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Circadian variation of mineral and bone parameters in end-stage renal disease. J Nephrol 2015 Jun;28(3):351-9 PMID: 25138650 PMCID: PMC4663981

Pubmed ID

25138650

Abstract

BACKGROUND: Mineral and bone parameters are actively managed in end-stage renal disease (ESRD). However, whether these undergo circadian variation is not known. We investigated the circadian variation of mineral and bone parameters in patients on long-term hemodialysis.

METHODS: Seventeen ESRD patients on long-term hemodialysis and eight volunteers without kidney disease were enrolled. Subjects had all medications that affect calcium-phosphate-parathyroid hormone balance (phosphate binders, vitamin D analogues, and calcimimetics) discontinued. Thereafter, for a period of 5 days, subjects consumed a diet controlled in calcium (1,200 mg per day) and phosphorus (1,000 mg per day) content. On the sixth day (a non-dialysis day for the ESRD patients), enrollees underwent twelve 2-h blood draws for phosphate, ionized calcium, parathyroid hormone (PTH), total 25-hydroxy vitamin D (25OHD), and fibroblast growth factor-23 (FGF-23).

RESULTS: In the ESRD patients plasma phosphate demonstrated significant circadian variation (P < 0.00001). The peak occurred around 3:30 am and nadir occurred around 11:00 am. Ionized calcium (P = 0.0036), PTH (P = 0.0004) and 25OHD (P = 0.009) also varied significantly during the circadian period; for ionized calcium peak and nadir occurred around 12:15 pm and 8:00 pm, parathyroid hormone 5:45 pm and 10:15 am, and 25OHD 9:45 am and 4:00 pm respectively. FGF-23 did not show a significant circadian variation. Only phosphate (P < 0.0001) and PTH (P = 0.00008) demonstrated circadian variation in the control group.

CONCLUSIONS: Blood concentrations of phosphate, calcium, PTH and 25-hydroxy vitamin D, exhibit a circadian variation in patients with ESRD. Knowledge of these phenomena is pertinent for the interpretation of clinical testing.

Author List

Trivedi H, Szabo A, Zhao S, Cantor T, Raff H

Authors

Hershel Raff PhD Professor in the Medicine department at Medical College of Wisconsin
Aniko Szabo PhD Associate Professor in the Institute for Health and Equity department at Medical College of Wisconsin




Scopus

2-s2.0-84930197788   10 Citations

MESH terms used to index this publication - Major topics in bold

Adult
Biomarkers
Bone and Bones
Calcium
Case-Control Studies
Circadian Rhythm
Female
Fibroblast Growth Factors
Humans
Kidney Failure, Chronic
Male
Middle Aged
Parathyroid Hormone
Phosphates
Predictive Value of Tests
Renal Dialysis
Reproducibility of Results
Time Factors
Treatment Outcome
Vitamin D
jenkins-FCD Prod-299 9ef562391eceb2b8f95265c767fbba1ce5a52fd6