With sleep apnoea, your air supply is continually interrupted, causing blood oxygen levels to plummet. You then stir, gasping, trying to breathe. This can happen hundreds of times a night, and the ill-effects are many and severe.
Sleep is marked by dynamic changes throughout the body. It’s made up of different phases, and as you move through them, your breathing, blood pressure and body temperature will all fall and rise. Tension in your muscles mostly stays the same as when you are awake – except during REM phases, which account for up to a quarter of your sleep. During these, most major muscle groups ease significantly. But if your throat muscles relax too much, your airway collapses and is blocked. The result is obstructive sleep apnoea – from the Greek ápnoia, or "breathless".
With sleep apnoea, your air supply is continually interrupted, causing blood oxygen levels to plummet. You then stir, gasping, trying to breathe. This can happen hundreds of times a night, and the ill-effects are many and severe.
Apnoea itself puts puts massive load strain on the heart, as it races to pump blood more quickly to compensate for the lack of oxygen. Fluctuating oxygen levels also cause plaque to build up in the arteries, increasing the risk of cardiovascular disease, hypertension and stroke. In the mid-1990s, the US National Commission on Sleep Disorders Research estimated that 38,000 Americans were dying every year of heart disease worsened by sleep apnoea.
There’s also growing evidence that the condition affects glucose metabolism and promotes insulin resistance – leading to type 2 diabetes – and encourages weight gain.
Then there’s the exhaustion of never having a full night’s sleep, which is associated with memory loss, anxiety and depression. Lack of sleep also causes inattention that can lead to traffic accidents. A 2015 study of drivers in Sweden found that those with sleep apnoea are 2.5 times more likely to have an accident than those without. It also fuels absenteeism, and people with apnoea are fired from their jobs more frequently than those without.
One study found that people with severe sleep apnoea were, all told, three times as likely to die during an 18-year period as those without.
But, as with smoking during the first decades after it was discovered to be lethal, there’s a disconnect between the harm that the condition causes and the public’s perception of it as a threat. “They fail to link sleep apnoea with its many serious co-morbidities,” says a report commissioned by the American Academy of Sleep Medicine, which estimates around 12% of its population suffer silently – but an alarming 80% go undiagnosed. This prevalence is also found globally: nearly a billion people in the world suffer from the condition according to a 2019 study.
Research is now scrambling to catch up with this largely undiagnosed killer. Medical science has been working overtime to find a solution, from in-depth studies of hypoxia – how the body reacts to lack of oxygen – to new types of surgeries and appliances for treating the condition. Of the billion or so people across the globe struggling with sleep apnoea – most probably not even aware of it, never mind receiving treatment.
While there are enduring risk factors for sleep apnoea – such as obesity, a large neck or large tonsils, a small jaw, or getting older – it doesn’t present itself until after an individual falls asleep. The only way to diagnose it is to monitor someone’s sleep.
Or just (OSA) is defined as the cessation of airflow during sleep preventing air from entering the lungs caused by an obstruction. These periods of 'stopping breathing' only become clinically significant if the cessation lasts for more than 10 seconds each time and occur more than 5 times every hour. OSA only happens during sleep, as it is a lack of muscle tone in your upper airway that causes the airway to collapse. During the day we have sufficient muscle tone to keep the airway open allowing for normal breathing. When you experience an episode of apnoea during sleep your brain will automatically wake you up, usually with a very loud snore or snort, in order to breathe again. People with OSA will experience these wakening episodes many times during the night and consequently feel very sleepy during the day: they have an airway that is more likely to collapse than normal.
People with sleep apnoea may complain of excessive daytime sleepiness often with irritability or restlessness. But it is normally the bed partner, family or friends who notice the symptoms first. Sufferers may experience some of the following:
Remember, not everyone who has these symptoms will necessarily have sleep apnoea. We possibly all suffer from these symptoms from time to time but people with sleep apnoea demonstrate some or all of these symptoms all the time.
