Age, BMI, and Type 2 Diabetes Modify the Relationship Between PNPLA3 and Advanced Fibrosis in Children and Adults With NAFLD

Abstract

Background and AimsPNPLA3 G-allele is an important determinant of disease severity in NAFLD. Here, we investigated the effect of age, BMI, and type 2 diabetes mellitus (T2DM) on the relationship between PNPLA3 G-allele and advanced fibrosis in adults and children with histologically characterized NAFLD. Methods1,047 children and 2,057 adults were included. DNA was genotyped for rs738409 in duplicate. Primary outcome of interest was advanced fibrosis (fibrosis stage ≥ 3). Regression analyses were performed after controlling for relevant co-variates. An additive model was used to assess the effect of PNPLA3 G allele (CC vs CG vs GG). ResultsPNPLA3 G-allele was significantly associated with advanced fibrosis in both children (OR:1.55, 95% CI: 1.16-2.09) and adults (OR:1.55, 05% CI: 1.16-1.54). Across the cohort, older age significantly increased the risk for advanced fibrosis for PNPLA3 CC (OR: 1.019, 95% CI: 1.013-1.026), CG (OR: 1.024, 95% CI: 1.018-1.030), and GG (OR: 1.03, 95% CI: 1.023-1.037) genotypes. BMI significantly increased the relationship between PNPLA3 genotypes and advanced fibrosis in both children and adults. A BMI of 30kg/m2 was the cut-off beyond which PNPLA3 G-allele had exponential effect on the risk for advanced fibrosis in both children and adults. T2DM significantly worsened the relationship between PNPLA3 G-allele and advanced fibrosis in both children and adults (interaction P<0.01 for both). ConclusionAge, BMI, and T2DM modify the risk of advanced fibrosis associated with PNPLA3 G-allele. Preventing or reversing T2DM and obesity in persons carrying PNPLA3 G-allele may lower the risk for advanced fibrosis in NAFLD.