Treatment of symptomatic osteoporosis in children: a comparison of two pamidronate dosage regimens.

Bisphosphonate treatment for bone fragility has expanded beyond children with osteogenesis imperfecta (OI) to those with other causes of low bone mass. However, clinical efficacy and optimal dosing in non-OI patients has not been established. We conducted a retrospective descriptive study of patients with non-OI-related bone fragility to describe the effects of two different pamidronate treatment regimens on the bone mineral density (BMD) and fracture rate of these children. Between 2000 and 2009, 15 non-OI patients aged 8-16 years received pamidronate 1 mg/kg intravenously for 1 day every 3 months (4 mg/kg/year) or 1 mg/kg/day for 3 days every 4 months (9 mg/kg/year). After 1 year of pamidronate, the two groups had a comparable increase in adjusted BMD and reduction in fragility fractures. No serious adverse effects were observed. Since the long-term effects of bisphosphonate are unknown, large trials are needed to delineate the minimal effective dose in these patients.

Pericardial effusion in severe hypothyroidism in children.

Pleural and pericardial effusion is a rare complication of severe hypothyroidism in children but can be present in 10 to 30% of adults. Most pediatric cases have been in children with Down syndrome. In this report, six cases of pericardial effusion in children with severe hypothyroidism with and without trisomy 21 are presented. In all patients, the pericardial effusion was managed successfully without pericardiocentesis. The effusions resolved completely in 2 to 12 months after initiation of thyroxin replacement. In conclusion, hypothyroidism should be considered in any child with unexplained pericardial or pleural effusions. Early recognition and treatment with thyroid hormone replacement could eliminate the need for unnecessary diagnostic procedures and invasive treatment measures and reduce the risk of progression to cardiac tamponade.

Congenital leptin deficiency due to homozygosity for the Delta133G mutation: report of another case and evaluation of response to four years of leptin therapy.

Congenital leptin deficiency is a rare, but treatable, cause of severe early-onset obesity. To date, two United Kingdom families of Pakistani origin carrying a frameshift/premature stop mutation, c.398delG (Delta133G), and one Turkish family carrying a missense mutation, c.313C>T (Arg(105)Trp), have been described. Affected subjects are homozygotes and manifest severe obesity and hyperphagia accompanied by metabolic, neuroendocrine, and immune dysfunction. The effects of recombinant leptin therapy have been reported in three children with the Delta133G mutation, and in all cases this has led to a dramatic resolution of clinical and biochemical abnormalities. We now report a Canadian child, of Pakistani origin but unrelated to the previously reported subjects, presenting with severe hyperphagia and obesity, who was found to be homozygous for the Delta133G mutation. In this child, 4 yr of therapy with sc injections of recombinant leptin provided additional evidence for the sustained beneficial effects of leptin replacement on fat mass, hyperinsulinemia, and hyperlipidemia. In addition, leptin administration corrected abnormal thyroid biochemistry and allowed the withdrawal of T(4) treatment, providing additional support for the role of leptin in the regulation of the human hypothalamic-pituitary-thyroid axis.