Alteraciones en el metabolismo mineral óseo en pacientes con urolitiasis de repetición y polimorfismos del gen del receptor de la vitamina D. Resultados preliminares / Alterations in bone mineral metabolism in patients with calcium kidney stone disease and polymorphism of vitamin D receptor, preliminary results

Existe controversia sobre la afectación ósea en la litiasis renal cálcica. Por otro lado, algunos estudios genéticos han encontrado asociación entre los polimorfismos del receptor de la vitamina D (VDR) y la urolitiasis.Objetivo principal: Relacionar la nefrolitiasis cálcica de repetición con el metabolismo óseo y los polimorfismos del gen del VDR. Material y métodos: Estudio de casos y controles, estando el grupo de casos formado por 51 pacientes con litiasis renal de repetición, que subdividimos enno hipercalciúricos (NHC, n = 27), hipercalciúricos absortivos (HCA, n = 10) e hipercalciúricosrenales (HCR, n = 14); el grupo control, formado por 21 sujetos sin historia de litiasis renal ni hipercalciuria. Se les determinaron parámetros del metabolismo fosfo-cálcico, marcadores de remodelado óseo, densidad mineral ósea (DMO) en columna lumbar y en cuello femoral, y polimorfismos del gen del VDRpara los loci b, a y t. Resultados: Los pacientes litiásicos presentaron frente a los controles una DMO inferior tanto en L2-L4 como en cuello femoral (Z-score, p = 0,045 y 0,031), niveles superiores de 1,25 (OH)2 vitamina D (p = 0,002) e inferiores de PTH (p = 0,049), y una menor ingesta cálcica (p < 0,001). Los HCA mostraron una mayor DMO frente a los NHC (sólo significativo en cuello femoral). Los pacientes con LRC no mostraron diferencias en las frecuencias genotípicas estudiadas frente a los controles. Al reagrupar los alelos, sólo se apreció una menor frecuencia del genotipo BB respecto al Bb-bb, y del tt frente al TT-Tt, en los pacientes litiásicos (p =0,098 y p = 0,051, respectivamente). Conclusiones: La litiasis renal cálcica pareceinfluir en la DMO de cuello femoral. Los pacientes litiásicos mostraron niveles elevados de 1,25 (OH)2 vitamina D, posiblemente relacionado con la baja dieta cálcica. Los genotipos homocigóticos BB y tt parecen ser menos frecuentes entre los pacientes con litiasis renal cálcica

Bone health, within calcium kidney stone disease is a matter of controversy. On the other hand, some genetic studies have shown an association between some Vitamin Dreceptor polymorphisms and calcium kidney stone disease. Main objective: To study the possible association between calcium kidney stone disease with bone metabolismand some Vitamin D receptor polymorphisms. Patients and methods: This is a casecontrol study, with seventy-two subjects of both genders divided into two groups: Group I: cases, composed by 51 patients suffering from calcium kidney stone disease. Twenty-four of them had no hypercalciuria, 16 had absortive hypercalciuria and 11 had renal hypercalciuria. Group II: controls, composed by 21 people, without either urolithiasis or hypercalciuria. We performed a complete study including biochemical markers of bone mineral remodelling, bone mineral density (BMD) was estimatedboth in the lumbar spine (L2-L4) and femoral neck, and also VDR polymorphism for the loci b, a and t. Results: Patients with urolithiasis had lower values of BMD both in the lumbar spine and femoral neck, compared to controls. Z-score were lower in the lumbar spine and femoral neck (p = 0.045 y 0.031, respectively). Those patients with absorptive hypercalciuria had higher BMD in the femoral neck than those with renal hypercalciuria and non-hypercalciuria. Because they had more weight and height all the statistical study was performed alter adjusting by these two variables and statisticalsignificance was then only stated between patients with hypercalciuria and without it. Patients with urolithiasis had higher values of 1.25 (OH)2 vitamin D (p = 0.002), and lower of PTH (p = 0.049), without any relationship to hypercalciuria and its subtypes.Seventy six percent of the patients had a daily calcium intake lower than 800 mg/day. The distribution of VDR alleles in patients with urolithiasis was similar to controls, although after grouping genotypes, a lower distribution of BB and tt polymorphisms wereobserved in patients suffering from urolithiasis. Conclusions: Calcium kidney stone diseaseby itself produces a decrease in BMD, more intense in femoral neck, independently the presence or absence of hypercalciuria. Patients suffering from urolitihiasishave higher values of 1.25 (OH)2 vitamin D than non-hypercalciuric patients and lower values of PTH probably due to a low dietary calcium intake. In our populationstudied there is no relationship between VDR polymorphisms and the presence of calcium kidney stone disease. Because the reduced number of patients of our study,more studies are needed to obtain definitely conclusions

[Alterations in bone mineral metabolism in patients with calcium kidney stone disease and polymorphism of vitamin D receptor. Preliminary results]. / Alteraciones en el metabolismo mineral óseo en pacientes con urolitiasis de repetición y polimorfismos del gen del receptor de la vitamina D. Resultados preliminares.

