IGFBP1 and type 2 diabetes mellitus: A borderline significant correlation between IGFBP1 DNA methylation levels and IGFBP-1 serum levels was found in non-diabetic subjects (r = 0.186, P = 0.050), but not in newly diagnosed type 2 diabetes patients (P = 0.770) or patients undergoing treatment (P = 0.230).