OSA can range from very mild to very severe. The severity is often established using the apnoea/hypopnoea index (AHI), which is the number of apnoeas plus the number of hypopnoeas per hour of sleep - (hypopnoea being reduction in airflow). An AHI of less than 10 is not likely to be associated with clinical problems. To determine whether you are suffering from sleep apnoea you must first undergo a specialist 'sleep study'. This will usually involve a night in hospital where equipment will be used to monitor the quality of your sleep. The results will enable a specialist to decide on your best course of treatment. The ultimate investigation is polysomnography, which will include:
This is a very expensive investigation, with few centres able to offer it routinely for all suspected sleep apnoea patients. A 'mini' sleep study is more usual, consisting of pulse oximetry and nursing observation. Home sleep study is becoming more popular.
There are several forms of treatment for sleep apnoea. In mild and moderate cases weight loss and the use of mandibular advancement devices can be wholly successful. In moderate and severe cases mandibular advancement device or nasal continuous positive airway pressure (CPAP) are normally prescribed. CPAP is the gold standard treatment for OSA.
OSA is the commonest form of sleep apnoea, (about 4% of men and 2% of women) but there is also a condition called Central Sleep Apnoea (CSA). This is a condition when the brain does not send the right signals to tell you to breathe when you are asleep. In other words the brain 'forgets' to make you breathe. It can also be associated with weakness of the breathing muscles. The assessment for CSA is often more complicated than for OSA and the treatment has to be carefully matched to the patient's requirements. There is also a condition called Mixed Sleep Apnoea that is a combination of both obstructive and central sleep apnoea.
Overeating and/or lack of exercise leads to an increase in fat around the throat. If you have a collar size of 16½ inches or greater, you may not have the muscle tone needed to keep the airway open sufficiently at night to allow normal breathing, and the narrow airway is more likely to vibrate. A person with a short fat neck is at an increased risk of snoring. Excess body fat seems to be more of a problem for men than women. Men tend to get fat around their necks and waists, whereas women seem to put on weight around the thighs. In women, the cross sectional area of the upper airway is greater and the airway walls may be more rigid and therefore less prone to yield to pressure. As a result, collapse of the airway is resisted when muscle tone falls during sleep. This means that women are less likely to snore than men. However, this situation very often changes for women following the menopause. Like men, as women get older their muscle tone tends to diminish and they put on more weight. By the time women have reached the age of 70 they are just as likely to be snorers as men of the same age.
Being overweight by just a few kilograms can be the cause of your snoring. If you have fatty tissue around your neck you will find that during sleep it squeezes the airway and prevents air from flowing in and out freely.
Weight loss with accompanying fat reduction will certainly help to alleviate snoring. However, weight loss cannot be achieved by diet alone, it must be accompanied by a sensible exercise programme.
Alcohol travels to all areas of the body and slows the brain's responses, causing the muscles to relax even more than during a normal night's sleep. Alcohol also acts as a depressant. The added relaxation of the musculature causes the oropharynx to collapse more readily causing further snoring. Additionally alcohol can induce obstructive sleep apnoea (where breathing stops for short periods during sleep) in individuals who are otherwise just snorers. This does not mean that you have 'clinically recognised sleep apnoea' but, when you have been drinking alcohol and your sleep is interrupted by periods of not breathing, you should be aware that if you do not modify your lifestyle, this condition will worsen. It is very much more difficult to treat sleep apnoea than it is to treat simple snoring.
Alcohol also causes nasal airway irritation and congestion that increases the airway resistance when breathing. The consumption of alcohol affects every organ and system in the body. It can damage heart tissue and elevate blood pressure. It also has a high calorie content, and people who are heavy drinkers are often overweight.
If you cannot stop drinking you can modify the effects by having your last drink at least 4 hours before you go to bed. This will give your body sufficient time to reduce the effects of the alcohol and help you to sleep without snoring.
Whilst most people have sufficient muscle tone to prevent the airway from collapsing during sleep this situation may alter if you are taking sedatives. So, if you are taking any medication that has a sedating effect, ask your doctor for a non-sedating alternative. Naturally, you should never stop taking prescribed medicines without your doctor's consent.
