To assess independent predictors of FLI, a multivariate regression model using backward stepwise removal was used, entering FLI as a dependent variable and age, sex, diagnosis (CD vs. NFPA), untreated hypogonadism (primary + secondary), adrenal insufficiency, average daily intake of hydrocortisone replacement, untreated GHD, IGF-1 and hypothyroidism. This evidence concerns the gene IGF1 and non-functioning pituitary adenoma.