These results were in accordance with the published data displaying that the levels of miR-34a expression augmented in obese mice, thus leading to the reduced hepatic NAD+ content and Sirt1 activity via targeting Nampt, which also indicated that diminished Nampt expression contributed to miR-34a-induced hepatic NAD+ insufficiency in obesity [14]. Here, NAMPT is linked to obesity due to melanocortin 4 receptor deficiency.