Cigarette smoke irritates the lining of the nasal cavity and throat causing swelling and catarrh. If the nasal passages become congested it is difficult to breathe through your nose because the airflow is decreased. The likelihood of snoring increases as more cigarettes are smoked per day because the congestion increases with each cigarette. Even passive smoking can cause inflammation of the nose and throat passages, thus increasing the risk of snoring. Children of parents who smoke are more likely to be affected by snoring than children of non smoking parents. If you cannot stop smoking you can modify the effects by having your last cigarette at least 4 hours before you go to bed. This will give your body sufficient time to reduce the effects of the cigarette smoke and help you to sleep without snoring.
Body position plays an important role during sleep and can often make the difference between having a good night's sleep or not. For snorers and individuals who suffer from obstructive sleep apnoea (OSA), this is a particular problem as several studies have found that individuals who sleep in the supine position (on the back) are more likely to snore or have increased apnoeas than those who sleep in the lateral position (on the side).
The physiological mechanism for this is most probably due to the effects of gravity on the upper airway. When sleeping in the supine position, gravitational forces increase the tendency for the tongue and soft palate to fall back into the throat. This creates a narrowing of the airway and the likelihood of airway obstruction that leads to a number of breathing abnormalities. The airway tends to be more stable in the lateral position and less likely to collapse.
Individuals who suffer 'retrognathia' (receding chin) tend to snore when sleeping on their back. The unusually shaped jaw pushes the structures of the upper airway towards the back of the throat, narrowing the airway so that snoring occurs.
Snoring and apnoea events seem to be more numerous and more severe in the supine position than in the lateral position. One study demonstrated that more than half of their OSA patients had twice as many apnoeas in the supine position than in the lateral position. Interestingly, lateral positional OSA patients are reported to be thinner and have less severe apnoea than supine positional patients. Similarly, lateral snorers are reported to have less severe snoring than those who sleep on their back.
The clinical evidence, regardless of opinion, is unanimous in suggesting that both sleeping position and sleep stage have a considerable impact on both snoring, sleep apnoea and other sleep disorders. Although it would seem desirable to prevent snorers from sleeping on their back, in practice this is rarely achieved. Most studies have confirmed that positional therapy is ineffective and therefore physical therapy such as Mandibular Advancement Therapy will have more beneficial effects.
Sleep stage seems to have more of an effect on snoring independent of body position. Sleep stage affects snoring time and intensity. However, there are differing opinions as to what stage of sleep is of more significance. Some studies report snoring and apnoeas are more prominent in SWS (slow wave sleep), followed by Stage 2 and least in Stages 1 and REM (rapid eye movement). Other studies report snoring and apnoeas are more prevalent during REM sleep. One study reported a higher prevalence of continuous snoring in SWS than in REM and concluded that this could be due to a higher airway resistance in SWS or to the regularity of the breathing pattern. During Stages 1 and 2 of sleep, breathing is frequently periodic and in REM it is irregular with more pauses. Consequently, during light and REM sleep, the incidence of respiratory arrhythmias (changes in breathing pattern) would be high but continuous snoring would be unlikely.
It is thought that sleep position may also have an effect on individuals who suffer sleep bruxism (teeth grinding). In one study, patients were found to have averaged 19 clenches per hour in the supine position as opposed to 15 clenches in the lateral position. This study also found that clenching was associated with sleep stage. Patients who slept in the lateral position had a decrease in the amount of Stage 2 sleep (and an increase in SWS & REM) that resulted in less clenching activity.
Allergies and in particular allergic rhinitis are increasing in prevalence and currently affect between 10-25% of the population. The most common symptoms include: nasal congestion, rhinorrhoea, itching, postnasal drip and sneezing. However, daytime sleepiness, disrupted sleep at night, fatigue, headache, decreased cognitive performance and malaise can also be the consequence of allergic rhinitis but these symptoms are not always recognised as being associated with allergy.
