Effect of ovariectomy on inflammation induced by intermittent hypoxia in a mouse model of sleep apnea

• Obstructive sleep apnea (OSA) presents gender and pre-vs-postmenopausal differences.
• No experimental data are available on how sexual hormones modulate OSA consequences.
• Ovariectomy reduced the inflammation induced by intermittent hypoxia modeling OSA.
• This study highlights the role of sexual hormones in modulating the consequences of OSA.

Patient data report marked gender and pre-vs-postmenopausal differences in obstructive sleep apnea (OSA). However, no experimental data are available on how sexual hormones modulate OSA consequences. Here we report novel results on estrogen-modulated heart and brain inflammation in female mice subjected to intermittent hypoxia, a major injurious challenge in OSA. C57BL/6J (14-week old) intact and ovariectomized mice (n = 6 each) were subjected to intermittent hypoxia (20 s at 5% and 40 s at 21%, 60 cycles/h; 6 h/day). Identical intact and ovariectomized groups breathing room air were controls. After 30 days, the gene expressions of interleukins 6 and 8 (IL-6, IL-8) in the brain and heart tissues were measured. Whereas, compared with normoxia, intermittent hypoxia considerably increased IL-6 and IL-8 gene expressions in intact females, no change was found in ovariectomized mice when comparing normoxia and intermittent hypoxia. These data suggest that estrogens modulate the inflammatory effects of intermittent hypoxia and point to further studies on the role played by sex hormones in OSA.