Osteocalcin in human serum: A circadian rhythm

Caren M. Gundberg, Morri E. Markowitz, Mark Mizruchi, John F. Rosen

Research output: Contribution to journalArticlepeer-review

200 Scopus citations

Abstract

Osteocalcin, the vitamin K-dependent protein synthesized in bone, is found in blood. The level of circulating osteocalcin has recently been used as an indicator of the rate of bone turnover. We measured serum osteocalcin during 24-h periods in 6 normal 20- to 30-yr-old men and 4 women. Blood was sampled via an indwelling venous catheter every 30 or 60 min for 24 h. Circadian rhythmicity in circulating osteocalcin was found in 9 of the 10 individuals studied. Osteocalcin levels fell during the morning, rose in the afternoon and early evening, and reached a peak nocturnally. There were no consistent correlations between osteocalcin concentrations and circulating levels of ionized calcium, total calcium, or inorganic phosphate in the subjects tested. This study illustrates the importance of regulating the time of blood sampling for osteocalcin determinations in clinical investigations of metabolic bone disease.

Original languageEnglish (US)
Pages (from-to)736-739
Number of pages4
JournalJournal of Clinical Endocrinology and Metabolism
Volume60
Issue number4
DOIs
StatePublished - Apr 1985

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical

Fingerprint Dive into the research topics of 'Osteocalcin in human serum: A circadian rhythm'. Together they form a unique fingerprint.

Cite this