Clinical Management, Therapeutic Innovation, and Patient Outcomes in Growth Hormone Deficiency
Growth Hormone Deficiency (GHD) is an endocrine disorder characterized by the inadequate secretion of growth hormone ($\text{GH}$), also known as somatropin, from the anterior pituitary gland.
The pituitary is often referred to as the "master gland," and GHD can be an isolated deficiency or part of a more generalized hypopituitarism, where other pituitary hormones are also deficient. GHD can be congenital (present at birth, often due to genetic defects or structural central nervous system anomalies) or acquired (developing later in life due to brain tumors like craniopharyngioma, head trauma, radiation therapy, or infection). In many cases, particularly in children, the cause is idiopathic (unknown).
Clinical Manifestations Across the Lifespan
Childhood-Onset GHD
In children, the primary clinical manifestation is growth failure and short stature (height significantly below the fifth percentile for age and sex, with a reduced growth velocity). Unlike many other causes of short stature, children with GHD typically retain normal body proportions and may have an immature or "chubby" appearance with a prominent forehead. If left untreated, GHD leads to persistent short stature in adulthood and can be associated with delayed or absent sexual development.
Adult-Onset GHD
GHD often continues or is re-diagnosed in adulthood, particularly in individuals with a history of hypothalamic-pituitary disease. In adults, the symptoms shift from linear growth failure to metabolic and body composition changes, including:
Altered Body Composition: Increased visceral fat mass and decreased lean body mass and muscle strength.
Metabolic Derangements: Dyslipidemia (abnormal cholesterol/lipid profile) and increased insulin resistance, contributing to elevated cardiovascular risk factors.
Skeletal Health: Decreased bone mineral density, leading to an elevated risk of osteoporosis and fractures.
Psychosocial Impact: Decreased energy levels, chronic fatigue, and reduced overall quality of life and sense of well-being.