Scientists at the Medical College of Wisconsin, in a team led by Carol Everson, Ph.D., professor of neurology, cell biology, neurobiology and anatomy, have discovered abnormalities in bone and bone marrow in rats undergoing chronic lack of sleep…
Sleep is paramount for the health of all human organs including our skeletal system.
In this study the doctor’s involved tested rats who were sleep deprived and found that bone marrow and growth factors were greatly hindered from insomnia causing a loss in bone mineral density.
Two groups of test subjects were exposed to constant ambient light and forced ambulation. To follow the impact of sleep-restriction on these two groups, electrodes were implanted to measure wakefulness and sleep stages. The rats were followed over 72 days of restricted sleep to determine the impact on their bones.
The sleep deprived rats had a decrease in bone formation, undiminished resorption and decreased bone marrow fat. These findings were ascertained through blood testing of osteocalcin, insulin-like growth factor 1 (IGF-1) and plasma marker levels. Decreases seen in bone mineral densities were obtained through the use of a DXA scan and bone measurements, in the tibia and femurs. Due to the imbalance between formation and resorption, these rats developed osteopenia as a result of the sleep deprivation.
We’ll have to wait and see if these findings can be attributed to humans, but it seems likely according to Dr. Everson. The laboratory rat is the most common model for evaluation of developmental and osteoporotic processes in humans because of comparable histomorphometric changes, biochemical markers and methodology for bone densitometry. Implications of sleep loss on bone turnover and marrow hematopoiesis are potentially far-reaching. If the same phenomenon occurs in humans, chronic sleep restriction could cause osteopenic bone leading to increased fracture risk, decreased bone healing after surgery and decreased bone development.
Many of us face bone loss as we age and this may be one clue that explains why we lose bone mass during aging with its accompanying insomnia.
Everson, Folley and Toth (2012, September) Chronically inadequate sleep results in abnormal bone formation and abnormal bone marrow in rats. Retrieved from http://ebm.sagepub.com/content/237/9/1101.full