There is a frequently overlooked factor that can cause an acute increase in the concentration of uric acid in the blood as well as increased likelihood of its precipitation as MSU (monosodium urate or uric acid crystals. See, Gout Basics for background). That factor is the reduction of the concentration of oxygen in the blood, which occurs in an individual suffering from sleep apnea.

Sleep apnea is the repeated cessation of breathing for many seconds at a time during sleep, when the muscles lining the airway relax enough to allow it to close, until the brain jolts them to reopen. The resulting reduction of oxygen in the blood causes the cells in the body to undergo a process of disintegration, which leads to their generation of excess uric acid. Once the uric acid is formed, the process is irreversible, even when breathing restarts. With each apneic period, more and more uric acid is fed into the blood, faster than the kidneys can dispose of it. Furthermore, the increased ratio of carbon dioxide to oxygen in the blood makes the blood more acidic, so that its ability to hold uric acid in solution is reduced and MSU is more likely to precipitate. These processes were described in medical journal literature about twenty years ago, and subsequent literature has confirmed that sleep apnea leads to excess uric acid in the blood and in the urine.
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