title: Impact of race on hyperparathyroidism, mineral disarrays, administered vitamin D mimetic, and survival in hemodialysis patients.
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.
authors.affiliation: Harold Simmons Center for Chronic Disease Research and Epidemiology, Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Torrance, CA, USA. kamkal@ucla.edu
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Miller
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.forename: Rajnish
authors.initials: R
authors.lastname: Mehrotra
authors.forename: Lilia R
authors.initials: LR
authors.lastname: Lukowsky
authors.forename: Elani
authors.initials: E
authors.lastname: Streja
authors.forename: Joni
authors.initials: J
authors.lastname: Ricks
authors.forename: Jennie
authors.initials: J
authors.lastname: Jing
authors.forename: Allen R
authors.initials: AR
authors.lastname: Nissenson
authors.forename: Sander
authors.initials: S
authors.lastname: Greenland
authors.forename: Keith C
authors.initials: KC
authors.lastname: Norris
mesh_terms: D000328:Adult; D001741:Black or African American / Q000208:ethnology*; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood; D003710:Demography; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000208:ethnology* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D016017:Odds Ratio; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000009:adverse effects*; D016019:Survival Analysis; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D055815:Young Adult
chemical_list: D008903:Minerals; D010281:Parathyroid Hormone; D014807:Vitamin D; D010758:Phosphorus; D002118:Calcium