At the University of Colorado Department of Medicine’s annual Research Day on April 23, experts stated that individuals typically reach peak bone mineral density in their early to mid-20s, with men having higher density than women. This peak greatly influences the risk of fractures later in life. After reaching this peak, bone density tends to remain stable for a few decades. However, women experience accelerated bone loss during the menopausal transition, while men also experience a decline in bone density with age. Additionally, sleep patterns tend to change over time. Faculty member Christine Swanson, MD, MCR, discussed her clinical research funded by the National Institutes of Health, which explores whether getting enough sleep can help prevent osteoporosis.
“Osteoporosis can develop due to various reasons, including hormonal changes, aging, and lifestyle factors,” stated Swanson, who is an associate professor in the Division of Endocrinology, Metabolism, and Diabetes. “However, some of my patients have no clear explanation for their osteoporosis.
“This is why it’s crucial to search for new risk factors and consider other changes that occur throughout a person’s life, such as bone health – and sleep is one of those factors,” she added.
rnrnHow bone density and sleep change over time
In their early to mid-20s, people reach peak bone mineral density, which is higher in men than in women, according to Swanson. This peak is a major factor in determining the risk of fractures later in life.
After reaching this peak, a person’s bone density remains relatively stable for a couple of decades. However, when women enter the menopausal transition, they experience accelerated bone loss. Men also experience a decline in bone density as they age.
Sleep patterns also change over time. As people age, their total sleep time decreases, and the composition of their sleep also changes.
As we get older, our sleep patterns change. For example, it takes longer to fall asleep as we age, while the deep restorative sleep, known as slow wave sleep, decreases.
According to Swanson, the preference for when to go to sleep and wake up varies across different age groups for both men and women.
What is the connection between sleep and bone health?
Swanson explained that the genes controlling our internal clock are present in all our bone cells.
“When the cells resorb and create bone, they release specific substances into the bloodstream that help us gauge the amount of bone turnover occurring at any given time,” she explained.
These indicators of bone resorption and formation adhere to a daily cycle. The magnitude of this cycle is greater for indicators of bone resorption – the process of breaking down bones – than it is for indicators of bone formation, she noted.
“This rhythmicity is likely crucial for normal bone metabolism and suggests that sleep and circadian disruption could directly impact bone health,” she stated.
ResearcherUnderstanding the Link Between Sleep and Bone Health
To gain more insight into this connection, Swanson and her team conducted a study on how indicators of bone turnover reacted to continuous sleep deprivation and disruption of the body’s natural rhythm.
During the research, the participants resided in a tightly regulated inpatient environment where they were unaware of the time and followed a 28-hour schedule instead of the traditional 24-hour day.
“The purpose of this disruption in circadian rhythm is to replicate the challenges faced during shift work that involves rotating night shifts, and is approximately equivalent to traveling four time zones to the west every day for three weeks,” she explained.The protocol resulted in participants getting less sleep. The research team observed significant negative effects on bone turnover in both men and women due to the sleep and circadian disruption. These effects included decreased markers of bone formation, which were more pronounced in younger individuals of both sexes compared to older individuals. Young women also showed significant increases in a bone resorption marker. This means that the body is forming less bone while still breaking down the same amount.
According to Swanson, insufficient sleep could potentially lead to bone loss, osteoporosis, and an increased risk of fractures over time.
She also mentioned that sex and age could be significant factors, with younger women possibly being the most vulnerable to the negative effects of poor sleep on bone health.
Research in this field is still ongoing, she added.
