Evaluation of bone microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) in hemodialysis patients.

UNLABELLED: Hemodialyzed patients have decreased bone strength not completely characterized. We evaluated bone microarchitecture in hemodialysis patients and compared it to that of subjects without renal disease by high-resolution peripheral quantitative computed tomography (HR-pQCT). Hemodialysis patients have a marked decreased in cortical density, thickness, and area with significant reduction in trabecular parameters that correlated with the severity of secondary hyperparathyroidism only in women. INTRODUCTION: Although fracture risk is greatly increased in dialysis patients, the corresponding decreased in bone strength has not been completely characterized. METHODS: We evaluated volumetric bone mineral density (vBMD) and bone microstructure by HR-pQCT at the distal radius and tibia in 50 hemodialyzed (HD) patients (30 females, mean age 53.2 ± 6 years and 20 males, mean age 59.1 ± 11 years) and 50 sex- and age-matched controls. RESULTS: At the distal radius HD, women showed a 29% reduction in total and trabecular density and trabecular bone volume fraction (p < 0.0001) compared to controls. Trabecular number was reduced by 25% (p < 0.0001), while trabecular separation was increased by 51%. Cortical thickness (-40%, p < 0.0001) and cortical area (-42%, p < 0.0001) were the parameters most reduced, while compact density was the parameter least reduced (-15%, p < 0.0001). Similar findings were found at the tibia. In HD men, HR-pQCT at the distal radius and tibia showed a reduction in volumetric density and microstructure parameters to a lesser extent than in women. In the hemodialyzed group, cortical thickness at the radius was negatively correlated with age both in women and men. At the distal radius and tibia, we found significant negative correlations between Log iPTH and total alkaline phosphatase with cortical vBMD(r = -0.48, p < 0.01; r = -0.69, p < 0.001), thickness (-0.37, p < 0.05; r = -0.60, p < 0.001), and area ((r = -0.43, p = 0.02; r = -0.65, p < 0.001) but only in women. CONCLUSION: We conclude that hemodialysis patients have a marked decreased in cortical density, thickness, and area with significant reduction in trabecular parameters that correlated with the severity of secondary hyperparathyroidism only in women.

[Relationship between weight, body composition and bone mass in peritoneal dialysis]. / Relación entre peso, composición corporal y masa osea en diálisis peritoneal.

Patients in chronic dialysis show a decrease in total bone mass. The factors that determine this decrease are not well known. In normal populations weight and its compartments are important determinants of bone mass. We studied total bone mineral content (TBMC), a measure of bone mass, and body composition using DEXA densitometry in 65 patients (45 females and 20 males) who had been in peritoneal dialysis for a mean of 40.3 +/- 23.2 months. Forty-eight patients (73.8%) had been previously in hemodialysis. The mean total time in dialysis for these patients was 76.8 months. As a group patients showed a very significant positive correlation between TBMC and weight, height, and lean body mass. A negative correlation was found between TBMC with the time in dialysis and iPTH. In men we found significant simple positive correlations between TBMC and weight, height and lean body mass. In women we found simple positive correlations of TBMC with weight, height and lean body mass and a negative correlation with iPTH. In the multiple regression analysis, lean body mass was the only body composition parameter that had a significantly positive correlation with TBMC in men; in women only height correlated positively with TBMC and iPTH continued to correlate negatively with bone mass. When we considered pre and postmenopausal women separately, bone mass was correlated positively with height and lean body mass and negatively with iPTH in postmenopausal women and only with height in pre-menopausal females. We conclude that the lean body mass compartment. is the most important component of weight that determines TBMC in peritoneal dialysis patients particularly in males and postmenopausal women. In postmenopausal women, secondary hyperparathyroidism seems to be particularly detrimental on bone mass.

Adequacy and nutrition in the absence of residual renal function in peritoneal dialysis.

