Low plasma levels of insulin-like growth factor 1 (IGF-1) in male patients with idiopathic osteoporosis.

Experimental studies in vitro indicate that insulin-like growth factor 1 (IGF-1) could be of importance for normal bone growth and remodelling, but the clinical relevance of these observations is unknown. In 12 consecutive young to middle-aged male patients (mean age (+/- SD) 46 +/- 8 years, range 30-57 years) with symptomatic idiopathic osteoporosis, the plasma concentrations of IGF-1 were significantly lower than in healthy subjects (0.51 +/- 0.25 vs. 0.73 +/- 0.23 U ml-1; P less than 0.01). The bone mineral densities in the spine, the femoral neck, and the forearm were significantly different between patients and control subjects. There were positive correlations between the plasma IGF-1 concentrations and the bone densities of the spine and the forearm. Three of the patients received a 5-d course of human recombinant growth hormone (GH). During this short period significant increases in plasma IGF-1 levels and in biochemical indices of bone turnover (serum bone-specific alkaline phosphatase, urinary calcium excretion) were recorded. These observations indicate that circulating IGF-1 could have an important role in maintaining bone mass, and suggest that impairment of IGF-1 production is involved in the pathogenesis of osteoporosis.     

The Familial Aplastic Crisis in Hereditary Spherocytosis. Urocanic Acid and Formiminoglutamic Acid Excretion Studies in a Case with Megaloblastic Arrest

A case of herditary spherocytosis who presented with an aregenerative crisisis reported. Evidence of megaloblastic hemopoiesis was present and was accompanied by the urinary excretion of large amounts of urocanic acid following oral dose of histidine hydrochloride. The severe illness in this patientwas accompanied by a reticulocytopenia in a younger sister who, however,remained well clinically.

Submitted on November 16, 1961 Accepted on March 8, 1962