Long-term follow-up of patients with elevated IGF-1 and nadir GH > 0.4 µg/L but < 1 µg/L

• Autor(a) principal: Rosario,Pedro Weslley
• Data de Publicação: 2017
• Outros Autores: Calsolari,Maria Regina
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Arquivos de Endocrinologia e Metabolismo (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2359-39972017000500426
• topic: Acromegaly; diagnosis; elevated IGF-1; GH suppression

ABSTRACT Objective To report the results of initial investigation and after 5 years of patients with a suspicious clinical scenario for acromegaly, elevated IGF-1, and nadir GH during an oral glucose tolerance test (OGTT) > 0.4 µg/L but < 1 µg/L. Subjects and methods Seventeen patients who had elevated IGF-1 (outside puberty and pregnancy) in two measurements and GH between 0.4 and 1 µg/L during OGTT were selected. Results During initial assessment, only one patient had microadenoma on magnetic resonance imaging (MRI) of the pituitary. In this patient, IGF-1 returned to normal spontaneously after 5 years. In the remaining 16 patients, spontaneous normalization of IGF-1 was observed in four and IGF-1 continued to be elevated in 12 after 5 years. None of the latter patients developed a phenotype of acromegaly, changes in physiognomy or increase in IGF-1 and no tumor was detected by imaging methods. Two patients had nadir GH < 0.4 µg/L, while the nadir GH remained between 0.4 and 1 µg/L in 10 patients. Conclusion In patients (notably young adult or adult women) without a typical phenotype in whom IGF-1 is measured due to a suspicious clinical scenario and is found to be slightly elevated, even if confirmed and in the absence of other causes, a nadir GH cut-off value of 0.4 µg/L instead of 1 µg/L in the OGTT might be inadequate for the diagnosis.