With the aim of evaluating nutrition indices and dialysis adequacy level in patients who started peritoneal dialysis (PD) without residual renal function, we retrospectively studied 19 patients [8 men, 11 women; 3 with diabetes (15.8%); mean age: 44.5 +/- 10.74 years; 15 on continuous ambulatory peritoneal dialysis (CAPD), 3 on continuous cycling peritoneal dialysis (CCPD), 1 on nightly intermittent peritoneal dialysis (NIPD)]. The mean time spent by these patients on hemodialysis before PD was 62.7 +/- 54.7 months (range: 8.8-216 months), and the mean time on PD was 46.2 +/- 21.4 months (range: 10-75 months). In these patients, we measured weekly Kt/V urea, weekly creatinine clearance (CrC), normalized protein catabolic rate (nPCR), body surface area (BSA), urea distribution volume (V), serum albumin, body mass index (BMI), percent lean body mass (%LBM), infusion volume (liters per day), subjective global assessment (SGA), and peritoneal equilibration test (PET). Using the Student t-test at a significance level of p < 0.05, we compared initial body weight (INW), actual weight (AW), and ideal body weight (IBW) according to age, sex, and height. We analyzed actuarial and technique survival (Kaplan-Meier). In regard to patient survival, only death was considered the end point; for technique survival, only technique failure was considered the end point. Data are expressed as mean +/- standard deviation. Results were: Kt/V, 2.20 +/- 0.46 L weekly; CrC, 59.11 +/- 12 L weekly; nPCR, 1.08 +/- 0.25 g/kg daily; BSA, 1.67 +/- 0.2 m2; V, 33.34 +/- 7.12; serum albumin, 3.68 +/- 0.22 g/dL; BMI, 24.06 +/- 4.16; %LBM, 64.92 +/- 10.13; SGA, 94.7% well-nourished; AW, 65.37 +/- 13.88 kg; IBW, 67.21 +/- 10.5 kg (AW vs IBW: r = 0.69, p > 0.05); INW, 61.54 +/- 11.07 kg (INW vs AW: r = 0.92, p < 0.05; INW vs IBW: r = 0.71, p < 0.05). Distribution of transport status by PET was 15.8% high transport, 36.8% high-average transport, 36.8% low-average transport, and 10.5% low transport. Mean infusion volume was 10.41 +/- 1.36 L in 24 hours. Cumulative survival was 100%, 98%, and 82% after 1, 2, and 6 years respectively. Technique survival was 100% after 6 years. The adequacy results accord with Dialysis Outcomes Quality Initiative (DOQI) recommendations, and the nutrition indices and actuarial and technique survival are satisfactory for anuric patients.

Treatment of recurrent and resistant CAPD peritonitis by temporary withdrawal of peritoneal dialysis without removal of the catheter.

Recurrent and resistant continuous ambulatory peritoneal dialysis (CAPD) peritonitis is usually treated by removal of the catheter and temporary hemodialysis. We treated 3 patients: 1 with resistant Klebsiella peritonitis and 2 with recurrent peritonitis (one due to Staphylococcus and the other to Enterococcus), by stopping CAPD for a 2-4 week period, leaving the catheter in situ and continuing antibiotic therapy. All 3 patients had resolution of their infections and restarted CAPD. This therapeutic modality reduced catheter replacements, limited admissions to the hospital, reduced psychological impact, and diminished risks and costs of CAPD.

Protein restriction and progression of chronic renal failure.

The effect of protein restriction upon the rate of renal functional decline was studied in 7 patients with moderate chronic renal failure (CRF). The rate of progression of CRF was evaluated by the reciprocal of plasma creatinine concentration (1/Cr) in time method, every 1-3 months, during 12 months while on ad-libitum diet and 23-40 months thereafter while on protein restriction. While on ad-libitum diet, 4/7 patients showed a progressive disease and the other 3 showed a relatively stable evolution. Six months after protein restriction, patients with a previous progressive disease showed an amelioration in the decline in renal function, and those with stable CRF showed a worsening of the disease in two cases and an improvement in the other one. During the first six months on low protein diet, a transitory increase in plasma creatinine concentration was observed, being maximum at 2.7 months. Plasma urea concentration fell, after protein restriction, to values close to that predicted at the time of the prescription of the diet. Mean systolic and diastolic arterial blood pressure remained stable throughout the study and it was not necessary to change the pharmacological treatment. Our data show that protein restriction decreases the rate of progression of CRF in patients with previous progressive disease. This benefit may result from the suppression of compensatory hyperfiltration induced by low protein diet, as suggested by the increase in plasma creatinine concentration.

