There are multiple studies linking circulating BDNF concentration to type 2 diabetes in humans and mice (Krabbe et al., 2007; Sha et al., 2007; Li et al., 2016; Murillo Ortiz et al., 2016) as well as in type 1 diabetic patients (Tonoli et al., 2015). Here, BDNF is linked to type 2 diabetes mellitus.