Growth Hormone Deficiency in Children

Growth hormone (GH) is released in pulses from the anterior pituitary under hypothalamic control. It acts directly on tissues and stimulates production of insulin-like growth factor 1 (IGF-1), largely in the liver. IGF-1 supports growth-plate activity and linear bone growth. When GH secretion is inadequate, the child’s height velocity slows. Growth does not stop abruptly; instead, the child gradually falls away from their established percentile channel. Body proportions are usually preserved because GH deficiency affects long-bone growth relatively evenly. Weight may be relatively preserved or increase because linear growth slows more than caloric intake. A child who has always tracked near the third percentile but continues to grow at an expected rate may be healthy and constitutionally small. A child who previously tracked near the 50th percentile and progressively crosses down percentiles needs investigation, especially if weight is stable or increasing. GH deficiency may be isolated or part of broader hypopituitarism. Causes include congenital pituitary or hypothalamic abnormalities, genetic conditions, pituitary-region tumours, cranial irradiation, head trauma, neurosurgery, and infiltrative disease. Multiple pituitary hormone deficits make a structural hypothalamic-pituitary cause more...