(Reuters Health) - Former professional U.S. football players with a history of concussions may be more likely to experience low testosterone and erectile dysfunction later in life, a recent study suggests.
Researchers examined survey data collected from 3,409 mostly middle-aged former National Football League (NFL) players from 2015 to 2017. Overall, 18.3% of them had low testosterone and 22.7% had erectile dysfunction.
Men who reported the most concussion symptoms at the time of any football-related head injuries were more than twice as likely to experience low testosterone and 72% more likely to have erectile dysfunction than their counterparts who reported few, if any, concussion symptoms when they got hurt playing the game.
“Even if we account for older age, diabetes, use of prescription pain medication, obesity, heart disease, previous use of performance enhancing drugs, sleep apnea, hypertension and alcohol use, we still saw a very strong signal between concussion symptoms and risk of erectile dysfunction or low testosterone,” said Rachel Grashow, lead author of the study and a researcher at the Harvard T.H. Chan School of Public Health in Boston.
“Unfortunately, this study does not shed any light on whether there are actions that can be taken after a head injury to minimize risk of sexual health issues,” Grashow said by email. “However, erectile dysfunction and low testosterone are conditions that can be very responsive to interventions like medications, as well as other positive health activities like exercise, maintaining a healthy diet and treating sleep conditions.
To assess the severity of concussion symptoms after any head injuries, researchers asked players if they experienced a blow to the head, neck or upper body followed by symptoms like headaches, nausea, dizziness, loss of consciousness, memory problems, disorientation, confusion, seizures, visual problems, or feeling unsteady on their feet.
Researchers also asked participants if a healthcare provider had ever recommended that they take prescription medicine for low testosterone or erectile dysfunction.
Former players in the study were 53 years old, on average, and had played in the NFL for an average of 6.8 seasons.
The link between concussion symptoms and low testosterone and erectile dysfunction was strongest for men who currently used prescription painkillers or suffered sleep apnea, a nighttime breathing disorder, researchers report in JAMA Neurology.
The link was also stronger for men who reported both low testosterone and erectile dysfunction than for men who only had one of these issues.
The study wasn’t designed to prove whether or how concussion symptoms might directly cause low testosterone or erectile dysfunction.
It’s possible that multiple hits to the head or a single severe brain injury could damage the thin tissue connecting the brain to the pituitary gland, which regulates testosterone and other hormones, Grashow said.
“When the brain receives multiple hits or one severe impact, the neuronal connections to other parts of the brain are sheared which reduces its ability to communicate with the rest of the body,” Grashow said. “Damage to blood vessels can limit circulation to the pituitary, further impairing its ability to function properly.”
However, concussions won’t immediately produce low testosterone or erectile dysfunction, and these conditions can have many other causes, said Dr. Jack Tsao, a neurology professor at the University of Tennessee Health Science Center in Memphis.
“The direct link to concussion has not yet been proven,” Tsao, who wasn’t involved in the study, said by email.
“If a man has erectile dysfunction, he should seek medical attention where blood tests can be ordered to determine if there is low testosterone or another cause,” Tsao advised. “If erectile dysfunction or low testosterone is present then a decision should be made by the man in conjunction with the healthcare provider to decide if testosterone replacement therapy or medications for erectile dysfunction should be prescribed.”
SOURCE: bit.ly/32enPZB JAMA Neurology, online August 26, 2019.