OCTREOTIDE ENHANCES POSITIVE CALCIUM BALANCE IN DUCHENNE MUSCULAR-DYSTROPHY

Although receptors for somatostatin are found in bone cells, the effec t of somatostatin analogs on calcium metabolism is unknown. The author s studied, in a metabolic ward, the effect of octreotide (a long-actin g somatostatin analog) and a placebo in two 6-day calcium balance peri ods in 8 children with Duchenne muscular dystrophy. As expected, octre otide (2 mu g/kg, subcutaneously, every 8 hours) reduced serum growth hormone and somatomedin (IGF-1) to levels found in growth hormone defi ciency. Octreotide enhanced calcium retention by 30% (96 mg daily [P < 0.04]) in 7 boys for whom complete data (diet, urine, and fecal calci um) were available. In 6 children with urinary calcium excretion (U-Ca ) greater than 50 mg daily, octreotide markedly lowered U-Ca, from 114 +/- 23 mg daily to 61 +/- 9 mg daily (P < 0.03). Calcium retention oc curred in patients with or without initial hypercalciuria, but the hig her the basal U-Ca, the greater was the inhibition by octreotide (r = 0.79; P < 0.03). Inactive, nonambulatory patients had a more pronounce d response of U-Ca to octreotide (P < 0.02). Octreotide caused a mild, nonsignificant reduction in fecal calcium, with no major changes in s erum calcium, phosphorus, parathyroid hormone, urinary excretion of so dium and potassium, or in creatinine clearance. Based on the current o bservations and the presence of receptors for somatostatin in bone cel ls, this hormone may have, at least on a short-term basis, an anabolic effect on calcium, perhaps favoring its deposition in bone.