What is the Origin of Isolated Growth Hormone Deficiency?

The term "isolated" emphasizes that the hormonal deficit is confined solely to Growth Hormone, highlighting the specific nature of the pituitary dysfunction. The recognition of Adult Growth Hormone Deficiency (AGHD) as a clinically relevant syndrome, even after skeletal maturity, led to a deeper understanding of GH's essential role in metabolism and body composition. Diagnosis relies on specific provocative tests to assess the pituitary's GH secretory capacity.

What is the Mechanism of Isolated Growth Hormone Deficiency?

The underlying mechanism involves a defect in the somatotropic axis, often stemming from a genetic mutation affecting the GH gene or the hypothalamic Growth Hormone-Releasing Hormone (GHRH) signaling pathway. This disruption prevents the normal, pulsatile release of GH from the pituitary somatotroph cells. The resulting low levels of GH and secondary low Insulin-like Growth Factor 1 (IGF-1) impair anabolic processes, leading to the characteristic metabolic and body composition abnormalities of the syndrome.

Isolated Growth Hormone Deficiency

Meaning

Isolated Growth Hormone Deficiency (IGHD) is a specific endocrine disorder characterized by the inadequate secretion of Growth Hormone (GH) from the anterior pituitary gland, occurring without any concurrent deficiency in the secretion of other pituitary hormones. This clinical diagnosis is distinct from panhypopituitarism, which involves multiple hormone deficits. IGHD can present in childhood with short stature or in adulthood, manifesting as altered body composition, reduced bone density, and impaired psychological well-being.