A negative correlation between FBG levels and TBS has been revealed in previous studies (17, 46) and the possible mechanisms may be related to the dysregulation of IGF-1 in individuals with impaired glucose tolerance (IGT), as already mentioned, and to the accumulation of advanced glycation end products in the organic bone matrix and to low bone turnover in patients with diabetes (46). This evidence concerns the gene IGF1 and diabetes mellitus.