Protein restriction and progression of chronic renal failure

La insuficiencia renal crónica (RC) una vez establecida, progresa inoxeroblemente hacia el estadio terminal, determinando la supresión total de la función renal. El enlentecimiento de la velocidad de progresión de la enfermedad es por lo tanto, uno de los objetos más importantes de la nefrología actual. La restricción proteica ha sido la estrategia terapéutica más utilizada para este fin, observándose modificacions de las alteraciones hemodinámicas intraglomerulares a nivel experimental y enlentecimiento de la velocidad de progresión en la mayoría de los pacientes. Por ese motivo estudiamos el efecto de la restricción proteica sobre la velocidad de progresión en 7 pacientes con Cr plasmáticas entre 2,74-5,3 mg/dl, cuyos datos clínicos figuran en la Tabla 1. La velocidad de progresión se evaluó por el método de la 1/CR cada 1-3 meses durante 1 año de ingesta proteica adlibitum y durante 23-40 meses de restricción proteica. La ingesta proteica indicada, fue individualmente calculada considerando el requerimiento proteico basal y la capacidad renal para excretar urea (Tabla 2). La ingesta proteica observada durante el período de restricción proteica, fue significativamente menor que la ingesta ad-libitum aunque superior a la indicada (Fig. 1). El curso de la enfermedad (Fi. 2) mostró durante el año de ingesta ad-libitum, enfermedad progresiva en 4/7 pacientes (panel izquierdo), siendo relativamente estable en los 3 restantes (panel derecho). Despues de seis meses de iniciada la restricción proteica, los pacientes con enfermedad progresiva previa mostraron un enlentecimiento de su velocidad de progresión, ya que las determinaciones de 1/Cr reales de este período, se ubicaron por encima de las correspondientes a la evolución natural de la enfermedad. Los pacientes con enfermedad relativamente estable, mostraron durante el tratamiento, una aceleración de la velocidad de progresión en 2 casos y una mejoría en el restante. Durante los primeros 6 meses de restricción proteica (Fig. 3), se observó un aumento transitorio de la Cr plasmática que fue máximo a los 2,7 meses y una disminución de la ureia plasmática que a los 1,5 meses alcanzó un valor cercano al estimado al prescribir la dieta (Tabla 2). La excreción media de creatinina (1118 + 25 mg/día1,73 m**2 SC) se mantuvo estable a lo largo de todo el estudio. Las cifras de presión arterial sistólica y diastólica no mostraron cambios significativos entre el período de ingesta ad-libitum y el de restricción proteica

Protein restriction and progression of chronic renal failure.

The effect of protein restriction upon the rate of renal functional decline was studied in 7 patients with moderate chronic renal failure (CRF). The rate of progression of CRF was evaluated by the reciprocal of plasma creatinine concentration (1/Cr) in time method, every 1-3 months, during 12 months while on ad-libitum diet and 23-40 months thereafter while on protein restriction. While on ad-libitum diet, 4/7 patients showed a progressive disease and the other 3 showed a relatively stable evolution. Six months after protein restriction, patients with a previous progressive disease showed an amelioration in the decline in renal function, and those with stable CRF showed a worsening of the disease in two cases and an improvement in the other one. During the first six months on low protein diet, a transitory increase in plasma creatinine concentration was observed, being maximum at 2.7 months. Plasma urea concentration fell, after protein restriction, to values close to that predicted at the time of the prescription of the diet. Mean systolic and diastolic arterial blood pressure remained stable throughout the study and it was not necessary to change the pharmacological treatment. Our data show that protein restriction decreases the rate of progression of CRF in patients with previous progressive disease. This benefit may result from the suppression of compensatory hyperfiltration induced by low protein diet, as suggested by the increase in plasma creatinine concentration.

