FNDC5 and type 2 diabetes mellitus: Moreover, Hou et al. evaluated the role of irisin using the same diabetic model and T2D patients’ samples, reporting that with respect to healthy subjects, it was evident that the reduced serum irisin levels and BMD of L1-L4 lumbar spine, total hip, femoral neck, and Wards in postmenopausal T2D patients, further diminished in osteoporosis T2D patients [66].