Severe growth hormone deficiency and empty sella in obesity: a cross-sectional study

Obesity is associated with blunted growth hormone (GH) secretion. In some individuals, hypothalamic-pituitary (HP) structural lesions may contribute to GH deficiency (GHD). We explored pituitary morphology in obese patients with suspected GHD and its association with cardiovascular risk factors, body composition, and cardiac morphology. One hundred and eighty-four adults obese patients with symptoms and signs of GHD (147 females and 37 males; mean age 46.31 ± 12.11 years), out of 906 consecutive white obese outpatients, were evaluated. The main measures were anthropometric data, blood pressure, lipid profile, glycemic parameters, pituitary hormones, and insulin-like growth factor-1 values, echocardiography, magnetic resonance imaging (MRI) of the HP region, body composition, and growth hormone-releasing hormone plus arginine test. Seventy patients had GHD (GH peak values <4.2 μg/mL). GHD patients showed significantly higher body mass index and fat mass, lower lumbar bone mineral density, increased left ventricular mass index, and epicardial fat thickness. The MRI of the HP region showed empty sella (ES) in 69 and normal pituitary in one of the 70 GHD patients; the 114 patients with normal GH response had ES (n = 62, 54 %), normal pituitary (n = 37, 32 %), microadenomas (n = 10, 8 %), and other pituitary abnormalities (n = 5, 4 %). ES was a significant independent predictor of GH secretory capacity as determined by multiple regression analysis. The close relationship between ES and GH secretory capacity points out to the possibility of the organic nature of GHD in a portion of obese individuals and opens a new scenario with regard to the potential of GH treatment on metabolic consequences of obesity.