Protein restriction and progression of chronic renal failure.

The effect of protein restriction upon the rate of renal functional decline was studied in 7 patients with moderate chronic renal failure (CRF). The rate of progression of CRF was evaluated by the reciprocal of plasma creatinine concentration (1/Cr) in time method, every 1-3 months, during 12 months while on ad-libitum diet and 23-40 months thereafter while on protein restriction. While on ad-libitum diet, 4/7 patients showed a progressive disease and the other 3 showed a relatively stable evolution. Six months after protein restriction, patients with a previous progressive disease showed an amelioration in the decline in renal function, and those with stable CRF showed a worsening of the disease in two cases and an improvement in the other one. During the first six months on low protein diet, a transitory increase in plasma creatinine concentration was observed, being maximum at 2.7 months. Plasma urea concentration fell, after protein restriction, to values close to that predicted at the time of the prescription of the diet. Mean systolic and diastolic arterial blood pressure remained stable throughout the study and it was not necessary to change the pharmacological treatment. Our data show that protein restriction decreases the rate of progression of CRF in patients with previous progressive disease. This benefit may result from the suppression of compensatory hyperfiltration induced by low protein diet, as suggested by the increase in plasma creatinine concentration.

Protein restriction and progression of chronic renal failure

La insuficiencia renal crónica (RC) una vez establecida, progresa inoxeroblemente hacia el estadio terminal, determinando la supresión total de la función renal. El enlentecimiento de la velocidad de progresión de la enfermedad es por lo tanto, uno de los objetos más importantes de la nefrología actual. La restricción proteica ha sido la estrategia terapéutica más utilizada para este fin, observándose modificacions de las alteraciones hemodinámicas intraglomerulares a nivel experimental y enlentecimiento de la velocidad de progresión en la mayoría de los pacientes. Por ese motivo estudiamos el efecto de la restricción proteica sobre la velocidad de progresión en 7 pacientes con Cr plasmáticas entre 2,74-5,3 mg/dl, cuyos datos clínicos figuran en la Tabla 1. La velocidad de progresión se evaluó por el método de la 1/CR cada 1-3 meses durante 1 año de ingesta proteica adlibitum y durante 23-40 meses de restricción proteica. La ingesta proteica indicada, fue individualmente calculada considerando el requerimiento proteico basal y la capacidad renal para excretar urea (Tabla 2). La ingesta proteica observada durante el período de restricción proteica, fue significativamente menor que la ingesta ad-libitum aunque superior a la indicada (Fig. 1). El curso de la enfermedad (Fi. 2) mostró durante el año de ingesta ad-libitum, enfermedad progresiva en 4/7 pacientes (panel izquierdo), siendo relativamente estable en los 3 restantes (panel derecho). Despues de seis meses de iniciada la restricción proteica, los pacientes con enfermedad progresiva previa mostraron un enlentecimiento de su velocidad de progresión, ya que las determinaciones de 1/Cr reales de este período, se ubicaron por encima de las correspondientes a la evolución natural de la enfermedad. Los pacientes con enfermedad relativamente estable, mostraron durante el tratamiento, una aceleración de la velocidad de progresión en 2 casos y una mejoría en el restante. Durante los primeros 6 meses de restricción proteica (Fig. 3), se observó un aumento transitorio de la Cr plasmática que fue máximo a los 2,7 meses y una disminución de la ureia plasmática que a los 1,5 meses alcanzó un valor cercano al estimado al prescribir la dieta (Tabla 2). La excreción media de creatinina (1118 + 25 mg/día1,73 m**2 SC) se mantuvo estable a lo largo de todo el estudio. Las cifras de presión arterial sistólica y diastólica no mostraron cambios significativos entre el período de ingesta ad-libitum y el de restricción proteica