April 21, 2022
Lower-than-normal levels of sex hormones can increase the risk of shoulder injuries in men and women, according to a new study.
The research conducted at the University of Utah, specifically examined the likeliness of tears to the rotator cuff, the group of muscles and tendons that surround the shoulder joint and hold the head of a person's upper arm bone into the shoulder socket.
The study looked at the hormone levels of people younger than 65, who had rotator cuff surgeries, and researchers found that women with low levels of estrogen had a 48% greater chance of rotator cuff injuries compared to women with normal estrogen levels. Men with low levels of testosterone had a 89% greater likelihood.
When a tear to the rotator cuff occurs, the tendons can become partially, or fully, detached from head of the upper arm bone, called the humerus. Symptoms of a rotator cuff tear include shoulder pain, limited arm mobility, muscle weakness and cracking sounds when moving arm.
Almost 2 million Americans visit doctors each year because of rotator cuff pain. While the majority of rotator cuff tears can be treated nonsurgically with medications and therapy, more severe cases can require surgical repair.
The researchers say it is possible that the low levels of estrogen and testosterone could contribute to the weakening of the muscles and tendons in the rotator cuff, increasing the chances of a tear occurring.
"It's been known for a long time that when you have low estrogen and testosterone levels, that leads to osteoporosis or weak bones. And as the bones get weaker, it compromises tendon-bone attachments, and that's basically what rotator cuff tears are," Dr. Peter Chalmers, the study's co-author and an orthopedic surgeon at the University of Utah in Salt Lake City, told U.S News & World Report.
He explained, "Testosterone is an anabolic steroid, which means it builds muscle. It's well accepted that when a muscle builds, the tendon has to build to compensate for the increased force by the muscle. So it may be that when testosterone levels are low, the tendons no longer receive that signal, and then the attachment can weaken."
Chalmers and his team say that the sex hormone deficiencies may also slow down the healing process. More research is needed to determine if treating these deficiencies should be recommended to modify the risk of rotator cuff tear.
The findings are based on health insurance data of almost 230,000 men and women who underwent rotator cuff repair between 2008 and 2017. The patients' average age was 54. They were compared to other participants who didn't have surgeries.
Twenty-seven percent of the women who had surgery had low levels of estrogen while 7% of men who underwent repair of their rotator cuff were deficient in testosterone.
When the researchers analyzed the Veterans Administration Genealogy database, they found that women with sex hormone deficiencies had 2.5 times the risk for rotator cuff repair. Men with testosterone deficiency were three times more likely to undergo the surgery.
Beyond should problems, researchers say the results show how sex hormone deficiencies can impact many aspects of a person's health. The study is published in the Journal of Bone and Joint Surgery.