Impaired sleep not only causes daytime somnolence and fatigue but can decrease our productivity, increase our risk of accidents, alter our mood and affect our quality of life. Until now, it has not been easy to prove a direct cause and effect relationship between rhinitis and impaired sleep. However, a recent study by Fisher et al (2005) comparing allergic rhinitis patients with controls, found statistical evidence suggesting that daytime sleepiness and quality of life correlated with the severity of rhinosinusitis. The research also found that for those individuals who suffered allergic rhinitis when sleeping in the supine position (on the back), the congestion in their nasal airway increased. This was particularly evident during the early hours of the morning, which affected their circadian rhythms and consequently their sleep quality.
Congestion in the nasal airway can lead to sleep disordered breathing and snoring. From a questionnaire based study of 5000 subjects who frequently suffered rhinitis symptoms, it was found that they were significantly more likely to be snorers, have non-restorative sleep and excessive daytime sleepiness. The study also found that subjects with nasal congestion were almost twice as likely to have moderate to severe sleep disordered breathing than normal subjects. Statistical findings similar to the previous study found that both nasal congestion and rhinitis were significant factors in sleep disruption, especially when sleeping on the back, with all symptoms being worse in the early morning hours.
Respiratory allergy is the result of nasal hypersensitivity or hyperactivity. The lining of the nose and throat swells which prevents correct breathing through the nasal airway and is often worse at night. Symptoms are typically the same as those of allergic rhinitis and can have similar devastating effects on quality of life.
Known causes of allergic rhinitis and respiratory allergy include: dust particles, tobacco smoke (including passive smoking), feather pillows & bedding, dung of house dust mite, pet hair, indoor plants & flowers, perfumes, some household cleaners and paint smells.
There are many treatments for allergic symptoms and the best treatment of all is to prevent or avoid the offending allergy. For example, barrier bedding is readily available in high street shops and will prevent house dust mites from entering your pillows and bedding. Tobacco smoke is a common allergen and can affect not only the smoker but all those who inhale it. It has long been established that children of smoking parents are twice as likely to snore as those from non-smoking families.
The anti-inflammatory and astringent properties of herbal sprays such as Rhynil will help reduce the symptoms of nasal congestion and can be used on a long-term basis. But what if you don't know what is causing your allergy? It may be worth trying a simple home test allergy kit to determine the cause.
Nasal stuffiness is another common reason for mouth breathing, because we tend to breathe with our mouths open to compensate for not being able to breathe through our noses. It is essential that you find out what is causing the nasal stuffiness and treat it. Using Rhynil, which is safe for long-term use, can reduce nasal congestion and catarrh.
You may also like to try steam inhalation. This traditional remedy is very worthwhile. Alternatively, if your nasal stuffiness persists you may find antihistamines can be very useful. Ask your GP or pharmacist for advice.
Rhynil is made from the plant known as Euphrasia Oficinalis or Eyebright. This plant was originally used as a treatment for eye problems but in recent years it has been widely used in the treatment of conditions such as catarrh, infectious and allergic conditions affecting the sinuses and nasal passages, hay fever and upper respiratory tract infections.
Individuals who suffer any condition that affects the nasal passages will find it difficult to breathe at night. This encourages mouth breathing and snoring as a consequence. The properties of Eyebright help relieve nasal congestion and related symptoms making nasal breathing easier.
Although there is very little published clinical data on the efficacy of Eyebright in reducing snoring, BSSAA has undertaken a total of 4 trials on its efficacy. The results of the trials concluded that 70% of subjects found a very definite improvement in reducing snoring, 20% found no improvement and 5% stopped the trial due to ill effects (2 subjects reported epistaxis (nose bleed), 1 reported vivid dreams, although these conditions cannot necessarily be attributed to the treatment).
Rhynil is recommended for individuals whose snoring originates from the soft palate, mouth breathing or nasal congestion.
Rhynil is currently our Best Selling Snoring Product
If you are a 'mouth breather' and sleep with your mouth open you will probably snore. When we breathe in through the nose the air passes over the curved part of the soft palate in a gentle flow into the throat without creating unnecessary turbulence. When we breathe in through the mouth however, the air hits the back of the throat 'head on' and can create enormous vibrations in the soft tissue.
