Study finds link between circadian rhythms and bone resorption

How our bodies break down and remove old and damaged bone tissue is linked to our inner circadian clock, according to a new study from the University of Surrey and the University of Sheffield.

Published in Scientific Reports, researchers focused on the processes involved in bone renewal: bone resorption (which allows the body to breakdown and remove old or damaged bone) and bone formation (which builds new bone).

The research team examined blood samples from 22 young adults, collected every two hours for the span of 26 hours, and measured the presence of two markers: serum procollagen type I N-terminal propeptide (sPINP), linked to bone formation and C-terminal telopeptide of type 1 collagen (sCTX), linked to bone resorption.

Samples were collected under carefully controlled laboratory conditions that allowed robust assessment of circadian rhythmicity in bone turnover markers. The findings show that while bone formation is not tied to our body’s cycle, bone resorption is closely linked to our internal circadian clock. These novel findings provide important insights into the temporal regulation of bone metabolism.

Dr Andrea Darling, Nutritional Sciences Postdoctoral Researcher at the University of Surrey and lead author of the study, said:

“This study has established a clear link between circadian rhythms and bone resorption (breakdown), which is a key process in maintaining bone integrity. As our study focused on healthy younger people it will be interesting to find out, through future research, whether older individuals, and more specifically, those with osteoporosis, present disrupted circadian rhythms.”

Professor Debra Skene, FMedSci, Section of Chronobiology at the University of Surrey and senior author of the study said:

“Successful collaboration between chronobiology, nutritional sciences and bone metabolism researchers has led to these exciting new findings. More research into how misalignment of circadian rhythms, often seen in shift workers, might affect bone density and conditions like osteoporosis, is needed.”

Professor Richard Eastell, Professor of Bone Metabolism at the University of Sheffield and one of the authors of the study, commented:

“We knew that there was a diurnal rhythm of bone resorption markers already, but what this study has added is the constant routine protocol which allows us to conclude that the rhythm is a circadian one.”

Craig Jones, Chief Executive of the Royal Osteoporosis Society, said:

“This fascinating study sheds new light on the fundamental biology of how our bones are renewed. By showing that bone breakdown is tied to the body’s circadian rhythms, it opens up important new questions about whether disrupted sleep and shift work could increase people’s risk of osteoporosis. As the UK’s leading osteoporosis charity, we’re proud to have funded this work, and we look forward to seeing how it could help improve prevention and treatment in the future.”