Article

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: 6.59). 12/2010; 25(12):2724-34. DOI: 10.1002/jbmr.177
Source: PubMed

ABSTRACT 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

Full-text

Available from: Kamyar Kalantar-Zadeh, Jun 30, 2015
0 Followers
 · 
183 Views
  • 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
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The outcome-predictability of baseline and instantaneously changing serum calcium in hemodialysis patients has been examined. We investigated the mortality-predictability of time-averaged calcium values to reflect the 'cumulative' effect of calcium burden over time. We employed a Cox model using up-to-5-year (7/2001-6/2006) time-averaged values to examine the mortality-predictability of cumulative serum calcium levels in 107,200 hemodialysis patients prior to the use of calcimimetics, but during the time where other calcium-lowering interventions, including lower dialysate calcium, were employed. Both low (<9.0 mg/dl) and high (>10.0 mg/dl) calcium levels were associated with increased mortality (reference: 9.0 to <9.5 mg/dl). Whereas mortality of hypercalcemia was consistent, hypocalcemia mortality was most prominent with higher serum phosphorus (>3.5 mg/dl) and PTH levels (>150 pg/ml). Higher paricalcitol doses shifted the calcium range associated with the greatest survival to the right, i.e. from 9.0 to <9.5 to 9.5 to <10.0 mg/dl. African-Americans exhibited the highest death hazard ratio of hypocalcemia <8.5 mg/dl, being 1.35 (95% CI: 1.22-1.49). Both a rise and drop in serum calcium over 6 months were associated with increased mortality compared to the stable group. Whereas in hemodialysis patients cumulatively high or low calcium levels are associated with higher death risk, subtle but meaningful interactions with phosphorus, PTH, paricalcitol dose and race exist.
    American Journal of Nephrology 01/2010; 32(5):403-13. DOI:10.1159/000319861
  • [Show abstract] [Hide abstract]
    ABSTRACT: There are counterintuitive but consistent observations that African American maintenance dialysis patients have greater survival despite their less favorable socioeconomic status, high burden of cardiovascular risks including hypertension and diabetes, and excessively high chronic kidney disease prevalence. The fact that such individuals have a number of risk factors for lower survival and yet live longer when undergoing dialysis treatment is puzzling. Similar findings have been made among Israeli maintenance dialysis patients, in that those who are ethnically Arab have higher end-stage renal disease but exhibit greater survival than Jewish Israelis. The juxtaposition of these two situations may provide valuable insights into racial/ethnic-based mechanisms of survival in chronic diseases. Survival advantages of African American dialysis patients may be explained by differences in nutritional status, inflammatory profile, dietary intake habits, body composition, bone and mineral disorders, mental health and coping status, dialysis treatment differences, and genetic differences among other factors. Prospective studies are needed to examine similar models in other countries and to investigate the potential causes of these paradoxes in these societies. Better understanding the roots of racial/ethnic survival differences may help improve outcomes in both patients with chronic kidney disease and other individuals with chronic disease states.
    Seminars in Dialysis 11/2010; 23(6):586-94. DOI:10.1111/j.1525-139X.2010.00795.x