Studies link sleep apnea to osteoporosis

New research conducted by scientists at Oregon Health and Science University in Portland, Oregon, found a connection between sleep apnea and osteoporosis. The findings were supported by results derived from past studies and were published in the Journal of Bone and Mineral Research.

Sleep apnea may be leading cause of osteoporosis
A significant number of Americans are impacted by sleeping disorders. Sleep apnea in particular is one of the most common disorders, affecting approximately 18 million Americans, according to the Sleep Disorders Guide. Sleep apnea causes short interruptions in breathing during sleep, while the most common form, obstructive sleep apnea, occurs when the air passages are blocked during sleep. Mild cases of the condition are known to cause people to feel exhausted upon waking, while more severe forms can lead to high blood pressure, depression, hypertension and even stroke. Of those impacted by the disorder, there are around 6 million who experience moderate to severe forms. 

Meanwhile, there is a significant amount of Americans who also experience low bone mass, currently including about 54 million over the age of 50. Of this number, around 10 million have been diagnosed with osteoporosis, which involves the breakdown of bones that can eventually lead to limited mobility and fractures.

The authors of the new research believe that sleep apnea may be a leading cause of osteoporosis, interfering with bone remodeling, which is essential for maintaining bone health. The process involves the removal of older bone, which is then replaced by new bone tissue that slowly rebuilds. This occurs both while people are awake and while they are sleeping. 

After examining past research on bone metabolism, the team noticed several indications that during sleep, the disorder halts the remodeling process, preventing the mature bone from being replaced. Without the renewal of bone tissue, people become more at risk of osteoporosis.

"If sleep disorders like obstructive sleep apnea affect bone metabolism, they may have diagnostic and therapeutic implications for many patients, including those affected by sleep apnea in their early, bone modeling years," said lead author Dr. Christine Swanson.

Potential for osteoporosis prevention
Past studies have also shown that ongoing sleep disruptions may ultimately impact the entire skeletal system, one of which was performed in April 2014 by the Endocrine Society. The team used records from the National Health Insurance program to track 1,377 patients who were diagnosed with obstructive sleep apnea at some point from 2002 to 2008. The researchers looked for osteoporosis diagnoses in the group of patients and then compared this number to another group of 20,655 people within the same age range with the sleep disorder. 

They found that the number of patients diagnosed with both sleep apnea and osteoporosis was 2.7 times greater than the other patients, even after accounting for all factors, such as various medical problems, age, gender, monthly income and geographic location.

"Ongoing sleep disruptions caused by obstructive sleep apnea can harm many of the body's systems, including the skeletal system," said one of the study's authors, Kai-Jen Tien, M.D. "When sleep apnea periodically deprives the body of oxygen, it can weaken bones and raise the risk of osteoporosis. The progressive condition can lead to bone fractures, increased medical costs, reduced quality of life and even death."

Both studies emphasize the importance of grasping a clearer understanding of the direct impact sleep apnea has on the skeletal system because a growing number of people are diagnosed with obstructive sleep apnea every day. Patients and their doctors should be fully aware that they are at a greater risk of developing other serious conditions, like osteoporosis. The new knowledge may also help develop preventative measures for osteoporosis.