TY - JOUR
T1 - Changes in serum calcium, phosphate, and PTH and the risk of death in incident dialysis patients
T2 - A longitudinal study
AU - Melamed, M. L.
AU - Eustace, J. A.
AU - Plantinga, L.
AU - Jaar, B. G.
AU - Fink, N. E.
AU - Coresh, J.
AU - Klag, M. J.
AU - Powe, N. R.
N1 - Funding Information:
This work was supported by Grant No. R01DK59616 from the National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA; Grant No. R01HS08365 from the Agency for Health Care Research and Quality, Rockville, MD, USA; and Grant No. R01HL62985 from the National Heart Lung and Blood Institute, Bethesda, MD, USA. MLM is supported by Grant No. F32 DK069017, MJK is supported by Grant No. K24DK02856, and NRP is supported by Grant No. K24DK02643 from the National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA. This study was presented, in part, at the 2004 American Society of Nephrology Annual Meeting in St Louis, MO, USA. Some of the data reported here have been supplied by the United States Renal Data System. The interpretation and reporting of these data are the responsibility of the authors and in no way should be seen as an official policy or interpretation of the US government. We thank the patients, staff, and medical directors of the participating clinics who contributed to the study.
PY - 2006/7/7
Y1 - 2006/7/7
N2 - Elevated bone mineral parameters have been associated with mortality in dialysis patients. There are conflicting data about calcium, parathyroid hormone (PTH), and mortality and few data about changes in bone mineral parameters over time. We conducted a prospective cohort study of 1007 incident hemodialysis and peritoneal dialysis patients. We examined longitudinal changes in bone mineral parameters and whether their associations with mortality were independent of time on dialysis, inflammation, and comorbidity. Serum calcium, phosphate, and calcium-phosphate product (CaP) increased in these patients between baseline and 6 months (P<0.001) and then remained stable. Serum PTH decreased over the first year (P<0.001). In Cox proportional hazards models adjusting for inflammation, comorbidity, and other confounders, the highest quartile of phosphate was associated with a hazard ratio (HR) of 1.57 (1.07-2.30) using both baseline and time-dependent values. The highest quartiles of calcium, CaP, and PTH were associated with mortality in time-dependent models but not in those using baseline values. The lowest quartile of PTH was associated with an HR of 0.65 (0.44-0.98) in the time-dependent model with 6-month lag analysis. We conclude that high levels of phosphate both at baseline and over follow-up are associated with mortality in incident dialysis patients. High levels of calcium, CaP, and PTH are associated with mortality immediately preceding an event. Promising new interventions need to be rigorously tested in clinical trials for their ability to achieve normalization of bone mineral parameters and reduce deaths of dialysis patients.
AB - Elevated bone mineral parameters have been associated with mortality in dialysis patients. There are conflicting data about calcium, parathyroid hormone (PTH), and mortality and few data about changes in bone mineral parameters over time. We conducted a prospective cohort study of 1007 incident hemodialysis and peritoneal dialysis patients. We examined longitudinal changes in bone mineral parameters and whether their associations with mortality were independent of time on dialysis, inflammation, and comorbidity. Serum calcium, phosphate, and calcium-phosphate product (CaP) increased in these patients between baseline and 6 months (P<0.001) and then remained stable. Serum PTH decreased over the first year (P<0.001). In Cox proportional hazards models adjusting for inflammation, comorbidity, and other confounders, the highest quartile of phosphate was associated with a hazard ratio (HR) of 1.57 (1.07-2.30) using both baseline and time-dependent values. The highest quartiles of calcium, CaP, and PTH were associated with mortality in time-dependent models but not in those using baseline values. The lowest quartile of PTH was associated with an HR of 0.65 (0.44-0.98) in the time-dependent model with 6-month lag analysis. We conclude that high levels of phosphate both at baseline and over follow-up are associated with mortality in incident dialysis patients. High levels of calcium, CaP, and PTH are associated with mortality immediately preceding an event. Promising new interventions need to be rigorously tested in clinical trials for their ability to achieve normalization of bone mineral parameters and reduce deaths of dialysis patients.
KW - Clinical epidemiology
KW - Dialysis
KW - Epidemiology and outcomes
KW - Hospitalization
KW - Mortality risk
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U2 - 10.1038/sj.ki.5001542
DO - 10.1038/sj.ki.5001542
M3 - Article
C2 - 16738536
AN - SCOPUS:33746176065
SN - 0085-2538
VL - 70
SP - 351
EP - 357
JO - Kidney international
JF - Kidney international
IS - 2
ER -