IGFBP3 and diabetes mellitus: Age (OR=1.094, 95%CI 1.038-1.153, P<0.001), FPG (OR=1.516, 95%CI 1.067-2.156, P=0.020) and IGF-1 (OR=1.040, 95%CI 1.003-1.079, P=0.033) were independent risk factors for thyroid nodules in type 2 diabetic mellitus, while IGF-1/IGFBP-3 ratio (OR<0.001, 95%CI <0.001-<0.001, P=0.020) was inversely independent protective factors for thyroid nodules in type 2 diabetic mellitus (Table 7).