Conditions
If insomnia is making your waking life a nightmare, you may have obstructive sleep apnoea, one of the sleep disorders that are becoming more common.
Sleep specialist Dr Irshaad Ebrahim, who runs sleep clinics across the world, including one at Mediclinic Constantiaberg, sheds some light on disorders that reveal themselves after dark.
How common is insomnia?
As many as one-third of patients seen in the primary care setting may have occasional difficulties in sleeping, and 10% of those may have chronic sleep problems. About 30 to 40% of adults indicate some level of insomnia within any given year, and it’s severe in about 10 to 15% of cases.
The prevalence of insomnia increases with age and is more common in women, the most chronically sleep deprived members of society. Though eight hours of sleep are recommended, women between 30 and 60 average just under sevem hours of sleep per night during the week. By definition, insomnia is a difficulty in falling asleep and/or staying asleep and/or early morning waking, plus daytime symptoms such as tiredness, lethargy, irritability, difficulty concentrating and so on. If you have these symptoms, discuss them with your doctor. In terms of what constitutes insomnia, one to three wakings is considered within the norm – as long as you don’t feel sleepy the next day. An easy way to calculate your sleep efficiency is to divide the actual sleep time by the time in bed (sleep opportunity). This should be as close to one (i.e. 100%) as possible.
If insomnia comes from difficulty breathing at night, could it be obstructive sleep apnoea?
Yes. Obstructive sleep apnoea (OSA) is a disorder in which there are breaks or pauses in a person's breathing during sleep. Most people who have OSA also snore, but not all snorers have OSA. With OSA, a person can have breathing interruptions (apnoeas), which last for 10 seconds or more, when the respiratory airway narrows so much that it closes. The brain reacts by briefly waking the subject, causing the airways to reopen and breathing to continue. This can happen up to several hundred times during the night, resulting in sleepiness and impairment of daytime function. OSA may also be associated with irregular heartbeat, high blood pressure, heart attack and stroke.
How is OSA diagnosed and treated?
Diagnosing OSA needs to be done in a sleep centre and it needs at least one nocturnal polysomnogram (PSG), which measures brain waves, eye movements, muscle tone, heart rate, oxygen levels, heart rhythm and breathing movements during sleep. The most effective treatment is using Positive Airway Pressure (CPAP), where a mask is worn over the nose during sleep. Nasal CPAP provides a pressure splint to the upper airway, allowing the person to breathe (and hence sleep) normally. The airflow required is determined through testing during sleep, also using an overnight PSG. Several alternatives to CPAP have also become available in South Africa from VentMed Africa.
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