Change of serum growth factors in infants with isolated ventricular defect undergoing surgical repair

Abstract

Background: Despite increasing clinical use and recent evidence that insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and human growth hormone (hGH) target the heart, the clinical manifestations following the change in the serum growth factors in infants with isolated ventricular septal defect (VSD) undergoing surgical repair have not been clearly defined.

Methods: Twenty normal infants (group I) and 44 consecutive infants with echocardiography established isolated VSD (aged from 3 months to 1 year; body weight from 6.0 +/- 1.8 kg to 8.2 +/- 1.6 kg) were investigated. Among 44 infants with VSD, 20 with shunt fraction, Qp/Qs < or = 1.5 were free of symptoms of congestive heart failure (group II); 24 with shunt fraction, Qp/Qs > or = 2.0 were in congestive heart failure (group IIIa); and 20 of these 24 infants had undergone VSD repair 6 months before their second study (group IIIb). Serum IGF-1, IGFBP-3, and hGH factors were determined by enzyme-linked immunosorbent assay using a monoclonal antibody.

Results: The serum levels of IGF-1, IGFBP-3, and hGH factors were 111.9 +/- 2.3 ng/mL, 22.0 +/- 2.3 ng/mL, and 3.6 +/- 0.7 microIU/mL for group I; 63.8 +/- 8.2 ng/mL, 17.1 +/- 1.6 ng/mL, and 4.1 +/- 1.2 microIU/mL for group II; 24.0 +/- 2.6 ng/mL, 9.4 +/- 0.7 ng/mL, and 14.7 +/- 3.5 microIU/mL for group IIIa; 79.4 +/- 12 ng/mL, 20.3 +/- 1.3 ng/mL, and 4.3 +/- 0.7 microIU/mL for group IIIb. In comparison to group I, the decrease in serum levels of IGF-1 and IGFBP-3 in groups II and IIIa were statistically significant (in group II 43% and 32%, p < 0.05; in group IIIa 79% and 37%, p < 0.01). Also the increase in serum level of hGH concentration in group IIIa was significant (increased threefold, p < 0.01). Interestingly, the change in serum levels of IGF-1, IGFBP-3 (decrease), and hGH (increase), returned to the normal range of serum levels after VSD repair in group IIIb. All congestive heart failure symptoms subsided in group IIIb during follow-up.

Conclusions: Improvement in serum levels of IGF-1, IGFBP-3, and hGH were identified in infants with VSD after surgical repair.