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: 6.04). 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.

0 Bookmarks
 · 
153 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Compared with Caucasians, African Americans have lower circulating concentrations of 25-hydroxyvitamin D (25(OH)D), the major storage form of vitamin D, leading to the widespread assumption that African Americans are at higher risk of vitamin D deficiency. However, the finding that African Americans maintain better indices of musculoskeletal health than Caucasians throughout their lifespan despite having lower circulating 25(OH)D concentrations suggests that the relationship between vitamin D deficiency and racial health disparities may not be so straightforward. The fairly recent emergence of fibroblast growth factor 23 (FGF23) may help resolve some of this uncertainty. FGF23 strongly modulates both systemic and local activation of 25(OH)D, playing a potentially important role in the degree to which lower 25(OH)D concentrations impact health outcomes, including differences in the incidence and rate of progression of chronic kidney disease by race. This review critically assesses ongoing controversies surrounding the relationship between vitamin D and racial disparities in chronic kidney disease outcomes, and how FGF23 may help to clarify the picture.
    Seminars in Nephrology 09/2013; 33(5):448-456. · 2.83 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In patients undergoing maintenance hemodialysis (MHD), increasing numbers of studies have reported a reduced mortality in patients with an increased body mass index (BMI). This article provides a meta-analysis on the assessment of the relationship between BMI and mortality in MHD patients. A systemic literature review was conducted to identify studies that examined all-cause mortality, with or without cardiovascular events, on the basis of bodyweight or obesity measures in MHD population published before October 2012. Eight observational studies with a total of 190,163 patients were included. Compared to the individuals with a normal BMI, overweight patients and obese patients were associated with lower all-cause mortality [relative risk (RR) 0.86, 95 % confidence interval (CI) 0.84-0.88; RR 0.77, 95 % CI 0.75-0.78, respectively] and cardiovascular mortality (RR 0.86; 95 % CI 0.81-0.91; RR 0.78, 95 % CI 0.73-0.83, respectively). Underweight patients had relatively higher all-cause and cardiovascular mortality (RR 1.22, 95 % CI 1.20-1.25; RR 1.19, 95 % CI 1.11-1.28, respectively). In an obesity-stratified analysis, the patients with moderate or severe obesity presented a strongly decreased all-cause mortality risk (RR 0.64, 95 % CI 0.61-0.68) and cardiovascular mortality risk (RR 0.63, 95 % CI 0.53-0.75) compared to patients with mild obesity (RR 0.74, 95 % CI 0.71-0.77; RR 0.81, 95 % CI 0.75-0.87, respectively). These findings show that overweight and obese patients have lower all-cause and cardiovascular mortality rates in patients undergoing MHD. Body weight management and optimized nutritional and metabolic support should help to reduce the high mortality rates that are prevalent in the hemodialysis population.
    International Urology and Nephrology 02/2014; · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Anemia is less prominent in patients with polycystic kidney disease (PKD). Such iron indices as ferritin and transferrin saturation (TSAT) values are used to guide management of anemia in individuals on maintenance hemodialysis (MHD). Optimal levels of correction of anemia and optimal levels of TSAT and ferritin are unclear in chronic kidney disease patients and have not been studied specifically in PKD. We studied 2969 MHD patients with and 128 054 patients without PKD from 580 outpatient hemodialysis facilities between July 2001 and June 2006. Using baseline, time-dependent and time-averaged values with unadjusted and multivariable adjusted analysis models, the survival predictabilities of TSAT and ferritin were studied. PKD patients were 58 ± 13 years old and included 46% women, whereas non-PKD patients were 62 ± 15 years old and 45% women. In both PKD and non-PKD patients, a time-averaged TSAT between 30 and 40% was associated with the lowest mortality. Time-averaged ferritin between 100 and <800 ng/mL was associated with the lowest mortality in PKD patients, although this range was 500 to <800 ng/mL in non-PKD patients. In MHD patients with and without PKD, there was a U-shaped relationship between the average TSAT and mortality, and a TSAT of 30-40% was associated with the best survival. However, an average ferritin of 100-800 ng/mL was associated with the best survival in PKD patients, whereas that of non-PKD patients was 500-800 ng/mL. Further studies in PKD and non-PKD patients are necessary to determine whether or not therapeutic attempts to keep TSAT and ferritin levels in these ranges will improve survival.
    Nephrology Dialysis Transplantation 11/2013; 28(11):2889-98. · 3.37 Impact Factor

Full-text (2 Sources)

Download
32 Downloads
Available from
Jun 5, 2014