title: Frequent monitoring of mineral metabolism in hemodialysis patients with secondary hyperparathyroidism: associations with achievement of treatment goals and with adjustments in therapy.
abstract: Dialysis guidelines in Japan recommend more frequent measurement of mineral metabolism markers than the Kidney Disease: Improving Global Outcomes guidelines. However, the extent to which frequent marker measurement contributes to achievement of target ranges and to therapy adjustment is unknown.
  
  
  
  This multicenter cohort study involved 3276 hemodialysis patients with secondary hyperparathyroidism. Data on laboratory measurements and drug prescriptions were collected every 3 months. Main exposures were frequencies of measuring serum calcium and phosphorus [weekly/biweekly/monthly (reference)] and serum parathyroid hormone (PTH) [monthly/bimonthly/trimonthly (reference)] levels. Outcomes were achievement of guideline-specified ranges of mineral metabolism markers when serum levels were over, and maintenance of ranges when levels were already within, respective specified ranges, use of intravenous vitamin D receptor activator (VDRA) and initiation of cinacalcet use. Associations were examined via generalized estimating equations.
  
  
  
  When serum marker levels exceeded the target range, weekly measurement of calcium and phosphorus was positively associated with achievement of the guideline-specified calcium range [adjusted odds ratio (AOR): 1.57, 95% confidence interval (CI) 1.09-2.26] but not phosphorus range (AOR: 0.99, 95% CI 0.74-1.33). Monthly measurement of PTH was positively associated with achievement of the guideline-specified PTH range (AOR: 1.14, 95% CI 1.01-1.27). When serum marker levels were within the guideline-specified range, increased frequency of measurements was not associated with in-range maintenance of marker levels for any of the three mineral markers assessed. Regarding treatment regimen, relatively frequent measurement of serum calcium and phosphorus was positively associated with cinacalcet initiation and relatively frequent measurement of serum PTH with cinacalcet initiation and intravenous VDRA use.
  
  
  
  Our results suggest that increasing frequency of measurements is helpful when serum marker levels exceed the target range, partially via adjustment in the therapeutic regimen. We found no evidence that frequent measurements are helpful when mineral levels are already within target ranges.
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Yokoyama
authors.affiliation: Department of Innovative Research and Education for Clinicians and Trainees (DiRECT), Fukushima Medical University Hospital, Fukushima, Japan.|Institute for Health Outcomes and Process Evaluation Research (iHope International), Kyoto, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kurita
authors.affiliation: Institute for Health Outcomes and Process Evaluation Research (iHope International), Kyoto, Japan.|Institute for Advancement of Clinical and Translational Science (iACT), Kyoto University Hospital, Kyoto, Japan.|Center for Innovative Research for Communities and Clinical Excellence (CIRC2LE), Fukushima Medical University, Fukushima, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Fukuma
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Akizawa
authors.affiliation: Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Isehara, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukagawa
authors.affiliation: Institute for Health Outcomes and Process Evaluation Research (iHope International), Kyoto, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Onishi
authors.affiliation: National Graduate Institute for Policy Studies, Tokyo, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kurokawa
authors.affiliation: Center for Innovative Research for Communities and Clinical Excellence (CIRC2LE), Fukushima Medical University, Fukushima, Japan.|Department of Healthcare Epidemiology, School of Public Health in the Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuhara
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D057966:Calcimimetic Agents / Q000627:therapeutic use*; D002117:Calcitriol / Q000031:analogs & derivatives / Q000627:therapeutic use; D002118:Calcium / Q000097:blood; D000069449:Cinacalcet / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D007564:Japan; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D008903:Minerals; D010281:Parathyroid Hormone / Q000097:blood; D010347:Patient Care Planning; D010758:Phosphorus / Q000097:blood; D006435:Renal Dialysis; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D015415:Biomarkers; D057966:Calcimimetic Agents; D008903:Minerals; D010281:Parathyroid Hormone; D014815:Vitamins; D010758:Phosphorus; D002117:Calcitriol; C051883:maxacalcitol; D002118:Calcium; D000069449:Cinacalcet
keywords: cohort study; mineral metabolism markers; monitoring frequency