The utility of IGF1 in the evaluation of pediatric patients with endogenous hypercortisolemia.

We report that IGF-1 levels in childhood during active hypercortisolemia and up to 1 year after resolution are on the lower side of the normal range. Our results demonstrate that IGF-1 levels during active hypercortisolemia correlate mainly with markers of Cushing syndrome. This report adds data to the current literature where reports of IGF-1 in Cushing syndrome have shown variable results. Understanding the lack of utility of IGF-1 in assessing growth parameters in the pediatric Cushing syndrome population is important for physicians caring for these patients who should not use IGF-1 for diagnostic or treatment decisions.