SIRT1 and Insulin resistance: Moreover, oscillatory genes in both datasets included NAMPT, KLF11, and GFPT2, the latter controlling the flux of glucose into the hexosamine pathway, tightly linked to hyperglycemia and insulin resistance (Coomer and Essop, 2014). The expression of NAMPT, a key regulator of NAD+ synthesis and muscle maintenance (Frederick et al., 2016), was previously shown to be regulated by CLOCK and BMAL1 in complex with SIRT1 (Ramsey et al., 2009; Garten et al., 2015).