Abstract MP13: Association Between Visceral Adiposity Index and Non-Alcoholic Liver Fibrosis Among United States Adults With Prediabetes

Abstract

Background: Although type 2 diabetes is a well-established risk factor for non-alcoholic fatty liver disease (NAFLD) and downstream liver fibrosis, little is known about the risk factors associated with NAFLD fibrosis in adults with prediabetes. We aimed to understand whether visceral adiposity was associated with liver fibrosis, independent of insulin resistance, among participants with prediabetes. Methods: In this nationally representative, cross-sectional study, we selected non-pregnant adults ≥20 years from the National Health and Nutrition Examination Survey (NHANES) 2017-2020 with prediabetes, defined as HbA1c of 5.7-6.4%, fasting blood glucose of 100-125 mg/dl, or a self-reported diagnosis of prediabetes. We excluded those with acute transaminitis (aspartate or alanine aminotransferase >500 IU/L), excessive alcohol consumption (>1 drinks/day for females, > 2 drinks/day for males), iron overload (transferrin saturation >50%), and positive hepatitis serology. Visceral adiposity was estimated using the validated Visceral Adiposity Index (VAI) and categorized into tertiles (<1.17, 1.17-2.19, >2.19). Our primary outcome was clinically significant liver fibrosis, defined dichotomously as median Fibroscan vibration controlled transient elastography liver stiffness measurements of 7.9 kPa or greater (≥F2). We used survey design-adjusted logistic regression, adjusting for covariates determined a priori (age, sex, race/ethnicity, income, education, smoking status, physical inactivity, hypertension, hemoglobin A1c (HbA1c), total caloric intake, and Homeostatic Model Assessment for Insulin Resistance [HOMA]) to estimate odds of fibrosis. Results: Among 1,290 prediabetic adults (mean age 62y [SD, 10], 44% female, 62% non-Hispanic White, representing 37,401,474 adults across the U.S.), 121 (10%) had NAFLD fibrosis. Participants in the highest tertile of VAI were more likely to be female, older, have higher waist circumference, and have comorbid cardiac conditions. The highest tertile of VAI was associated with three times higher odds of fibrosis (highest vs. lowest tertile; OR [95% CI], 3.81 [1.65, 8.79], middle vs. lowest tertile: 4.93 [1.74, 13.34]). There was no significant multiplicative interaction between VAI and HOMA (p=0.44). The highest tertile was also associated with 170% higher odds of F1 (mild) liver fibrosis (2.70 [1.10, 6.63], middle vs. lowest tertile: 2.69 [1.26, 5.77]). Conclusion: Nearly 1 in 10 adults with prediabetes have clinically significant liver fibrosis. High visceral adiposity was associated with more than 3 times the likelihood of fibrosis, independent of insulin resistance and traditional risk factors.