Similarly, BDNF concentrations in healthy individuals typically range 32.69 ± 8.33 ng/mL (129), but both T1D and T2D patients exhibit lower circulating BDNF levels, suggesting that BDNF deficiency may contribute to impaired bone remodeling and neuro-metabolic dysfunction in diabetes (130, 131). Here, BDNF is linked to type 1 diabetes mellitus.