UNLABELLED: Bone health, within calcium kidney stone disease is a matter of controversy. On the other hand, some genetic studies have shown an association between some Vitamin D receptor polymorphisms and calcium kidney stone disease. MAIN OBJECTIVE: To study the possible association between calcium kidney stone disease with bone metabolism and some Vitamin D receptor polymorphisms. PATIENTS AND METHODS: This is a case-control study, with seventy-two subjects of both genders divided into two groups: Group I: cases, composed by 51 patients suffering from calcium kidney stone disease. Twenty-four of them had no hypercalciuria, 16 had absortive hypercalciuria and 11 had renal hypercalciuria. Group II: controls, composed by 21 people, without either urolithiasis or hypercalciuria. We performed a complete study including biochemical markers of bone mineral remodelling, bone mineral density (BMD) was estimated both in the lumbar spine (L2-L4) and femoral neck, and also VDR polymorphism for the loci b, a and t. RESULTS: Patients with urolithiasis had lower values of BMD both in the lumbar spine and femoral neck, compared to controls. Z-score were lower in the lumbar spine and femoral neck (p =0,045 y 0,031, respectively). Those patients with absorptive hypercalciuria had higher BMD in the femoral neck than those with renal hypercalciuria and non-hypercalciuria. Because they had more weight and height all the statistical study was performed alter adjusting by these two variables and statistical significance was then only stated between patients with hypercalciuria and without it. Patients with urolithiasis had higher values of 1,25 (OH)2 vitamin D (p=0,002), and lower of PTH (p=0,049), without any relationship to hypercalciuria and its subtypes. Seventy six percent of the patients had a daily calcium intake lower than 800 mg/day. The distribution of VDR alleles in patients with urolithiasis was similar to controls, although after grouping genotypes, a lower distribution of BB and tt polymorphisms were observed in patients suffering from urolithiasis. CONCLUSIONS: Calcium kidney stone disease by itself produces a decrease in BMD, more intense in femoral neck, independently the presence or absence of hypercalciuria. Patients suffering from urolitihiasis have higher values of 1,25 (OH)2 vitamin D than non-hypercalciuric patients and lower values of PTH probably due to a low dietary calcium intake. In our population studied there is no relationship between VDR polymorphisms and the presence of calcium kidney stone disease. Because the reduced number of patients of our study, more studies are needed to obtain definitely conclusions.

[Early treatment of secondary hyperparathyroidism in moderate renal insufficiency: low-phosphorus diet versus calcium carbonate]. / Tratamiento precoz del hiperparatiroidismo secundario en insuficiencia renal moderada: dieta baja en fósforo frente a carbonato cálcico.

Calcitriol deficiency and phosphorus retention are mechanisms involved in the pathogenesis of renal hyperparathyroidism. The aim of this study was to evaluate the effect of dietary phosphorus restriction versus calcium carbonate treatment for one month on PTH and calcitriol levels in patients with mild renal failure. We studied two groups of patients: Group I: 21 patients (14M/7F); mean age 61 years old; mean glomerular filtration rate 51 ml/min. Their diet contained phosphorus 700 mg/day. Group II: 30 patients (21M/9F); mean age 58; mean glomerular rate 56 ml/min. They were divided in two subgroups: 18 patients treated with calcium carbonate 2.5 g/day and 12 patients with 5 g/day. Serum PTH, calcitriol, 25(OH)D3, calcium, phosphorus and urinary excretion of calcium and phosphorus were measured before and after a 30 day period. The low phosphorus diet (Group I) resulted in a significant decrease in PTH levels (81.3 +/- 35 vs 71 +/- 39 pg/ml, p < 0.05) and significant increase in calcitriol levels (22.4 +/- 4.4 vs 33.4 +/- 7.5 pg/ml, p < 0.05). In our study calcium carbonate treatment (Group II) had no effect on PTH and calcitriol levels.

Tratamiento precoz del hiperparatiroidismo secundario en insuficiencia renal moderada: dieta baja en fósforo frente a carbonato cálcico / Early treatment of secondary hyperparathyroidism in moderate renal failure: a low phosphorus diet versus calcium carbonate

