Sleep apnea — from the Greek ‘apnea’ meaning ‘without breath’ — is a fairly common condition in which the sleeper’s airway becomes completely blocked when the muscles and soft tissue in their throat relax during sleep and collapse inward.
This causes complete stoppages of breath for short periods, generally tens of seconds, but often up to a minute or more. This can happen many times, even hundreds of times, during the night. In most cases the sleeper is completely unaware of these ‘apneas’ since they generally aren’t fully wakened by them.
It is known that because of these very severe drops in oxygen in the bloodstream, if left untreated, sleep apnea can have life-threatening consequences such as diabetes, hypertension (high blood pressure), stroke, liver and kidney problems, and heart disease.
And, according to one recent study an increased risk of a night heart attack. The study quotes a figure of 12 million American adults affected by sleep apnea, many of them undiagnosed; although the National Sleep Foundation puts the figure at 18 million! The number for the United Kingdom is thought to be between 2% to 4% of the adult population, around 1 million to 2 million adults.
How May Sleep Apnea Be Linked To Gout?
We have known since 1987, as a result of research by Hasday and Grum, that severely reduced blood-oxygen levels during apneas produce a corresponding sharp increase in blood-uric acid levels during the night. Their findings have been confirmed by several other studies since then.
Sleep apnea patients’ body cells begin to disintegrate during an apnea episode — as a result of oxygen starvation — producing uric acid as a result. This happens during each episode so that more and more uric acid is being produced at a rate that the kidneys just cannot handle.
Not only that, the patient’s blood becomes more acidic as blood-oxygen levels reduce, so that it’s harder for the blood to retain uric acid in solution, making it much easier for crystals to form, settle in the joints, and trigger a gout attack.
Also, sleep apnea and gout patients share certain traits that are high risk factors for gout, e.g., obesity, age (largely 40+) and sex (predominantly male). So someone with sleep apnea is inherently at a higher-than-normal risk of gout.
Finally, although it has always been ‘known’ that most gout flare-ups occur during the night and early hours of the morning, a recent study has actually quantified and confirmed it. And, although there is a belief that lower body temperatures during sleep may account in part for this, the connection to sleep apnea now cannot be ignored.
Could Gout Be Linked to Sleep Apnea?
Not only does there seem to be a link between sleep apnea and gout there’s also a plausible link between gout and sleep apnea. A UK study linked gout to a range of sleep problems including sleep apnea and concluded that:
“Gout and sleep problems appear to be associated and clinicians should be aware of the co-existence of these two conditions. Larger prospective epidemiological studies are required to explore causality.”
And, although not trying to associate gout with sleep apnea directly, researchers at the University of Buffalo, USA, tracked blood vessel oxidative damage and blood vessel functioning of 12 sleep apnea patients. Half were given allopurinol — used to reduce uric acid levels in gout patients — and the other half a placebo.
The results of the two week long study showed that those on allopurinol exhibited improved blood vessel function and lower oxidative damage. So, a drug used to inhibit uric acid production in gout patients can do the same in patients with sleep apnea.
Although more research is needed to prove conclusively that sleep apnea ’causes’ gout, there is sufficient to at least ‘link’ sleep apnea to gout: we know that sleep apnea patients’ uric acid levels rise during the night and blood becomes more acidic making it easier for uric acid crystals to form in the joints.
We also know that most gout attacks occur at night and that sleep apnea and gout patients share similar gout risk factors such as obesity, age, and sex.
So, if you suffer from frequent gout attacks, it might be worth speaking to your doctor about getting tested for sleep apnea. Although recurring gout is a very serious condition that certainly needs to be tackled, sleep apnea is even more serious.And as there seems to be some link between the two conditions, gout could well be a sign of that condition.
Some patients who have been diagnosed with both conditions and have had their sleep apnea treated and controlled have reported a corresponding reduction in gout flare-ups, even having them cease altogether.