| Abstract: | BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) among Latinos is partially attributed to a prevalent C > G polymorphism in the patatin-like phospholipase 3 (PNPLA3) gene. Cross-sectional analyses in Latino children showed the association between dietary sugar and liver fat was exacerbated by GG genotype. Pediatric feeding studies show extreme sugar restriction improves liver fat, but no prior trial has examined the impact of a clinical intervention or whether effects differ by PNPLA3 genotype. OBJECTIVES: To test effects of a clinical intervention to reduce dietary sugar versus standard dietary advice on change in liver fat, and secondary-endpoints changes in liver fibrosis, liver enzymes and anthropometrics; and whether effects differ by PNPLA3 genotype (assessed retrospectively) in Latino youth with obesity (BMI ≥ 95th percentile). DESIGN: This parallel-design trial randomized participants [n = 105; 12.7% baseline liver fat, 14.8 yrs] to control or sugar reduction (goal of ≤ 10% of calories from free sugar) for 12-weeks. Intervention participants met with a dietitian monthly and received delivery of bottled water. Changes in liver fat, by magnetic resonance imaging, were assessed by intervention group through general linear models. RESULTS: Free sugar intake decreased in intervention compared to control [11.5 to 7.3% vs. 13.9 to 10.7% (% Energy) respectively, P = 0.02], but there were no significant effects on liver outcomes or anthropometrics (pall > 0.10), and no PNPLA3 interactions (pall > 0.10). In exploratory analyses, participants with whole-body fat mass reduction (-1.9 ± 2.42.4 kg), irrespective of randomization, had significant reductions in liver fat compared to participants without fat mass reduction [-2.1% (-6.5, -0.8) vs. 0.3% (-1.0, 2.2), P < 0.001]. CONCLUSIONS: In Latino youth with obesity, a dietitian-led sugar reduction intervention did not improve liver outcomes compared to control, regardless of PNPLA3 genotype. Results suggest fat mass reduction is important for liver fat reduction, confirming clinical recommendations of weight loss and a healthy diet for pediatric NAFLD. |
