Circadian rhythms in RA

On the contrary, the nocturnal rhythm of MLT shows an earlier peak and a longer peak duration in the early morning in patients with RA than in normal subjects. [...]an imbalance between anti-inflammatory effects exerted by cortisol and proinflammatory effects exerted by MLT during the night seems evident in patients with RA and suggests that this imbalance may have a crucial pathogenic role in RA, and may also drive the circadian rhythm of the clinical symptoms (that is, morning stiffness and pain).