Advances in the recognition and treatment of endocrine complications in children with chronic illness.

Children with chronic illness live with the specific consequences of their illness, as well as secondary endocrine abnormalities that further compromise growth and pubertal development. These secondary abnormalities may significantly add to their physiologic and psychological burden. Although these endocrine abnormalities theoretically arise as adaptations to the chronic illness, they may have deleterious effects if they persist untreated. Children with HIV infection and other wasting disorders, for example, show growth suppression out of proportion to the severity of their primary illness as a result of growth hormone resistance and enhanced cortisol secretion. In hematologic conditions such as sickle cell anemia, thalassemia, or bone marrow transplant, damage to the hypothalamus and/or pituitary may lead to growth hormone deficiency, gonadal insufficiency, and hypothyroidism. Growth and pubertal delay are also common among children with cystic fibrosis, along with insulin-dependent diabetes mellitus caused by pancreatic fibrosis. Similarly, children receiving long-term steroid therapy have delays in growth and pubertal development, accompanied by risk for osteoporosis, whereas chronic renal disease is associated with growth and pubertal delay, as well as secondary hyperparathyroidism. Recognition of potential endocrinopathies in children with chronic illness is an important aspect of the care of these children because the disturbances are frequently amenable to treatment, permitting full or partial restoration of normal growth and development in these children. In this chapter, the endocrine consequences of common chronic conditions of childhood are reviewed, as well as the etiology of the endocrine disturbance, the clinical consequences, and recommendations for treatment.