SIRT1 and Autoimmunity: Notably, middle-aged patients with inflammation exhibited lower SIRT1 levels (WMD, −0.85 ng/ml; 95% CI −1.47, −0.22 ng/ml; P= 0.008; I2= 95.4%), while groups characterized by East Asian descent, plasma studies, autoimmune conditions, and musculoskeletal disorders showed higher levels.