<b>Methods</b>: Eleven subjects with obesity (BMI ≥ 30 kg/m<sup>2</sup>) and six controls without the disease (BMI < 30 kg/m<sup>2</sup>) were enrolled, and SIRT1 was measured in SAT and plasma by ELISA. Here, SIRT1 is linked to obesity due to melanocortin 4 receptor deficiency.