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Background: Hemodialysis patients with mineral and bone disorders (MBDs) have an abnormally high relative risk of death, but their absolute risk of death is unknown. Further, previous studies have not accounted for possible time-dependent confounding of the association between MBD markers and death due to the effect of markers of MBD on treatments, which subsequently may affect MBD markers., Study Design: Multicenter, 3-year, prospective, case-cohort study., Setting & Participants: 8,229 hemodialysis patients with secondary hyperparathyroidism (parathyroid hormone level ≥180 pg/mL and/or receiving vitamin D receptor activators) at 86 facilities in Japan., Predictors: Serum phosphorus, calcium, and parathyroid hormone levels., Outcome: All-cause mortality., Measurements: Marginal structural models were used to compute absolute differences in all-cause mortality associated with different levels of predictors while accounting for time-dependent confounding., Results: The association between phosphorus level and mortality appeared U-shaped, although only higher phosphorus level categories reached statistical significance: compared to those with phosphorus levels of 5.0-5.9 mg/dL (1.61-1.93 mmol/L), patients with the highest (≥9.0 mg/dL [≥2.90 mmol/L]) phosphorus levels had 9.4 excess deaths/100 person-years (rate ratio, 2.79 [95% CI, 1.26-6.15]), whereas no association was found for the lowest phosphorus category (<3.0 mg/dL [<0.97 mmol/L]; rate ratio, 1.54 [95% CI, 0.87-2.71]). Similarly, hypercalcemia (≥10.0 mg/dL [≥2.50 mmol/L]) was associated with excess deaths, and the highest level of hypercalcemia (≥11.0 mg/dL [≥2.75 mmol/L]) was associated with 5.8 excess deaths/100 person-years (rate ratio, 2.38 [95% CI, 1.77-3.21]) compared to those with levels of 9.0-9.4 mg/dL (2.25-2.37 mmol/L). Abnormally high parathyroid hormone levels were not associated with excess deaths., Limitations: Possible residual confounding., Conclusions: These results reinforce the idea that serum calcium (in addition to phosphorus) level is an important predictor of the absolute risk of death in hemodialysis patients with secondary hyperparathyroidism., (Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Children with end-stage renal disease (ESRD) receiving hemodialysis may have their care overseen primarily by a pediatric nephrologist or internal medicine (IM) nephrologist., Methods: To examine specific clinical outcomes by nephrologist specialization, a cross-sectional analysis of demographic and clinical data collected in the 2002 ESRD Clinical Performance Measures Project was performed., Results: Of 653 pediatric patients meeting inclusion criteria, 27% were cared for by IM nephrologists, and 73%, by pediatric nephrologists. Pediatric nephrologists were significantly more likely than IM nephrologists to care for patients who were younger and of Hispanic ethnicity. Patients of pediatric compared with IM nephrologists also were more likely to have a congenital cause of ESRD, smaller body mass index, and longer time on dialysis therapy. No significant differences in achieving a mean Kt/V of 1.2 or greater or mean hemoglobin level of 11 g/dL or greater (> or =110 g/L) according to nephrologist specialization were observed. After adjustment for patient clinical characteristics, no significant difference in use of arteriovenous fistulae was observed. Patients cared for by pediatric nephrologists were less likely to achieve a mean serum albumin level of 4.0/3.7 g/dL (40/37 g/L; bromcresol green laboratory method/bromcresol purple laboratory method; adjusted odds ratio, 0.60; 95% confidence interval, 0.42 to 0.86). Patients cared for by pediatric nephrologists had significantly greater serum calcium levels, lower serum phosphate levels, and lower intact parathyroid hormone levels., Conclusion: Using adult-focused clinical care targets, care provided by pediatric and IM nephrologists to pediatric patients receiving hemodialysis in the United States is similar. However, differences exist, and the significance of these differences requires further study.

Renal osteodystrophy therapy in dialysis patients with calcitriol and intestinal phosphate binders containing calcium entails the risk of hypercalcemia. A study was performed using 35 hemodialysis patients to see whether the time of day when calcitriol is administered influences the incidence of hypercalcemia. It was shown that simply by administering at night (11:00 PM), the occurrence of hypercalcemia was significantly reduced. While greater than 80% of patients developed hypercalcemia when calcitriol was administered in the morning, when administered at night, this figure was only 50% (P less than 0.013). At the same time, the extent of hypercalcemia when calcitriol was administered at night was significantly lower than when it was administered in the morning. The incidence of hypercalcemia occurred regardless of the type of phosphate binder containing calcium used, whether it was calcium acetate or calcium carbonate. In addition, hypercalcemic episodes were always associated with hyperphosphatemia. On the basis of the above information, it would be expedient to administer calcitriol at night to dialysis patients, in order to reduce the risk of hypercalcemia and to preserve the hypophosphatemic effect of the applied intestinal phosphate binders.