Posture, Age, Menopause, and Osteopenia Do Not Influence the Circadian Variation in the Urinary Excretion of Pyridinium Crosslinks

Annette Schlemmer, Christian Hassager, Brian Juel Pedersen, Claus Christiansen

Research output: Contribution to journalJournal articleResearchpeer-review


This study was performed to investigate whether the circadian variation in urinary pyridinium crosslinks is related to physical activity, age, the menopause, and asymptomatic osteopenia. We measured urinary pyridinoline/creatinine (Pyr/Cr) and deoxypyridinoline/creatinine (D-Pyr/Cr) in 9 healthy premenopausal women in two 27 h studies, before and at the end of 5 days of total bed rest. Both Pyr/Cr and D-Pyr/Cr showed highly significant circadian variations, with the peak at night and the nadir during the day (p lt 0.001). The 5 days of complete bed rest produced no changes in the circadian pattern, but a general increase of 28% was observed in pyridinium crosslinks. A group of 12 healthy, early postmenopausal women (aged 55 +- 2 years), 12 healthy, elderly postmenopausal women (aged 73 +- 1 years), and 12 elderly osteopenic but otherwise healthy women (aged 73 +- 1 years) were also studied for 27 h. All three groups showed highly significant (p ltoreq 0.001) circadian variations in the urinary excretion of pyridinium crosslinks. As expected, both Pyr/Cr (p lt 0.05) and D-Pyr/Cr (p lt 0.001) increased at the time of menopause, but the circadian variations in Pyr/Cr and D-Pyr/Cr were similar in all groups studied. We conclude that the circadian variation in the urinary excretion of pyridinium crosslinks is independent of physical factors. Furthermore, the circadian variation in pyridinium crosslinks was not related to age, menopausal status, or asymptomatic osteopenia.
Original languageEnglish
JournalJournal of Bone and Mineral Research
Issue number12
Pages (from-to)1883-1888
Number of pages6
Publication statusPublished - 1994
Externally publishedYes


  • Adult
  • Age Factors
  • Aged
  • Amino Acids
  • Bone Diseases, Metabolic
  • Circadian Rhythm
  • Creatinine
  • Female
  • Humans
  • Middle Aged
  • Postmenopause
  • Posture
  • Premenopause
  • 63800-01-1 pyridinoline
  • 90032-33-0 deoxypyridinoline
  • AYI8EX34EU Creatinine
  • Primates Mammalia Vertebrata Chordata Animalia (Animals, Chordates, Humans, Mammals, Primates, Vertebrates) - Hominidae [86215] human
  • CREATININE 60-27-5
  • PYRIDINIUM 16969-45-2
  • PYRIDINOLINE 63800-01-1
  • 07200, Circadian rhythms and other periodic cycles
  • 10064, Biochemistry studies - Proteins, peptides and amino acids
  • 10069, Biochemistry studies - Minerals
  • 12010, Physiology - Exercise and physical therapy
  • 15504, Urinary system - Physiology and biochemistry
  • 16504, Reproductive system - Physiology and biochemistry
  • 18004, Bones, joints, fasciae, connective and adipose tissue - Physiology and biochemistry
  • 18006, Bones, joints, fasciae, connective and adipose tissue - Pathology
  • 24500, Gerontology -
  • Chemical Coordination and Homeostasis
  • Human Medicine, Medical Sciences
  • Movement and Support
  • Reproduction
  • Biosynchronization
  • Geriatrics
  • Reproductive System
  • Skeletal System
  • Urinary System

Cite this