medwireNews: Women, particularly those with hypertension or obesity, have high rates of sleep apnea, study findings show.
As many as 50% of women in the general population fulfilled the criteria for sleep apnea, and it was present in 80% of women with hypertension and 84% of obese women.
"We were very surprised to find such a high occurrence of sleep apnea in women, as it is traditionally thought of as a male disorder," lead author Karl Franklin (Umeå University Hospital, Sweden) said in a press statement.
The researchers also note that, unlike men, women with sleep apnea often did not experience daytime sleepiness and habitual snoring was uncommon. These are the main reasons for seeking medical help, so this finding may explain why "sleep apnea has not been observed as a public health problem in women," say the researchers.
By contrast, sleep apnea in women was associated with increasing age, hypertension, and obesity (body mass index >30 kg/m2).
"These findings suggest that clinicians should be particularly aware of the association between sleep apnea and obesity and hypertension, in order to identify patients who could also be suffering from the sleep disorder," said Franklin.
The researchers obtained full-night polysomnographic recordings for 400 women from a random sample of 10,000 women, aged 20-70 years, who responded to a postal survey conducted as part of a study entitled "Sleep and Health in Women."
Obstructive sleep apnea, defined as at least five apnea or hypopnea events per hour of sleep, was diagnosed in 50% of women, and affected as many as 75% of women aged 55-70 years.
Meanwhile, severe sleep apnea (apnea-hypopnea index =30) occurred in 14% of women aged 55-70 years and in 31% of obese women aged 55-70 years.
"It is necessary to identify these women with unrecognized severe sleep apnoea as they probably run an increased risk of early death, without adequate treatment for obstructive sleep apnoea," the researchers stress.
They also note in the European Respiratory Journal that daytime sleepiness and hypertension were observed as two phenotypes of sleep apnea. In all, 34% of women with sleep apnea were sleepy during the day, while 25% had hypertension. Only 3.6% suffered from both sleepiness and hypertension.
Franklin told medwireNews: "More women should be investigated for suspicion of sleep apnea. I also think that more women who are suspicious of having sleep apnea or are overweight or suffer from hypertension should seek sleep apnea investigation."
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