IGF1 and type 2 diabetes mellitus: Although some of the available prospective observational and genetic evidence suggests that higher IGF-I levels might be positively associated with type 2 diabetes [8, 9], ischaemic heart disease (IHD) [9–11], hip and knee osteoarthritis [12], enlarged prostate [13], and colon adenomas [14, 15], some studies also reported null [16–24], and inverse [25] associations for these outcomes.