Magnitude and impact of abnormal mineral metabolism in hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS).
BACKGROUND
Mineral metabolism has emerged as an important predictor of morbidity and mortality in dialysis patients, independent of bone and muscle concerns. Several expert panels have issued management guidelines for mineral metabolism.


METHODS
The state of mineral metabolism (serum parathyroid hormone [PTH], phosphorus, calcium, and calcium-phosphorus product) was described for representative samples of patients and facilities from 7 countries (France, Germany, Italy, Japan, Spain, United Kingdom, and United States) participating in the Dialysis Outcomes and Practice Patterns Study (DOPPS I, 1996-2001; DOPPS II, 2002-2004).


RESULTS
A relatively modest percentage of patients fell within the guideline range for PTH (21.4% in DOPPS I, 26.2% in DOPPS II), serum phosphorus (40.8%, 44.4%), albumin-corrected serum calcium (40.5%, 42.5%), and calcium-phosphorus product (56.6%, 61.4%). Results were not dramatically different across countries. The majority of patients not within guideline ranges had high serum levels of phosphorus (51.6% in DOPPS I, 46.7% in DOPPS II), calcium (50.1%, 48.6%), and calcium-phosphorus product (43.4%, 38.6%) and low (<150 pg/mL) concentrations of PTH (52.9%, 47.5%). It was rare for patients to fall within recommended ranges for all indicators of mineral metabolism; 23% to 28% fell within guideline for at least 3 measures and only 4.6% to 5.5% of patients were within range for all 4. The risks of all-cause and cardiovascular mortality were directly and independently associated with each of the 4 indicators.


CONCLUSIONS
The DOPPS provides a useful comparison benchmark for the state of mineral metabolism management of patients with kidney disease; it also affirms the association between mineral metabolism and important patient outcomes.
University of Michigan/Veterans Administration Medical Center, Ann Arbor, MI 48105, USA. dopps@urrea.org
Eric W
EW
Young
Takashi
T
Akiba
Justin M
JM
Albert
James T
JT
McCarthy
Peter G
PG
Kerr
David C
DC
Mendelssohn
Michel
M
Jadoul
D002118:Calcium / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy; D008903:Minerals / Q000378:metabolism*; D009017:Morbidity; D017063:Outcome Assessment, Health Care; D010281:Parathyroid Hormone / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D006435:Renal Dialysis
D008903:Minerals; D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium