Interestingly, we found that one year after pegvisomant start, there was a significant correlation between the delta IGF-I (n = 274) and delta glucose (n = 272), in the whole cohort, with a linear correlation coefficient r = 0.21 (p = 0.0008), as well as in both the DM and no-DM groups (r = 0.27; p = 0.007, and r = 0.20; p = 0.01, respectively). Here, IGF1 is linked to diabetes mellitus.