Impact of Race on Hyperparathyroidism, Mineral Disarrays, Administered Vitamin D Mimetic, and Survival in Hemodialysis Patients

Harold Simmons Center for Chronic Disease Research and Epidemiology, Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Torrance, CA, USA.
Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research (Impact Factor: 6.83). 12/2010; 25(12):2724-34. DOI: 10.1002/jbmr.177
Source: PubMed


Blacks have high rates of chronic kidney disease, are overrepresented among the US dialysis patients, have higher parathyroid hormone levels, but greater survival compared to nonblacks. We hypothesized that mineral and bone disorders (MBDs) have a bearing on survival advantages of black hemodialysis patients. In 139,328 thrice-weekly treated hemodialysis patients, including 32% blacks, in a large dialysis organization, where most laboratory values were measured monthly for up to 60 months (July 2001 to June 2006), we examined differences across races in measures of MBDs and survival predictabilities of these markers and administered the active vitamin D medication paricalcitol. Across each age increment, blacks had higher serum calcium and parathyroid hormone (PTH) levels and almost the same serum phosphorus and alkaline phosphatase levels and were more likely to receive injectable active vitamin D in the dialysis clinic, mostly paricalcitol, at higher doses than nonblacks. Racial differences existed in mortality predictabilities of different ranges of serum calcium, phosphorus, and PTH but not alkaline phosphatase. Blacks who received the highest dose of paricalcitol (>10 µg/week) had a demonstrable survival advantage over nonblacks (case-mix-adjusted death hazard ratio = 0.87, 95% confidence level 0.83-0.91) compared with those who received lower doses (<10 µg/week) or no active vitamin D. Hence, in black hemodialysis patients, hyperparathyroidism and hypercalcemia are more prevalent than in nonblacks, whereas hyperphosphatemia or hyperphosphatasemia are not. Survival advantages of blacks appear restricted to those receiving higher doses of active vitamin D. Examining the effect of MBD modulation on racial survival disparities of hemodialysis patients is warranted.

Download full-text


Available from: Kamyar Kalantar-Zadeh, Oct 09, 2015
13 Reads
  • Source
    • "Therapy with vitamin D receptor (VDR) activators, including calcitriol or the selective VDR activator paricalcitol [4, 10–12], has been associated with improved survival in patients with CKD on haemodialysis [13–16]. Evidence from epidemiological studies further suggests that the causes for the survival benefit from VDR activator therapy go beyond the control of iPTH and calcium–phosphorus homoeostasis [10, 11, 13]. Consequently, VDR activators, including paricalcitol [17], have become a commonly used therapy in patients with SHPT on dialysis. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Optimal treatment for secondary hyperparathyroidism (SHPT) has not been defined. The IMPACT SHPT ( identifier: NCT00977080) study assessed whether dose-titrated paricalcitol plus supplemental cinacalcet only for hypercalcaemia is superior to cinacalcet plus low-dose vitamin D in controlling intact parathyroid hormone (iPTH) levels in patients with SHPT on haemodialysis. In this 28-week, multicentre, open-label Phase 4 study, participants were randomly selected to receive paricalcitol or cinacalcet plus low-dose vitamin D. Randomization and analyses were stratified by mode of paricalcitol administration [intravenous (IV) or oral]. The primary efficacy end point was the proportion of subjects who achieved a mean iPTH value of 150-300 pg/mL during Weeks 21-28. Of 272 subjects randomized, 268 received one or more dose of study drug; 101 in the IV and 110 in the oral stratum with two or more values during Weeks 21-28 were included in the primary analysis. In the IV stratum, 57.7% of subjects in the paricalcitol versus 32.7% in the cinacalcet group (P = 0.016) achieved the primary end point. In the oral stratum, the corresponding proportions of subjects were 54.4% for paricalcitol and 43.4% for cinacalcet (P = 0.260). Cochran-Mantel-Haenszel analysis, controlling for stratum, revealed overall superiority of paricalcitol (56.0%) over cinacalcet (38.2%; P = 0.010) in achieving iPTH 150-300 pg/mL during Weeks 21-28. Hypercalcaemia occurred in 4 (7.7%) and 0 (0%) of paricalcitol-treated subjects in the IV and oral strata, respectively. Hypocalcaemia occurred in 46.9% and 54.7% of cinacalcet-treated subjects in the IV and oral strata, respectively. Paricalcitol versus cinacalcet plus low-dose vitamin D provided superior control of iPTH, with low incidence of hypercalcaemia.
    Nephrology Dialysis Transplantation 03/2012; 27(8):3270-8. DOI:10.1093/ndt/gfs018 · 3.58 Impact Factor
  • Source
    • "Regarding secondary hyperparathyroidism, there are significant differences in the progression of the disease between patients of different ethnicities: while black patients require higher vitamin D doses than non-blacks [21], Asian patients show slower progression of the disease than non-Asians with the same stages of renal insufficiency [22]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Although parathyroidectomy remains the only curative approach to most primary hyperparathyroidism cases, medical treatment with cinacalcet HCl has been proven to be a reasonable alternative for several patient subgroups. Cinacalcet almost always controls hypercalcemia and hypophosphatemia sufficiently. PTH levels are lowered, and cognitive parameters improve. While an increase in bone mineral density DEXA scan scores was not demonstrated in cinacalcet trials, the same applies to more than half of patients after parathyroidectomy. Medical therapy should be first choice in patients with hyperplasia in all glands rather than an isolated adenoma (10-15%), patients with persisting HPT following unsuccessful surgery or inoperable cases due to comorbidities, and patients detected in lab screens for hypercalcemia before developing symptoms who should be treated early but are usually reluctant to undergo surgery. Nephrolithiasis was not found to occur more frequently in cinacalcet trial groups, but urine calcium excretion as one major risk factor of this complication of primary HPT may increase on cinacalcet. Patients carrying the rs1042636 polymorphism of the calcium-sensing receptor gene respond more sensitively to cinacalcet and have a higher risk of calcium stone formation. Cinacalcet is usually administered twice daily but three or four doses per day should be discussed to mimic the beneficial pulsatile PTH-pattern.
    International Journal of Endocrinology 03/2011; 2011:415719. DOI:10.1155/2011/415719 · 1.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It was found that wafer charging during processing can cause the quasi-breakdown of gate oxide and lead to more than four orders of magnitude increase in gate leakage current. Gate oxides that have experienced this quasi-breakdown display minimal transistor parameter shifts under constant gate current stress because the stress field sustained across the oxide is low. As a result, large antenna devices, which experience significant wafer charging, have a greater percentage of oxides which have experienced quasi-breakdown and therefore display smaller than expected parameter shifts. To avoid misleading conclusions, an appropriate interpretation of the characterization results is necessary especially for thin gate oxides
    Integrated Reliability Workshop, 1996., IEEE International; 11/1996
Show more