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We probably do not think about 'how' we breathe as it is a natural function and happens anyway. However, how we breathe is important especially at night.
During sleep we are designed to breathe through the nose. If for any reason nasal breathing is not possible our body's self-preservation mechanism forces us to breathe through the mouth. There are several reasons as to why some people find it difficult to breathe through the nose during sleep.
These features increase nasal resistance, commonly known simply as 'nasal resistance'. Nasal resistance may be a contributing factor in the occurrence of sleep disordered breathing, upper airway resistance syndrome (UARS), snoring and obstructive sleep apnoea (OSA). Madronio et al (2004) studied a group of 43 subjects and reported that those who were nocturnal 'mouth breathers' tended to experience more apnoea events than those with predominantly nasal breathing. They also concluded that mouth breathing may increase the risk of upper airway collapse as the respiratory muscles are 'route dependent' and mouth breathing interferes with the normal passage of air passing into the lungs. If oxygen is unable to be delivered around the body and in particular to the brain during sleep, sleep quality is affected and may lead to the condition known as excessive daytime sleepiness (EDS).
This relationship between nasal resistance and sleep disordered breathing was first noted in the 1800's when it was concluded that by dilating the nostrils these undesirable effects could be relieved (Rappai M 2003). Since then many studies have concluded that the use of nasal dilators can improve both nocturnal breathing and sleep quality for individuals who are affected by nasal resistance.
The scientific principle behind nasal dilation is based on physiology and physics and the effect is to dilate the air passage of the nose and to stiffen the nasal wall. Both mechanisms reduce nasal resistance and allow higher flow of air.
In 1988 Professor Petruson of Sweden invented a simple nasal dilator called Nozovent. Over the years it has proved to be one of the most popular and easy to use devices to enhance nasal breathing. This device is not just for snorers but can be used by anybody who suffers from nasal resistance.
The vibrations produced by prolonged and heavy snoring injure the airways and affect the upper airway muscles (pharyngeal, laryngeal, tongue and soft palate). Vibrations induced by snoring may also damage the nerves of these muscles and interfere with blood supply. In normal individuals these muscles support the airway and prevent it from collapsing, but due to the damage caused by snoring it is thought that the upper airway muscles are more likely to suffer from fatigue in snorers and are more prone to collapse.
If you are a 'tongue base snorer', this means that you snore because your airway is liable to vibrate at the base of the tongue. Turbulent air is trying to get into your lungs through this restricted airway and in doing so it vibrates the tissues of the tongue. The tongue may partially or completely block the airway preventing you from breathing. This is termed apnoea which means 'without breath'.
By using a Mandibular Advancement Device (MAD) you can gently bring your lower jaw forward and keep your tongue away from the back of your throat, thus preventing the obstruction.
Clinical studies consistently show that MADs are an acceptable form of treatment in the long term for patients with tongue base snoring and mild/moderate sleep apnoea. Patients from one study categorized the device as fair or good after 10 years of wear. Seventy percent of these patients were wearing the device every night for 6 hours.
Controlling snoring with a MAD will not only reduce snoring but will also improve general health and wellbeing. One study reported significant changes to snoring, breathing pauses, daytime sleepiness, concentration, night time sleep quality, work efficiency, tiredness, general health and mental status, following MAD treatment. Similar improvements in health and wellbeing were also reported by bed partners.
Many snorers using a MAD for the first time believe that it will interfere with their sleep. However, these fears are unfounded. Studies, in which sleep architecture has been monitored, clearly show an improvement in sleep quality and a significant decrease in sleep fragmentation.
Around 30% of patients using a MAD suffer minor side effects, although this does not appear to influence compliance. The majority of patients indicate that they find the device comfortable or only slightly uncomfortable. The most frequent side effects are excessive salivation, teeth discomfort and jaw discomfort. The frequency and severity of side effects are undoubtedly affected by the type of appliance, wear time, degree of protrusion and care taken in the fitting process.
