Gout is a common form of arthritis, most often affecting the joints in the hands and feet, caused by a build-up of uric acid crystals, which results in inflammation and pain in these joints. It is believed to affect nearly 3 percent of all adults. Obstructive sleep apnea (OSA) is also thought to affect a similar percentage of adults, although it is suspected to be underdiagnosed due to patient unawareness.
Both conditions are linked to serious comorbidities including metabolic syndrome, hypertension, obesity, insulin resistance, and cardiovascular disease, which is why a group of researchers performed a study to determine whether people with obstructive sleep apnea are more likely to develop gout than those without it.
Using the UK Clinical Practice Research Datalink, the researchers analyzed data on participants with gout and a control group made up of up to 4 participants matched to each individual gout patient based on age, sex, and practice. The participants with obstructive sleep apnea received their diagnosis between 1990 and 2010, with researchers following up until the end of 2015. In total, there were 15,879 participants with obstructive sleep apnea and 63,296 in the control group.
On average, the participants were involved in the study for 5.8 years. Past research has only related obstructive sleep apnea to gout for a period of 1 year after diagnosis. The researchers behind the current study wanted to ensure their results showed both the risk of developing gout in relation to obstructive sleep apnea in the short term and the long term, which is why they extended the follow-up period for their study to nearly 6 years.
Risk of Gout Peaks within First Two Years of OSA
The results of the study confirm the findings of previous research, that obstructive sleep apnea increases a patient’s risk of developing gout by around 50 percent. The findings of this study go beyond the results of the past, which had only determined that OSA increases the risk of gout within one year of diagnosis, to say that the risk of gout incurred by obstructive sleep apnea patients is at its highest during the first two years after diagnosis.
“While there is potential for misclassification of OSA, this diagnosis is unlikely to be made solely in primary care and, as such, will be entered into the patient’s record only after a diagnosis has been made by a respiratory specialist in secondary care. Previous studies have shown that when a GP records a diagnosis of OSA, this diagnosis is usually correct. Therefore, it is likely that those identified as having OSA do indeed have the condition; however, OSA may be unrecognized in some patients,” write the researchers.
Further research will still be needed to fully understand the underlying mechanisms between obstructive sleep apnea and gout, although the researchers behind the current study do offer several hypotheses. There was some relationship between risk of gout and body mass index in the participants with obstructive sleep apnea in this study, but its implications are unclear. Additional studies should also focus on treatments for obstructive sleep apnea and gout and whether these affect the risk relationship between them one way or the other.