Effect on atrial natriuretic peptide by bracing in scoliosis. Boston brace removal studied in 10 cases

The immediate effect of Boston brace removal on plasma levels of atrial natriuretic peptide and arginine vasopressin was studied in 10 patients with idiopathic scoliosis ranging in age from 12 to 16 years. Blood samples were drawn via the antecubital vein in the supine position with the brace on and 10 min after brace removal. ANP and AVP plasma levels were measured by radioimmunoassay. Although no differences were found in the plasma concentrations of arginine vasopressin while on and after removal of the brace, atrial natriuretic peptide levels showed an approximately 80 percent increase 10 min after brace removal, presumably due to central volume redistribution. The changes of atrial natriuretic peptide plasma levels observed may be related to previously reported changes of the glomerular filtration rate and urinary sodium excretion following brace removal.