Growth hormone deficiency in autoimmune polyglandular syndrome

Growth alterations in rare forms of primary adrenal insufficiency: a neglected issue in paediatric endocrinology

Primary adrenal insufficiency (PAI) is an endocrine disorder characterized by direct adrenal failure^, with consequent glucocorticoid, and eventually mineralocorticoid, deficiency. In children, the main cause of PAI is congenital adrenal hyperplasia (CAH), due to a loss of function of adrenal steroidogenic enzymes, but also rarer forms, including autoimmune polyglandular syndrome, adrenoleucodistrophy, adrenal hypoplasia congenita, familial glucocorticoid deficiency, and Allgrove's Syndrome, may be observed. In PAI children, growth alterations represent a major issue, as both inadequate and excessive glucocorticoid replacement treatment may lead to reduced growth rate and adult height impairment. However, growth abnormalities are poorly studied in rare forms of paediatric PAI, and specific studies on growth rate in these children are currently lacking. In the present review, the currently available evidence on growth alterations in children with rare PAI forms will be summarized, with a major focus on comorbidities with a potential impact on patients' growth rate.

Autoimmune polyglandular syndrome Type 3 and growth hormone deficiency

The simultaneous occurrence of prepubertal Graves' disease, type 1 Diabetes Mellitus (DM), and Growth hormone deficiency (GHD) is uncommon. GHD has been reported in Autoimmune Polyglandular Syndrome (APS) Type 1 and Type 2 but not in APS Type 3. We report a 3-yr-old boy who presented simultaneously with type 1 DM and Graves' disease. After he developed urticarial rash to Propylthiouracil and Methimazole with persistent thyrotoxicosis, he received 8 millicuries of (131)I at 5 yr of age. We diagnosed GHD at age 8 yr 8 months because of growth deceleration (from 95 to 25%) and abnormal growth rate (3 cm/yr) despite euthyroidism, fair glycemic control, and normal weight gain. Both insulin-like growth factor (IGF) 1 (90 ng/mL; normal 113-261 ng/mL) and IGFBP3 (1.3 mcg/mL; normal 2.1-4.2 mcg/mL) levels were low and peak growth hormone level measured by RIA was 5.2 ng/mL after L-Dopa and insulin tolerance test. The rest of his pituitary functions and magnetic resonance imaging of the pituitary gland were normal. Growth hormone treatment (0.3 mg/kg/wk) was administered at 8 yr 9 months until near final adult height (FAH). Near FAH (172 cm) was close to midparental target height of 180 cm. GHD may be a component of all APS even though it is rare. Growth in treated children with Graves' disease should be followed closely as catch down growth below genetic height potential may be a harbinger of underlying GHD.

A rare case of adulthood-onset growth hormone deficiency presenting as sporadic, symptomatic hypoglycemia

Symptomatic hypoglycemia is described in children with severe GH deficiency (GHD), but is rare in adults with GHD. We describe the case of a 62- yr-old man, referred for recurrent hypoglycemic events. He reported a previous head trauma at the age of 20 yr and a diagnosis of reactive hypoglycemia at the age of 50 yr. In the last months, during a period of job-related stress, the hypoglycemic episodes became more frequent and severe (glucose <2.2 mmol/l), finally requiring hospitalization. On admission, the patient was in good general health, with normal renal and hepatic function. During hospitalization, no hypoglycemic episodes were recorded, also during a 72-h fasting test. Biochemical data and abdominal computed tomography (CT) excluded insulinoma. A tumor-induced hypoglycemia was ruled out. The 4-h oral glucose tolerance test (OGTT) showed an impaired glucose tolerance with a tendency toward asymptomatic hypoglycemia. Hormonal study disclosed low levels of GH (0.2 ng/ml) and IGF-I (51 ng/ml); the response of GH to GHRH plus arginine confirmed a severe GHD (GH peak 2.7 ng/ml). Other pituitary and counterregulation hormones were within the normal range and magnetic resonance imaging (MRI) of the pituitary gland was normal. Replacement therapy with a low dose of rhGH induced an increase of IGF-I up to low-normal values, accompanied by lasting regression of hypoglycemic events. In conclusion, hypoglycemia was the main clinical symptom of isolated adult onset GHD, in the present case. The possible pathogenesis of isolated adult onset GHD and the association of GHD with conditions predisposing to hypoglycemia are considered and discussed.