Do you know if you have sleep apnea? Here’s yet another reason to get checked for obstructive sleep apnea (OSA), the most common type of sleep apnea: A study published online on August 30, 2018, in the journal Arthritis and Rheumatology showed that people with OSA have a higher risk of developing gout, a type of arthritis that causes swollen, painful, and stiff joints. In the follow-up of the study, researchers found that 4.9 percent of OSA patients and 2.6 percent of non-OSA patients developed gout.
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There are two other types of sleep apnea (central and complex) but they were not looked at in this study.
Study Proves Increased Risk for Gout, Both Short-Term and Long-Term
Overall, the risk of gout is greatest between one and two years after the diagnosis of OSA, with risk of onset of gout being more than 50 percent greater among those with sleep apnea compared with those without.
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But this new research shows that the risk remains long after that initial sleep apnea diagnosis. “This increased risk persisted over a longer period of time following sleep apnea diagnosis, those with sleep apnea having approximately 45 percent higher risk of gout compared with those without sleep apnea,” explains Milica Blagojevic-Bucknall, PhD, senior lecturer in statistics at the Arthritis Research UK Primary Care Centre in the Research Institute for Primary Care & Health Sciences at Keele University in the United Kingdom.
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Gout Risk Higher in People With Normal Body Weight — But Why?
The results looked at people with normal body mass index (BMI) and those who were overweight or obese. Interestingly, the risk was higher in those with normal weight. But this is because severity of OSA plays an important part in interpretation of the findings.
“Those with moderate or severe OSA are given CPAP (continuous positive airways pressure) therapy; they are likely to be those who are more obese than those with mild OSA, for whom weight loss, jaw advancement devices, and sleeping position are recommended first line of treatment, with CPAP therapy given only if these fail.
This is perhaps the reason why those with lower BMI have a longer-term risk of gout, as CPAP is very effective and reverses OSA pathology, including improvements in hypertension. Since this risk was highest in people with normal BMI, people experiencing sleep apnea should be aware of the possibility of gout regardless of body mass index,” notes Dr. Blagojevic-Bucknall, adding “further research is needed to establish more firmly the relationship between CPAP and its impact on reduction of risk of gout.”
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Neck and Waist Circumference Are Also Relevant in Sleep Apnea
It should further be noted that in some cases neck and waist circumference, rather than BMI, may be better correlates of sleep apnea as they take into account obesity distribution and are therefore associated with visceral obesity, which is associated with risk of OSA among others, Blagojevic-Bucknall points out.
What Is the Connection Between Obstructive Sleep Apnea and Gout?
The most likely mechanism to explain the association between OSA and gout is that intermittent hypoxia (oxygen deficiency) causes an overproduction of uric acid, which in turn can lead to gout. “This raises the question as to whether correction of hypoxia in sleep apnea by treatment with CPAP lowers serum uric acid levels. This could theoretically both reduce the risk of incident gout and treat existing gout,” according to Blagojevic-Bucknall.
If you think you might have OSA or gout, seek help from a healthcare professional. Without proper treatment, both can lead to further damage.
Related: Sleep Apnea Can Pose Serious Threats to You and Others if It’s Not Diagnosed and Treated
Common Symptoms of Obstructive Sleep Apnea
OSA occurs when the tongue falls back and blocks the airway. Sleep apnea symptoms include the following:
- Intense fatigue and difficulty concentrating during the day
- Loud snoring
- Short periods of breathing cessation while sleeping, followed by waking up suddenly while gasping or choking
- Waking up with a dry mouth, sore throat, or headache
- Depression or irritability
- High blood pressure
- Nighttime sweats
- Decreased sex drive
Some of these you might not be aware of, so if you have a sleeping partner, ask her or him to observe.
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The Diagnosing of Obstructive Sleep Apnea
After ruling out a blockage in your ear, nose, or throat, your physician will probably ask you to take an overnight sleep study, either in a clinic or at home. You will be attached to equipment that will monitor your heart, lung, and brain activity, as well as airflow, body movement, and blood oxygen levels while you sleep.
Signs and symptoms of gout:
- Attacks of severe pain in the affected joint
- Pain continues at a lower level after attack ends
- Joint appears swollen and red, and is tender to the touch
- Movement of the joint becomes increasingly limited
Testing for Gout and Diagnosis of Gout
Your doctor may order the following tests:
- Joint fluid test, dual energy CT scan, or ultrasound to look for the presence of urate crystals
- Blood test to measure the levels of uric acid and creatinine in your blood
- X-rays to eliminate other causes of joint inflammation