SIRT1 and rheumatoid arthritis: Tan et al15 identified a positive correlation between SIRT1 and disease activation markers in patients with rheumatoid arthritis, indicating that SIRT1 may be associated with the proinflammatory status and its levels could fluctuate either as a result or cause of worse disease prognosis in rheumatoid arthritis.14,15 However, Wu and colleagues observed that SIRT1 activity was diminished in the peripheral blood of rheumatoid arthritis patients relative to healthy controls.