Sleep apnea found to affect women's brains more than men's
Sleep apnea affects women and men differently because of sex-specific changes in the brain. This is the finding of researchers at the University of California at Los Angeles (UCLA)’s School of Nursing, School of Medicine, and Brain Research Institute.
The 80 subjects in the study included men and women with newly diagnosed, untreated obstructive sleep apnea (OSA) and healthy controls. Of the participants, 10 female (age mean ± SE: 52.6 ± 2.4 years, apnea-hypopnea index [AHI] 22.5 ± 4.1 events/h) and 20 male (age 48.9 ± 1.7, AHI 25.5 ± 2.9) patients had OSA, and 20 women (age 50.3 ± 1.7) and 30 men (age 49.2 ± 1.4) were controls.
In all the groups, brain fiber integrity was assessed with fractional anisotropy (FA), a diffusion tensor imaging-derived measure. Sleep quality, daytime sleepiness, depression, and anxiety were assessed with questionnaires. The researchers identified regions of differing injury in male vs female OSA patients by assessing brain regions with significant interaction effects of OSA and sex on FA.
The data showed areas of sex-specific, OSA-related FA reductions in women relative to men, including in the bilateral cingulum bundle adjacent to the mid hippocampus, right stria terminalis near the amygdala, prefrontal and posterior-parietal white matter, corpus callosum, and left superior cerebellar peduncle.
Women with OSA reported higher levels of daytime sleepiness, anxiety, and depression as well as reduced sleep quality.
The researchers do not know if the OSA caused the women’s brain damage, if the brain damage led to OSA, or if common comorbidities caused brain damage that led to the OSA. Left untreated, sleep apnea can result in high blood pressure, stroke, heart failure, diabetes, depression, and other serious health problems. The message of this study, the authors said, was that “doctors should consider that the sleep disorder may be more problematic and therefore need earlier treatment in women than in men.”
The study appears in the December 2012 issue of the journal Sleep.
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