Studies show that gout appears almost three times more often at night than at other times of the day. There are several hypotheses to explain why the attacks appear at night:
- The body temperature drops from 37.5 to 36.4 degrees during the night, which leads to a higher risk of crystallisation, which in turn can lead to the attack.
- The relative dehydration that the body undergoes at night and the lying down position could lead to this increased risk.
- The decrease in cortisol in the blood during the night could also deprive the body of its protective effect, as is the case for patients with arthritis.
- There is also a possible link with sleep apnoea. The lack of oxygen would lead to a greater release of purines, which are metabolised by uric acid. More than half of the patients with sleep apnoea suffer from hyperuricaemia.
For nighttime gout attacks, a common treatment is a continuous positive airway pressure (CPAP), or another device that increases oxygen intake. An increase in oxygen intake can lower the risk of developing gout attacks and may also reduce uric acid production.