Serum insulin-like growth factor binding protein 6 (IGFBP6) is increased in patients with type 1 diabetes and its complications

Insulin-like growth factor binding proteins (IGFBPs) are associated with insulin resistance and accelerated micro-and macro-vascular complications of diabetes. We investigated the relationship between serum levels of IGFBP6 in type-1 diabetes (T1D) patients and diabetic complications. In this study, IGFBP6 was measured in the sera from 697 T1D patients and 681 healthy controls using a Luminex assay. Mean serum levels of IGFBP6 were higher in T1D patients than controls matched for sex and age (119.7 vs 130.6 ng/ml, p < 10^-4). Subject age, sex and duration of disease have a significant impact on serum IGFBP6 levels in both T1D patients and healthy controls. Patients with complications have significantly higher mean serum IGFBP6 than patients without any complication (p = 3.5×10^-6). More importantly, conditional logistic regression analysis suggested that T1D patients are more likely to have very high levels of serum IGFBP6 (in the 4^th quartile) (OR = 1.7) than healthy controls. Furthermore, T1D patients with various complications are more likely to have very high levels of serum IGFBP6 (in the 4^th quartile) than patients without any complication (OR = 1.7-22.9). These results indicate the clinical importance of measuring IGFBP6 to the better management of T1D patients.