Concomitant therapies (glucocorticoids and sex hormones) in adult patients with growth hormone deficiency.

Adult-onset GH deficiency (GHD), mostly due to organic lesions of the pituitary-hypothalamic region, is frequently associated with multiple anterior pituitary deficiencies that need long-term substitutive treatment. The GH-IGF-I axis may play an important role in modulating peripheral metabolism of hormones (adrenal, thyroid, and sex hormones) and these interactions may have clinically significant implications on the phenotypes of adult GHD patients and on the effects of the combined replacement hormonal treatment of this condition. By accelerating the peripheral metabolism of cortisol, GH therapy may precipitate adrenal insufficiency in susceptible hypopituitary patients; estrogen replacement blunts the response to GH in women whereas in men with androgen substitution the responsivity increases over time. Endocrinologists should be mindful of these phenomena when starting patients with hypopituitarism on GH replacement therapy.