title: Effect Modifying Role of Serum Calcium on Mortality-Predictability of PTH and Alkaline Phosphatase in Hemodialysis Patients: An Investigation Using Data from the Taiwan Renal Registry Data System from 2005 to 2012.
abstract: Predicting mortality in dialysis patients based on low intact parathyroid hormone levels is difficult, because aluminum intoxication, malnutrition, older age, race, diabetes, or peritoneal dialysis may influence these levels. We investigated the clinical implications of low parathyroid hormone levels in relation to the mortality of dialysis patients using sensitive, stratified, and adjusted models and a nationwide dialysis database. We analyzed data from 2005 to 2012 that were held on the Taiwan Renal Registry Data System, and 94,983 hemodialysis patients with valid data regarding their intact parathyroid levels were included in this study. The patient cohort was subdivided based on the intact parathyroid hormone and alkaline phosphatase levels. The mean hemodialysis duration within this cohort was 3.5 years. The mean (standard deviation) age was 62 (14) years. After adjusting for age, sex, diabetes, the hemodialysis duration, serum albumin levels, hematocrit levels, calcium levels, phosphate levels, and the hemodialysis treatment adequacy score, the single-pool Kt/V, the crude and adjusted all-cause mortality rates increased when alkaline phosphatase levels were higher or intact parathyroid hormone levels were lower. In general, at any given level of serum calcium or phosphate, patients with low intact parathyroid hormone levels had higher mortality rates than those with normal or high iPTH levels. At a given alkaline phosphatase level, the hazard ratio for all-cause mortality was 1.33 (p < 0.01, 95% confidence interval 1.27-1.39) in the group with intact parathyroid hormone levels < 150 pg/mL and serum calcium levels > 9.5 mg/dL, but in the group with intact parathyroid hormone levels > 300 pg/mL and serum calcium levels > 9.5 mg/dL, the hazard ratio was 0.92 (95% confidence interval 0.85-1.01). Hence, maintaining albumin-corrected high serum calcium levels at > 9.5 mg/dL may correlate with poor prognoses for patients with low intact parathyroid hormone levels.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yen-Chung
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Division of Endocrinology & Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Chiao-Ying
authors.initials: CY
authors.lastname: Hsu
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Chih-Chin
authors.initials: CC
authors.lastname: Kao
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Fan-Chi
authors.initials: FC
authors.lastname: Chang
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Tzen-Wen
authors.initials: TW
authors.lastname: Chen
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Hsi-Hsien
authors.initials: HH
authors.lastname: Chen
authors.affiliation: Center for Health Policy Research and Development, National Health Research Institutes, Miaoli, County, Taiwan.
authors.forename: Chi-Cheng
authors.initials: CC
authors.lastname: Hsu
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Mai-Szu
authors.initials: MS
authors.lastname: Wu
mesh_terms: D000368:Aged; D000418:Albumins / Q000032:analysis; D000469:Alkaline Phosphatase / Q000097:blood*; D002118:Calcium / Q000097:blood*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D010530:Peritoneal Dialysis; D010710:Phosphates / Q000097:blood; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D006435:Renal Dialysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013624:Taiwan
chemical_list: D000418:Albumins; D010281:Parathyroid Hormone; D010710:Phosphates; D000469:Alkaline Phosphatase; D002118:Calcium