Objectives: Small for gestational age (SGA) is associated with an increased risk of non-alcoholic fatty liver disease (NAFLD). Our aim was to investigate the correlation of birthweight with the severity of liver damage in a large cohort of children with NAFLD.
Methods: Two hundred and eighty-eight consecutive Caucasian Italian overweight/obese children with biopsy-proven NAFLD were included in the study. We examined the relative association of each histological feature of NAFLD with metabolic alterations, insulin-resistance, I148M polymorphism in the patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene, and birthweight relative to gestational age.
Results: In the whole NAFLD cohort, 12.2% of patients were SGA, 62.8% appropriate for gestational age (AGA), and 25% large for gestational age (LGA). SGA children had a higher prevalence of severe steatosis (69%) and severe portal inflammation (14%) compared with the AGA and LGA groups. Notably, severe steatosis (>66%) was decreasing from SGA to AGA and LGA, whereas the prevalence of moderate steatosis (33-66%) was similar in three groups. The prevalence of type 1 NAFLD is higher in the LGA group with respect to the other two groups (25% vs.5.2% vs.9.4%), whereas the SGA group shows a higher prevalence of overlap type (85.8%) with respect to the LGA group (51.4%) but not compared with the AGA group (75%). At multivariable regression analysis, SGA at birth increased fourfold the likelihood of severe steatosis (odds ratio (OR) 4.0, 95% confidence interval (CI) 1.43-10.9, P=0.008) and threefold the likelihood of NAFLD Activity Score (NAS)≥5 (OR 2.98, 95% CI 1.06-8.33, P=0.037) independently of homeostasis model assessment of insulin resistance and PNPLA3 genotype. The PNPLA3-CC wild-type genotype was the strongest independent predictor of the absence of significant fibrosis (OR 0.26, 95% CI 0.13-0.52, P=<0.001).
Conclusions: In children with NAFLD, the risk of severe steatosis is increased by SGA at birth, independent of and in addition to other powerful risk factors (insulin-resistance and I148M variant of the PNPLA3 gene).