The data came from two randomised trials run between 2014 and 2017. 70 adults with sleep apnea: 58 men and 12 women, 11 of them past menopause. All had used CPAP for at least a year, on more than 80% of days. Breathing events averaged about 51 per hour when they were first tested. 37 people kept their usual CPAP. 33 were switched for two weeks to CPAP set too low to work. Blood was taken at the start and after the two weeks.

Two weeks is short, and the effects were small. 58 of the 70 were men, so the results say little about women. Estradiol was not measured. Free testosterone, FSH and LH came from one trial only, so those results are exploratory. The DHEA-S result was an extra analysis added afterwards. The trials were designed to study brain blood vessels and exhaled breath, not hormones. The paper reports hormone levels only, and the authors call for studies that measure sexual function itself.

CPAP Break and Sex Hormones: A 2026 Study

Two randomised trials took 33 regular CPAP users off effective CPAP for two weeks. Testosterone and most other sex hormones showed no significant change. Only DHEA rose, by a small amount.

PulseOxTracker Team9 October 2026

Infographic summarising a 2026 study. Two weeks off CPAP: most sex hormones did not move. What changed off CPAP, against staying on it: DHEA, the one hormone that changed, rose by 0.86 ng/ml, and breathing events came back, up 31.8 per hour. Who was studied: 70 adults with sleep apnea, 58 men and 12 women. All had used CPAP regularly for at least a year. 33 got a CPAP set too low to work for 2 weeks, 37 kept theirs. Two randomised trials in Zurich, 2014 to 2017. What the morning blood tests showed. Testosterone: no significant change. Androstenedione, progesterone, FSH, LH: no significant change. DHEA: up 0.86 ng/ml, 95% CI 0.17 to 1.56, p = 0.016. DHEA-S: rose a little more off CPAP, not significant, p = 0.089. Daytime sleepiness: up 3.29 points on a questionnaire in one of the two trials. What it cannot show: short, mostly men, and hormone levels only. Two weeks only. No sexual function results. Estradiol was not measured. Free testosterone, FSH and LH came from one trial only (exploratory). The DHEA rise was small and its meaning is not known. Source: Grewe et al. 2026, Sleep Medicine: X. — A summary of the 2026 study: who took part, what happened to sex hormone levels after two weeks off CPAP, and what the study cannot show.

Problems with sex drive and sexual function are common in people with sleep apnea. Earlier research found that CPAP helps with them, but doesn't reliably change testosterone or estradiol. A 2026 study from Zurich checked whether other sex hormones respond to CPAP.

Who was studied?

The data came from two randomised trials run between 2014 and 2017.

70 adults with sleep apnea: 58 men and 12 women, 11 of them past menopause.
All had used CPAP for at least a year, on more than 80% of days.
Breathing events averaged about 51 per hour when they were first tested.

37 people kept their usual CPAP. 33 were switched for two weeks to CPAP set too low to work. Blood was taken at the start and after the two weeks.

Did the break bring the apnea back?

Yes. Against the CPAP group:

Breathing events rose by 31.8 per hour.
The oxygen desaturation index, the number of oxygen dips per hour, rose by 31.5.
In one of the two trials, a daytime sleepiness score rose by 3.29 points.

What happened to the hormones?

Mostly nothing. The study found no significant effect on:

Testosterone.
Androstenedione, progesterone and 17-hydroxyprogesterone.
FSH and LH, the pituitary hormones that drive the ovaries and testes.

One hormone moved. DHEA, a weak hormone the body turns into other sex hormones, rose by 0.86 ng/ml (95% CI 0.17 to 1.56, p = 0.016). Starting levels were about 2.1 ng/ml.

The authors expected a fall. Their explanation is that DHEA is also released as part of the body's stress response. They suggest sexual problems in sleep apnea may run through stress pathways, which the study did not test.

DHEA-S, a related hormone, rose a little more off CPAP, but not significantly (p = 0.089). People with higher diastolic blood pressure had higher DHEA.

What are the limits?

Two weeks is short, and the effects were small.
58 of the 70 were men, so the results say little about women.
Estradiol was not measured.
Free testosterone, FSH and LH came from one trial only, so those results are exploratory.
The DHEA-S result was an extra analysis added afterwards.
The trials were designed to study brain blood vessels and exhaled breath, not hormones.
The paper reports hormone levels only, and the authors call for studies that measure sexual function itself.

What can you do with this?

The break was supervised by researchers, and any change to your own therapy is a decision for you and your doctor.

On CPAP already? See tracking your oxygen alongside CPAP.

Not a medical device. Does not diagnose, treat or prevent any condition. Discuss results and changes with a clinician.

References

Grewe FA, Thiel S, Haile SR, Peitzsch M, Schwarz EI, Sievi NA, Beuschlein F, Kohler M, Gaisl T. Effects of CPAP withdrawal on sex hormone levels in patients with obstructive sleep apnoea: data from two randomised, controlled trials. Sleep Medicine: X. 2026;12:100201. doi:10.1016/j.sleepx.2026.100201