Sleep disorders and gout frequently co-exist in adults, an Australian study has confirmed.
South Australian researchers have found that people with obstructive sleep apnoea are almost three times more likely to have gout than people without OSA.
In their analysis of findings from a national sleep disorders survey of 1948 people, they found that 124 (6.4%) reported having sleep apnoea diagnosed by polysomnography, and 126 respondents (6.5%) had gout. A further 190 participants (9.8%) had symptoms suggestive of sleep apnoea without a formal diagnosis
After adjustment for confounder such as age, BMI, sex, alcohol intake and the presence of arthritis, a participant with diagnosed OSA was 2.6 times more likely to have gout.
Similarly, a diagnosis of gout was 2.8 times more likely in respondents with sleep apnoea symptoms suggesting possible OSA.
The study, led by Dr Julia New-Tolley and Professor Catherine Hill of the Rheumatology Unit, The Queen Elizabeth Hospital, Adelaide, also found a possible relationship between gout and patient reported sleep problems.
People with gout were also 2.5 more likely to have restless legs symptoms or periodic leg movements of sleep (15% vs 6.7%) and also had higher rates of insomnia and worry about sleep (39% vs 29%) compared to people without gout.
The study investigators noted that previous research had shown that serum uric acid levels were higher in people with OSA than in controls. The association might be explained by intermittent airway obstruction during sleep leading to hypoxia, and resulting in increased serum uric acid via alteration in cellular metabolism, they wrote in BMC Rheumatology.
However, the mechanism behind the association between gout and restless legs syndrome was unclear, they added, noting that a recent study of patients with restless legs syndrome showed reduced urate levels compared to controls.
Nevertheless, the study findings had shown that sleep disorders and gout were common and frequently comorbid in the Australian population, they said.
“Sleep apnoea and gout are both associated with significant cardiovascular morbidity and mortality, but are also treatable,” they wrote.
“Given the prevalence of gout and the substantive financial burden of sleep-related conditions and flow on effects including productivity, employment, accidents and well-being, our findings highlight the importance of identifying and managing sleep problems in patients with gout,” they concluded.