It has recently been found that MADs are also suitable for individuals whose snoring originates from the soft palate. The researchers found that snoring originating from palatal flutter was significantly improved following MAD use. They concluded that not only does a MAD increase the airway dimension at the tongue base but also at the level of the soft palate.
You may find that your snoring is not confined to a single cause but is multi-factorial. For example, you may be snoring because you are sleeping with your mouth open. But the reason you habitually breathe with your mouth open may be because you have an allergy that is causing nasal stuffiness and preventing you from breathing through your nose. In this situation you will need to address both the nasal stuffiness and the mouth breathing in order to control your snoring.
Snoring and sleep apnoea are generally considered to be conditions predominantly affecting men. The basis for this assumption is made purely on early epidemiological studies and clinical research conducted on male patients. Studies from the early 1970s and 1980s suggested that the male:female ratio for sleep apnoea was around 60:1. However, more recent research has recognised that snoring and sleep apnoea in women is not as rare as was once thought. More recent studies on general populations have reported male:female prevalence ratios for sleep apnoea are around 2:1.
But despite these findings, the greater prevalence of snoring and sleep apnoea in men still tends to promote an unintentional 'selection bias' for referral. Some studies have found that men are twice as likely to be referred for a sleep study than women. Many GPs rely on self reported snoring and sleep apnoea, and because men are more likely to seek help about snoring from their GP, they are more likely to receive an early referral for a sleep study. Nearly half of women snorers do not report their symptoms to their GP, often due to embarrassment or shame, but they do tend to be heavier users of healthcare resources prior to a diagnosis being confirmed.
The few population studies that have included women, show undiagnosed sleep apnoea is far more prevalent in women than men. One study found that sleep apnoea was undiagnosed in more than 90% of women with moderate to severe sleep apnoea. One hypothesis that has been put forward is that because women often present with symptoms that differ from the current clinical indications for the evaluation of sleep apnoea, the condition may be missed or misdiagnosed. For example, in one study, nearly half of the female patients did not report apnoea events, choking or restless sleep to their GP but all the males did.
A study comparing health care costs among patients with snoring and sleep apnoea, found both sexes incur nearly double the healthcare costs of normal patients, but women incur significantly more costs than men. Both sexes have considerably more consultations with specialists and women have nearly 50% more visits compared to men. Similar figures have been found for drug costs, with women being prescribed antidepressant drugs three times more frequently than men. The results of the study concluded that snoring women tend to have more minor illnesses and atypical symptoms while men with the same severity of snoring have more chronic and fatal diseases.
The symptoms of snoring and sleep apnoea have an adverse effect on neurological and psychological function resulting in poor work performance, difficulty in concentrating, memory impairment, headache, nausea, impotence and decreased libido. These symptoms have the same effect on both men and women.
Typical symptoms of sleep apnoea, snoring, apnoeas, choking and restless sleep, are similar in both men and women. However, snoring women tend to present with additional symptoms that may be misinterpreted to represent other conditions. Atypical symptoms such as daytime fatigue, headaches, insomnia, tension, depression and the use of sedatives are more frequent in women than men and may divert GPs and clinicians to diagnose and treat for other conditions. For example, because women are more likely to report insomnia and depression they are more likely to be treated for these symptoms rather than the underlying cause of their sleep apnoea.
Nearly half of all middle aged men snore, but women tend to snore later in life with an increased prevalence after menopause at around 60-64 years of age. Additionally, snoring sound in women is less intense therefore snoring may not be such an issue for younger women.
Obesity seems to be the dominant factor for the occurrence of sleep apnoea in women when matched with males for age and degree of sleep disturbance. One study reported that women had a higher BMI (body mass index) than men at each level of RDI (respiratory disturbance index). There is evidence that obesity is greater in premenopausal women compared to postmenopausal women with sleep apnoea. It has also been reported that premenopausal women have more severe apnoea compared to postmenopausal women with the same BMI. It was reported in the same study that women who snore but without apnoea were not obese. However, morbid obesity occurs twice as often in women compared to men and since obesity is the main risk factor for the development of sleep apnoea, one might predict that women should have sleep apnoea more frequently than men. But evidence supports the opposite. Perhaps the argument for obesity as a risk factor for sleep apnoea in women is not obesity per se, but rather a matter of fat distribution.
