The gout attacks caused by sleep apnea will develop while sleeping. Once the monosodium urate crystals have formed, the body will gradually coat them with a protein compound that hides their chemical composition from the immune system so that the attack doesn't continue for the many months that the crystals remain. If the coating gets ruptured by physical or chemical stress, a new attack will be initiated, which probably will occur during waking hours, and will continue until the rupture is repaired. I recall very clearly how I developed a gout attack years ago while sitting cross-legged on the floor while working on a handyman project at home. I had put too much physical stress on the top of my foot, which is where my overnight gout attacks almost always occurred and where this daytime attack occurred also.
I view sleep apnea as more than a trigger for gout. It is a direct cause. When the oxygen depletion of sleep apnea leads to enough generation of excess uric acid fed into the blood, a gout attack will ensue almost immediately in those people who are genetically predisposed to gout.