Taking Testosterone? Watch for Polycythemia and Sleep Apnea, Experts Warn

Taking Testosterone? Watch for Polycythemia and Sleep Apnea, Experts Warn

Men undergoing testosterone replacement therapy (TRT) should be aware of links between obstructive sleep apnea (OSA) and polycythemia, an abnormal amount of circulating red blood cells in the bloodstream, suggests a recent Journal of Sexual Medicine study.

TRT has grown in popularity over the years. It is generally approved for men whose bodies don’t produce enough testosterone on their own due to problems in the testes (the glands that make the hormone) or areas of the brain that trigger testosterone production.

However, men’s testosterone levels gradually decline as they get older, too. Some take testosterone to manage symptoms like low libido, moodiness, and fatigue.

TRT does have side effects. One is polycythemia (also called erythrocytosis). As the number of red blood cells grows, the blood can thicken, increasing the risk for stroke. Usually, men who develop polycythemia can lower their testosterone dose or switch to a different formulation.

Polycythemia is also associated with obstructive sleep apnea, a disorder that causes a person to stop breathing for short intervals while asleep. Studies have found that men with low testosterone, and those on TRT, might be more likely to have OSA.

The authors of the current study wanted to learn more about the relationship among TRT, polycythemia, and OSA.  

They analyzed the medical charts of 474 men in their clinic who were on TRT. About 13% of the men were diagnosed with polycythemia. Of this group, 52% were also diagnosed with OSA.

There was a “strong positive association” between polycythemia and an OSA diagnosis in these men, the researchers said.

They further studied the subgroup of men with both polycythemia and OSA. All of the men were prescribed CPAP (continuous positive airway pressure) for their sleep apnea, although about half did not comply with their instructions. As for polycythemia, some of the men were treated with phlebotomy (blood draws to reduce blood volume) and some had their TRT dose lowered.

The researchers found that in this subgroup, body mass index (BMI) was “the only risk factor strongly associated with OSA.”

Men on TRT, especially those with a higher BMI, should be screened for OSA if they develop polycythemia, the authors concluded.

Men whose OSA is undiagnosed or poorly treated could be at higher risk for cardiovascular problems later on. But proper OSA treatment could have cardiovascular benefits in these men, they added.



Hecht, Marjorie

“Secondary Polycythemia (Secondary Erythrocytosis)”

(February 8, 2019)


Lights, Verneda

“Obstructive Sleep Apnea”

(Updated: March 31, 2017)


The Journal of Sexual Medicine

Lundy, Scott D., MD, PhD, et al.

“Obstructive Sleep Apnea Is Associated With Polycythemia in Hypogonadal Men on Testosterone Replacement Therapy”

(Full-text. Published: April 16, 2020)