Triglycerides Mediate Body Mass Index and Nonalcoholic Fatty Liver Disease: A Population-Based Study

Abstract

Introduction: Nonalcoholic fatty liver disease (NAFLD) is defined by the accumulation of triglycerides (TG). The body mass index (BMI) is associated with NAFLD. This large-scale cohort study was performed to evaluate and quantify the mediating effect of TG on the association between BMI and NAFLD. Methods: In total, 15,943 participants in the Kailuan Group were recruited between 2010 and 2014. The impact of TG on the association between BMI and NAFLD was determined through a mediation analysis. Results: BMI was an independent risk factor for incident NAFLD, with OR of 1.416 (95% CI 1.338–1.499) and 1.187 (95% CI 1.137–1.240) in the low-BMI and high-BMI groups, respectively (p < 0.001). The TG level was a risk factor for NAFLD in the high-BMI group, with an OR of 2.775 (95% CI 1.488–5.177; p = 0.001). Positive associations between BMI and the TG level remained in the 2 above mentioned groups after adjusting for confounders (β = 0.072 and 0.032; p < 0.001). The mediation analysis revealed that TG contributed to 26.050% of incident NAFLD in the high-BMI group (p = 0.01). Conclusion: A high BMI was an independent risk factor for incident NAFLD, and a high TG level was a risk factor in the high-BMI group (BMI ≥24). TG contributes about 25% to incident NAFLD in people with obesity.

Keywords

• nonalcoholic fatty liver disease
• body mass index
• triglycerides
• obesity