What's the link between sleep apnoea and gout
A study of nearly 16,000 patients with obstructive sleep apnoea (OSA) shows they are twice as likely as people without apnoea to develop gout.
UK researchers drew on a nationally representative database to identify patients diagnosed with OSA between 1990 and 2010, and matched them with 63,000 controls based on age, gender and the GP clinic they frequented.
Over the follow-up period of six years, 4.8% of apnoea patients and 2.6% of patients without apnoea developed gout, a twofold difference in incidence, the researchers reported.
The increased risk of gout was seen in patients with OSA in all categories of BMI, but was highest in those with a normal BMI.
“This suggests that the contribution of OSA to the risk of hyperuricaemia and gout is independent of BMI, and clinicians should consider the possibility of gout in patients with sleep apnoea regardless of obesity,” the authors wrote.
Although it has been shown in previous studies that people with OSA have a higher risk of developing gout in the first year after apnoea diagnosis, the current study showed the risk persisted, with high risk observed in those with normal BMI at 2-5 years post-OSA diagnosis.
The researchers said there was evidence that patients with OSA had elevated serum uric acid levels.
“The intermittent hypoxia present in OSA enhances nucleotide turnover generating purines, which are metabolised to uric acid, providing a biologically plausible mechanism by which OSA predisposes to hyperuricaemia and gout,” they wrote.
More information: Arthritis & Rheumatology 2018; online.