There is a relationship in overall neck size and airway obstruction, and men have a higher proportion of fat around the neck area compared to the rest of the body, than do women. Men tend to have a greater volume of fat in the soft palate and the upper part of the tongue whereas women tend to have greater fat deposition in the lower part of the airway. Women also tend to have less upper airway anatomical abnormalities and require greater fat infiltration before they have a reduction in airway space.
Craniofacial anatomy could be an important factor in the prevalence of snoring and sleep apnoea. Both men and women who snore or have sleep apnoea have differences in craniofacial anatomy compared to the normal population.
It is known that men have significantly larger airways and pharynx than women. But despite this fact, their pharynx is more prone to collapse. Although the airways of women are narrower they are stiffer and less likely to collapse. Men also have less muscle tone in their upper airways making them more vulnerable to snoring and sleep apnoea.
Female hormones may have a protective effect on the upper airway dilator muscles as they are believed to protect the airway from obstructing during sleep. However, hormone replacement therapy (HRT) in postmenopausal women has yielded conflicting results. Some studies found modest improvements in snoring and sleep apnoea with oestrogen alone, whilst others found better improvements with both oestrogen and progesterone. Some studies however, found no improvements at all.
Testosterone on the other hand, has been found to increase upper airway collapsibility and the consequent risk of developing snoring and sleep apnoea. An interesting study on males with gonadal dysfunction found that when they were treated with testosterone replacement their snoring and sleep apnoea doubled in severity during the treatment. Similarly, it was reported that women with polycystic ovary syndrome (characterised by an excess of male hormones) had a 4-fold increase in the risk of snoring and sleep apnoea. This may explain in part why there is a male predominance in snoring and sleep apnoea.
Excessive daytime sleepiness, fatigue, decreased libido, depressed mood, headache, impaired concentration and obesity are all symptoms associated with snoring and sleep apnoea. But they are also symptoms of hypothyroidism. Hypothyroidism in snoring women is statistically higher than it is in men. This may be another reason why snoring and sleep apnoea in women are confused or misdiagnosed. In patients with hypothyroidism, sleep disordered breathing appears to be common, yet in patients with snoring or sleep apnoea, hypothyroidism is very uncommon. The reasons why this should be are still unclear. There does appear to be a positive link between obesity and hypothyroidism. In one study with obese individuals, their snoring and sleep apnoea reduced significantly following hormone therapy, as did their BMI. Thyroxin therapy was also given to snorers who were not obese, and similar results were obtained with a reduction in their snoring and excessive daytime sleepiness. This connection between hypothyroidism and snoring and sleep apnoea is interesting and is worthy of further research.
There is an increasing interest in the association between snoring, sleep apnoea and diabetes mellitus. Diabetes is often associated with snoring and sleep apnoea, predominantly in overweight males. However, one study of women aged 25-79 years found diabetes in snoring women independent of age, obesity or smoking status. Snoring women were twice as likely to suffer diabetes than non- snoring women.
Both diabetes and snoring and sleep apnoea are influenced by sexual hormones. Snoring and diabetes often increase during pregnancy, after the menopause and in women with Polycystic Ovary syndrome. The sleep deprivation and cyclic decreases in oxygen levels that occur as a result of snoring and sleep apnoea tend to increase insulin levels. It has been suggested that this may be the link between snoring and diabetes as one study reported that insulin sensitivity improved following treatment for snoring and sleep apnoea.
In summary, two factors seem to be prominent; hormones and airway resistance. The influence of hormones may be the most important determinant in the differences between men and women, but airway mechanics and collapsibility seem the most likely mechanism that would explain the predominance of snoring and sleep apnoea in men.
We should be aware of the additional atypical symptoms in women; of fatigue, headaches, insomnia and depression, and of the importance of further investigation to prevent under detection and under treatment of snoring and sleep apnoea.