin-corrected), phosphorus, PTH, 25-hydroxivitamin D (25(OH)D3) and alkaline phosphatase were analyzed by using logistic regression models with adjustment for other demographic, clinical and biochemical covariates potentially related to anemia and to bone mineral metabolism. Results: Serum levels of calcium and 25(OH)D3 (negatively) and phosphorus (positively) were significantly associated with anemia in an unadjusted logistic regression model. In a fully adjusted multivariable model, the OR for anemia was 0.29 (95% CI 0.16-0.49; p < 0.0001) for every 1 mg/dl increase in serum calcium and 2.19 (95% CI 1.55-3.15; p < 0.001) for every 1 mg/dl increase in serum phosphorus. Female sex and lower serum albumin levels were also independently associated with anemia. The inclusion of albumin in the adjusted model displaced the significance of 25(OH)D3. Conclusions: Circulating levels of calcium and phosphorus are strongly linked to anemia in patients with advanced non-dialysis CKD.

Papel de la fotoaféresis en el tratamiento del rechazo celular agudo refractario en trasplante renal

Extracorporeal photopheresis is an immunomodulatory technique based on the apoptotic effects of 8methoxypsoralen (8 MOP) and ultraviolet A (UVA) radiation on leukocytes. This technique is widely used in T-cell mediated disorders such as cutaneous T-cell lymphoma, graft-versus-host disease, rheumatoid arthritis and systemic lupus erythematosus. The use of this technique in the prophylaxis of acute rejection of lung or heart transplant is promising; however, scarce articles have been published on its application in case of acute cellular rejection refractory to conventional treatment in patients with kidney allograft.

Potential implications of the choice among three alternative treatment targets for apolipoprotein B100 in the management of patients with type 2 diabetes and chronic kidney disease

This study analyses discordance rates between attainment of therapeutic goals for apolipoprotein B100 (apoB) and both low-density lipoprotein–cholesterol (LDL-C) and non-high-density lipoprotein–cholesterol (non-HDL-C) in a sample of 152 patients with type 2 diabetes and chronic kidney disease from Gran Canaria (Spain), using treatment targets recommended by the American Diabetes Association/American College of Cardiology (ADA/ACC), the European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) and by a Spanish population-based study. Among subjects with LDL-C levels at therapeutic goal, apoB was above target in 16.3% (ADA/ACC), 6.5% (ESC/EAS) and 39.1% (population-based criteria), and among subjects with non-HDL-C levels at therapeutic goal, apoB was above target in 10.5% (ADA/ACC), 1.2% (ESC/EAS) and 29.6% (population-based criteria). These findings show that clinical management would be very differently altered depending on the criteria used to set treatment targets for apoB. Cut-off points derived from population data identify a greater number of subjects suitable for a more intensive lipid-lowering therapy.

Prevalence and determinants of the metabolic syndrome among subjects with advanced nondiabetes-related chronic kidney disease in Gran Canaria, Spain.

Abstract Background The relationship between the metabolic syndrome and mild chronic kidney disease (CKD) has been extensively studied. This study was aimed to estimate the prevalence and factors associated with the metabolic syndrome among subjects with advanced stages of nondiabetes-related CKD. Methods Study population was composed of incident patients with advanced CKD not related to diabetes in a tertiary hospital from Gran Canaria (Spain) since February 2011 to December 2014. Participants fulfilled a survey questionnaire and underwent physical examination and biochemical evaluation. Results The sample was composed of 167 subjects (mean age 63.9 ± 13.7 years; estimated glomerular filtration rate 21.9 ± 6.6 mL/min/1.73 m2). The prevalence of the metabolic syndrome was 68.9% (65.2% in men and 73.3% in women). Highest rates were observed in groups with chronic interstitial nephropathy (80%), CKD of uncertain etiology (76.7%) and CKD related to vascular causes (76.2%). Subjects with metabolic syndrome were older, had higher values of C-reactive protein and more often reported to have first-degree relatives with diabetes and to be physically inactive. In multivariate analyses, age (OR: 1.034 [CI 95%: 1.004–1.065]; p  =  0.024) and family history of diabetes (OR: 2.550 [1.159–5.608]; p  =  0.020) were independently associated with the metabolic syndrome. Conclusions The prevalence of the metabolic syndrome among subjects with advanced nondiabetes-related CKD is high, and greater than that observed in general Canarian population of similar age groups. Age and family history of diabetes are the two factors more strongly associated with the metabolic syndrome in this population.