El déficit de calcitriol y la retención de fósforo son mecanismos implicados en la etiología del hiperparatiroidismo secundario. El objetivo de este trabajo fue comparar el efecto sobre los niveles de calcitriol y PTH de una dieta baja en fósforo frente al tratamiento con carbonato cálcico en pacientes con insuficiencia renal moderada durante un mes. Se estudiaron dos grupos de pacientes. Grupo I: 21 pacientes (14H/7M) con una edad media de 61 años y un filtrado glomerular medio de 51 ml/min a los que se sometió a una dieta con 700 mg/día de fósforo. Grupo II: 30 pacientes (21H/9M) con una edad media de 58 años y un filtrado glomerular de 56 ml/min, a los que se trató con 2,5 g/día de carbonato cálcico (18 pacientes) y 5 g/día (12 pacientes). Se midieron niveles de PTH, calcitriol, 25(OH)D3, calcio y fósforo séricos e índices urinarios fósforo/creatinina, calcio/creatinina y reabsorción tubular de fosfato de forma basal y al mes. En el grupo tratado con dieta baja en fósforo hubo disminución de las cifras de PTH (81,3 ± 35 vs 71 ± 39 pg/ml, p < 0,05) y aumento de las cifras de calcitriol (22,4 ± 4,4 vs 33,4 ± 7,5 pg/ml, p < 0,05). En los grupos tratados con carbonato cálcico no hubo cambios en las cifras de PTH ni calcitriol. En ningún grupo se modificaron las cifras de calcio, fósforo sérico ni 25(OH)D3. Nuestros pacientes con insuficiencia renal moderada muestran cifras elevadas de PTH y valores de calcitriol en los límites inferiores de la normalidad. La dieta baja en fósforo se muestra efectiva el elevar los niveles de calcitriol y disminuir la PTH. El tratamiento con carbonato cálcico no modifica los valores de calcitriol y PTH en nuestros pacientes (AU)

Calcitriol deficiency and phosphorus retention are mechanisms involved in the pathogenesis of renal hyperparathyroidism. The aim of this study was to evaluate the effect of dietary phosphorus restriction versus calcium carbonate treatment for one month on PTH and calcitriol levels in patients with mild renal failure. We studied two groups of patients: Group I: 21 patients (14M/7F); mean age 61 years old; mean glomerular filtration rate 51 ml/min. Their diet contained phosphorus 700 mg/day. Group II: 30 patients (21M/9F); mean age 58; mean glomerular rate 56 ml/min. They were divided in two subgroups: 18 patients treated with calcium carbonate 2.5 g/day and 12 patients with 5 g/day. Serum PTH, calcitriol, 25(OH)D3, calcium, phosphorus and urinary excretion of calcium and phosphorus were measured before and after a 30 day period. The low phosphorus diet (Group I) resulted in a significant decrease in PTH levels (81.3 ± 35 vs 71 ± 39 pg/ml, p < 0.05) and significant increase in calcitriol levels (22.4 ± 4.4 vs 33.4 ± 7.5 pg/ml, p < 0.05). In our study calcium carbonate treatment (Group II) had no effect on PTH and calcitriol levels (AU)

[Effects of dietary phosphorus restriction on the production of 1,25(OH)2D3 (calcitriol) in patients with moderated renal failure]. / Efectos de una restricción de fósforo dietético en la producción de 1,25(OH)2D3 (calcitriol) en pacientes con insuficiencia renal moderada.

UNLABELLED: Calcitriol deficiency and phosphate retention are two main factors in the pathogenesis of renal hyperparathyroidism. In spite of normal serum levels, phosphate may have an important role even in moderate RI. The aim of this study was to evaluate the effect of dietary phosphorus restriction on serum levels of calcitriol in patients with moderate RI. We studied 21 patients (7 F/14 M); mean age 61.7 +/- 15 years old; corrected creatinine clearance 51.4 +/- 14 ml/m. Serum PTH, calcitriol 25(OH)D3, calcium, phosphorus and urinary excretion of calcium and phosphorus were measured before and after 30 days on phosphorus restricted diet (700 mg/day). RESULTS: [table: see text] CONCLUSIONS: Our patients with moderate RI have elevated serum levels of PTH while calcitriol was in the lower normal range. Dietary phosphorus restriction resulted in a significant decrease in PTH levels and a significant increase in serum calcitriol concentrations. The levels of 25(OH)D3 did not change in this study.

[Comparison of 4 processing methods for the diagnosis of peritonitis in patients undergoing chronic ambulatory peritoneal dialysis]. / Comparación de cuatro métodos de procesamiento para el diagnóstico de peritonitis en pacientes sometidos a diálisis peritoneal crónica ambulatoria.

BACKGROUND: Four methods for the diagnosis of peritonitis in patients submitted to chronic ambulatory peritoneal dialysis were evaluated. METHODS: Fluid from eighty-five patients undergoing peritoneal dialysis processed by the following techniques conventional, centrifugation, injection into conventional BACTEC bottles and in double volume BACTEC bottles. In addition, qualitative and quantitative counts of the number of leukocytes/mm3 of peritoneal dialysis, as well as the gram staining of the sediment obtained following centrifugation were carried out. RESULTS: Sixty-eight percent of the peritoneal dialysis fluid processed fulfilled criteria of peritonitis. Global sensitivity of the diagnostic techniques used was 62%. The sensitivities of the different methods were individually: conventional, 46%, centrifugation, 52%, injection into conventional BACTEC bottles, 53%, and injection into double volume BACTEC bottles 58%. Gram staining sensitivity was 9%. CONCLUSIONS: Direct injection of peritoneal dialysis in double volume BACTEC bottles is a useful technique for the etiologic diagnosis of peritonitis in patients submitted to chronic ambulatory peritoneal dialysis. In this study, its sensitivity was greater to that of the other methods evaluated allowing minimal handling and delay in the processing of the sample.