Doc Talk

Obstructive sleep apnoea in women can be overlooked

ST ILLUSTRATION: ADAM LEE

Severe OSA, if left untreated, has been shown to be linked to cardiovascular death in women

For a long time, Madam S. could not understand why she felt so drained in the morning despite clocking seven to eight hours of sleep every night. She dragged herself to work, had difficulty focusing and would sometimes doze off during meetings.

Taking three to four cups of coffee to keep going was of no help to her at all. In fact, she had to switch to a less stressful job.

She noticed that the situation worsened over the past year - after she hit menopause.

Her personal and social life was affected too, as she would feel too tired to spend time with her family or friends. She was easily irritable and would snap at her husband and two children at the slightest provocation. On a few occasions, she woke up in the middle of the night gasping for air.

Worried, she went to the emergency department at least five or six times over the past year.

Women tend to be underdiagnosed for obstructive sleep apnoea. A reason for this is that people, including doctors, have preconceived ideas of a "typical" sufferer. They think that such people tend to be overweight, middle-aged men.

From heart to lung specialists, all gave her a clean bill of health.

It was not until she went on a tour with her friends that she suspected what could be the cause of her misery. Her friends complained about her loud snoring. In fact, they noticed that she was struggling to breathe and was gasping during her sleep.

She sought help at the Singapore General Hospital's (SGH) sleep disorders unit, where she underwent a sleep test.

She had to sleep overnight at the hospital while the technician monitored her brain waves, breathing patterns, blood oxygen level and snoring intensity.

Her mysterious health problems were solved when she was diagnosed with obstructive sleep apnoea (OSA).

WOMEN SUFFERERS TEND TO GO UNDETECTED

An estimated 15 to 20 per cent of adults in Singapore suffer from this sleep disorder.

At SGH, where over 1,000 sleep tests are performed every year to identify OSA, about 200 of these are done on women patients.

Women tend to be underdiagnosed for OSA. A reason for this is that people, including doctors, have preconceived ideas of a "typical" OSA sufferer. They think that such people tend to be overweight, middle-aged men.

These male patients tend to snore very loudly, have choking and gasping episodes, unrefreshing sleep and daytime sleepiness.

Women, on the other hand, may experience unspecific symptoms like fatigue, insomnia, morning headaches, a lack of energy, mood disturbances and depression.

They may also suffer from "cold" hands and feet, aches and pains, and low blood pressure.

Physicians, however, often overlook the common diagnosis of OSA because women do not snore loudly, and complain more of fatigue rather than sleepiness during the day.

The incidence of OSA tends to be low in women aged 25 to 50. But this figure increases to match that of male sufferers at 50 to 55, when women undergo menopause.

This is due to a drop in female hormones that stabilise breathing and make the upper airway less prone to collapse - which was what happened in Madam S.'s case.

Severe OSA that is left untreated has been shown to be linked to cardiovascular death in women.

Compared to men, women with OSA are more prone to mood disturbances like anxiety and depression, hypothyroidism, joint diseases, cognitive impairment and dementia.

These additional diseases can explain the elevated risk of dying in women, compared with men.

Women with OSA often report worse health statuses than men, and rack up 1.3 times higher healthcare costs. They may also be treated for anxiety and depression.

Recent research has also shown that OSA tends to get worse during pregnancy, which can potentially harm the unborn child.

The treatment of choice for Madam S. was the use of positive airway pressure.

Initially, she was apprehensive about using the continuous positive airway pressure (CPAP) machine, fearing adjustment issues and inconvenience to her family.

The machine sends pressurised air through the nose and prevents the soft tissue in the throat and tongue from closing up.

After undergoing counselling, she decided to give it a try for a month.

Patients with OSA who are suitable to use the CPAP will experience an immediate improvement in their sleep and daytime functions.

Some patients take about a week to get used to wearing a mask and using the machine, while others may take longer to adapt.

In Madam S.'s case, the pressure from the machine disturbed her sleep. She has allergic rhinitis that was not well-controlled despite being given medication. Therefore, she decided to go for surgery to relieve her nasal obstruction

before trying the positive airway pressure again.

The procedure reduced the size of the structures in the nose that can obstruct airflow, and straightened the partition wall between her nasal cavities. This allowed her to breathe more easily.

After the procedure, she was able to tolerate the positive airway pressure.

When Madam S. saw me for her follow-up review, she was very happy. She can concentrate better at work, and no longer needs as much coffee. More importantly, she was no longer plagued by choking sensations and breathlessness. In essence, she got her breath and life back.

  • Dr Toh Song Tar is the director of the sleep disorders unit and consultant in the department of otolaryngology at SGH.
A version of this article appeared in the print edition of The Straits Times on November 24, 2015, with the headline 'Obstructive sleep apnoea in women can be overlooked DocTalk'. Print Edition | Subscribe