INSULIN RESISTANCE IN PRE-SCHOOL PRETERM VERY LOW BIRTH WEIGHT INFANTS

Aims To evaluate the metabolic pattern of a group of pre-school appropriate-for-gestational-age (AGA) and small-for-gestational-age (SGA) preterm very low birth weight (VLBW) infants and retrospectively verify if their growth rate in the first 2 years of life was associated with some clinical, anthropometric and laboratory characteristics. Methods Weight and length of 58 preterm VLBW infants (42 AGA\16 SGA), without major congenital anomalies, were evaluated at birth, discharge, one and 2 years of corrected age. A follow-up visit was performed at pre-scholar age (2–6 years): weight, height, waist circumference, subcutaneous skinfold thickness and blood pressure were assessed. In 34 infants a fasting blood examination was performed: glycaemia, insulin, triglycerides, high-density lipoprotein and low-density lipoprotein cholesterol, insulin resistance (HOMA-IR), were evaluated. Results Clinical characteristics were similar in AGA and SGA. 69% of SGA and 51% of AGA showed a significant weight centile crossing from birth to 2 years. Glycaemia, insulin and HOMA-IR were higher in infants with centile crossing, independently of their being AGA or SGA. Weight standard deviation scores (SDS) increment from birth to 2 years was significantly associated with pre-school body mass index SDS, waist circumference, insulin, and HOMA-IR values, also in adjusted models (confounding variables: sex, gestational age, respiratory distress syndrome at birth, being AGA or SGA, skinfold SDS, follow-up age). In a multiple regression model weight SDS was revealed as the only significant predictor of pre-school insulin (β 0.19; 95% CI 0.07 to 0.31; p = 0.006) and HOMA-IR levels (β 0.20; 95% CI 0.08 to 0.32; p = 0.004), both in AGA and SGA infants. Conclusions The adverse metabolic pattern of pre-school VLBW infants seems to be related to rapid weight growth in the first 2 years of life, independently of their being AGA or SGA.