Arginine-induced insulin and growth hormone secretion in children with nutritional rickets.

We evaluated arginine-induced insulin and growth hormone (GH) secretion in ten children with vitamin D deficiency rickets and compared these values with those of eight age-matched control children. All rachitic children had biochemical (increased serum alkaline phosphatase activity and decreased calcium x phosphate product) and clinical evidence for rickets. After an intravenous infusion of arginine-HCl (10% solution, 0.5 g/kg), blood samples were obtained for the measurement of serum insulin and GH concentrations. The mean insulin level 30 min after the start of the infusion was 22.2 +/- 17.1 microU/ml for the rachitic children. This value is significantly below that for the normal children, 63.4 +/- 38.7 microU/ml (p = 0.004). Neither the fasting insulin level nor any others after the arginine infusion differed significantly from those for the control children. There were no significant differences in the fasting or the arginine-stimulated GH levels between the rachitic and control children. The concentrations of insulin-like growth factors did not differ between the two groups.