Lower levels of sex hormones might be tied to tears of the shoulder's rotator cuff in men and women, a new study suggests.
Among women with low levels of estrogen, researchers found the odds of a rotator cuff tear were 48% higher, compared with women with normal estrogen levels. Among men, the odds of a rotator cuff tear were 89% higher among those with low levels of testosterone.
"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," said study co-author Dr. Peter Chalmers. He is an orthopedic surgeon and clinical instructor at the University of Utah in Salt Lake City.
Chalmers noted that because this is an observational study, it can't prove that low levels of testosterone and estrogen cause rotator cuff tears, only that the two are associated.
He added, however, that biological explanations may exist.
For example, Chalmers said, "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."
Not only can sex hormone deficiencies lead to rotator cuff tears, they may also hinder healing, the study authors suggested.
Because both deficient testosterone and estrogen levels can be treated, this risk might be modifiable. "But we don't have enough evidence to recommend that yet," Chalmers said.
"We're going to do more studies to try to determine if that would be appropriate. But certainly, this study suggests that this may be a pathway going forward," he said.
The rotator cuff has tendons that attach the upper arm bone (humerus) to the shoulder blade. When one or more of these tendons is torn, the tendon no longer fully attaches to the head of the humerus, resulting in pain.
Rotator cuff tears are common. Each year, almost 2 million Americans see doctors because of a rotator cuff problem, according to the American Academy of Orthopaedic Surgeons. For the most severe cases, surgical repair is needed.
For the study, Chalmers and his colleagues used a health insurance database to collect data on nearly 230,000 men and women, average age 54, who had surgery to repair a torn rotator cuff from 2008 through 2017. They matched these patients with similar people who didn't have the surgery.
Among those who had surgery, 27% of women were deficient in estrogen and 7% of men were deficient in testosterone, compared with 20% of the women and 4% of the men who didn't have surgery, the investigators found.
To confirm their findings, the researchers analyzed the Veterans Administration Genealogy database. They found that rotator cuff repair was about three times more likely for women with estrogen deficiency and for men with testosterone deficiency.
"This paper provides additional evidence that these tendon tears are metabolic in origin," Chalmers said. "So I think for people who have other underlying metabolic abnormalities, they need to understand that these deficiencies are bad for your overall health and have a ripple effect all over the body, even into the shoulder."
Dr. Randy Cohn, chief of the division of orthopedic surgery at Huntington Hospital in Huntington, N.Y., said it's not surprising that these hormones might play a part in rotator cuff tears.
"We know that systemic factors affect musculoskeletal pathophysiology. We know this in the setting of osteoporosis hip fractures, where estrogen deficiency has been shown to cause demineralization of bone and increases risk for subsequent fracture. We know that systemic factors play a role in tendon muscle healing," Cohn said.
"It's not surprising that testosterone and estrogen help grow muscle and help with healing. It's not a big leap of faith to think that sex hormone deficiency can be associated with poor healing," Cohn added.
He and Chalmers said that taking testosterone and estrogen supplements to prevent rotator cuff tears is warranted by the findings of this study.
To prevent rotator cuff tears, Cohn advises living a healthy lifestyle. If tears occur, he believes that physical therapy and over-the-counter painkillers are the best treatment.
"Rotator cuff surgery is really only indicated with a failure of extensive nonoperative and conservative care," he advised.
The report was published April 12 in the Journal of Bone and Joint Surgery.
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SOURCES: Peter Chalmers, MD, orthopedic surgeon, clinical instructor, University of Utah, Salt Lake City; Randy Cohn, MD, chief, division of orthopedic surgery, Huntington Hospital, Huntington, N.Y.; Journal of Bone and Joint Surgery, April 13, 2022