Association of Non-alcoholic Fatty Liver Disease with Body Fat Percentage in Normal-Weight Individuals

Abstract

Background: Recent data have suggested that nonalcoholic fatty liver disease (NAFLD) can occur in normal-weight subjects. This study examined the association of body fat percentage (BF%) with NAFLD and its risk factors in normal-weight individuals. Objectives: The present study aimed to explain the influence of body fat on the risk of NAFLD. Methods: A total of 59 subjects with body mass index (BMI) within the range of 18.5 - 24.9 kg/m2 were selected from referrals to two major university polyclinics in Shiraz, Iran, from April to June 2019. Fatty liver grade, anthropometric characteristics, body composition, and cardiometabolic risk factors were measured in this study. Results: Waist circumference (P = 0.012), fat mass (P < 0.001), triglycerides (TG) (P = 0.027), very-low-density lipoprotein (VLDL) (P = 0.007), and TG/high-density lipoprotein cholesterol (HDL-C) ratio (P = 0.003) increased; however, skeletal muscle mass decreased (P < 0.001) across the tertiles of BF%. The average of fatty liver grade was similar in the first and second tertiles; nevertheless, the fatty liver grade of participants in the third tertile was significantly higher (1.3 ± 0.9 vs. 0.4 ± 0.7; P = 0.005). In ordinal regression analysis, BF% (1.13; 95% CI: 1.04 - 1.22; P = 0.003), BMI (1.95; 95% CI: 1.02 - 3.74; P = 0.045), VLDL (1.77; 95% CI: 1.00 - 3.12; P = 0.049), and TG/HDL-C ratio (2.21; 95% CI: 1.26 - 3.86; P = 0.006) had positive associations with NAFLD; nonetheless, HDL-C (0.33; 95% CI: 0.16 - 0.67; P = 0.002) and dietary cholesterol (0.97; 95% CI: 0.95 - 0.997; P = 0.028) had inverse associations with NAFLD after the adjustments for age, gender, BMI, and physical activity. Conclusions: The results of this study suggested that within normal weight ranges, NAFLD occurs more frequently in individuals with higher BF%. In addition, BF% can be used as an important marker in NAFLD screening.