Impact of Decreased Serum Insulin-Like Growth Factor-1 Levels on Central Aortic Compliance in Small-for-Gestational-Age Infants

Background: Intrauterine growth restriction is associated with arterial hypertension in adulthood; however, the underlying mechanism is unclear. Objectives: We hypothesized that serum insulin-like growth factor-1 (IGF-1) levels affect central aortic elastic properties and structure in small-for-gestational-age (SGA) infants. Methods: Eighteen SGA infants and 22 appropriate-for-gestational-age (AGA) infants were enrolled in this study. The serum IGF-1 level within 1 h of birth and abdominal aortic echo parameters at 1 week of age were retrospectively compared. Results: In the SGA infants, IGF-1 levels (27.6 ± 17.7 vs. 42.6 ± 15 ng/ml, p = 0.006), aortic strain (10.2 ± 3.1 vs. 12.8 ± 3.1%, p = 0.01), and aortic distensibility (0.73 ± 0.19 vs. 0.92 ± 0.34 cm2/dyn × 10-4, p = 0.05) were significantly lower compared with AGA infants. By contrast, blood pressure, aortic intima-media thickness (aIMT) in relation to body weight (383 ± 163 vs. 256 ± 43 μm/kg, p < 0.001), aortic stiffness index in relation to body weight (2.0 ± 1.7 vs. 1.1 ± 0.4, p = 0.005), and arterial pressure-strain elastic modulus (293 ± 72 vs. 242 ± 78 mm Hg, p = 0.04) were higher compared with AGA infants. In the SGA infants, IGF-1 levels were significantly correlated with aortic strain (r = 0.49, p = 0.04), aIMT in relation to body weight (r = -0.61, p = 0.007), and aortic stiffness index in relation to body weight (r = -0.63, p = 0.005). Conclusions: Decreased serum IGF-1 levels in SGA infants may affect the vascular compliance and structure of the central aorta.