Treatment of osteoporosis in children with glucocorticoid-treated diseases

Abstract

Glucocorticoid induced osteoporosis (GIO) is the most frequent form of drug induced osteoporosis. Glucocorticoids affect osteoblastogenesis, osteoclastogenesis and promote the apoptosis of osteoblasts and osteocytes. A decrease of bone mineral density has been described in several pediatric diseases that require glucocorticoids, both as long-term replacement therapy, such as Congenital Adrenal Hyperplasia, and as treatment of acute phase or relapses, such as asthma, juvenile rheumatoid arthritis, inflammatory bowel diseases, systemic lupus erythematosus, organ transplantation and Steroid Sensitive Nephrotic Syndrome. The increasing number of children with GIO and at risk of fractures reflects the complex nature of this condition, and the need of development of anti-osteoporotic drugs. In this review, we focus on the mechanisms of GIO in some pediatric diseases and on treatment of osteoporosis. We also report data on new signaling pathways as potential targets for future anti-osteoporotic drugs.

Keywords::

• bisphosphonates
• bone mineral density
• children
• congenital adrenal hyperplasia
• glucocorticoid
• glucocorticoid sensitive nephrotic syndrome
• osteoporosis

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Glucocorticoid-induced osteoporosis is the most frequent complication of long-term corticosteroid therapy and the most frequent cause of secondary osteoporosis.

• The International Society for Clinical Densitometry’s definition of osteoporosis in children is ‘a significant fracture such as long bone fracture of the lower extremities, vertebral compression fracture, two or more long bone fractures of the upper extremities, and a low bone mineral content (BMC) or BMD of greater than 2 standard deviations below age and sex related normal values’.

• Although many patients remain asymptomatic, fractures occur in 30–50% of glucocorticoids-treated patients, even for low doses, and during the first 6 months of treatment.

• cGC therapy is known to generate bone loss in many ways: a direct suppression of osteoblastic activity and an inhibition of digestive calcium absorption with secondary hyperparathyroidism and increased bone resorption by osteoclasts.

• Weight-bearing physical activity during childhood and puberty affects bone mass and formation. This critical period in life affects bone health during later stages and may promote or inhibit one’s tendency to develop osteopenia and osteoporosis.

• Bisphosphonates are the primary antiresorptives medications that have been used for the treatment of pediatric osteoporosis, especially intravenously administered pamidronate.