Serum Iron:Ferritin Ratio Predicts Healthy Body Composition and Reduced Risk of Severe Fatty Liver in Young Adult Women

Abstract

Dysregulated iron metabolism is associated with altered body composition and nonalcoholic fatty liver disease (NAFLD); however, mechanisms underlying this association remain undefined. We investigated this association in 117 women. Middle-aged women (≥45 years old (y)) were heavier and had lower serum iron, higher serum hepcidin, ferritin, and severe NAFLD incidence than young adult women (<45 y). Age-adjusted linear regression analysis revealed that young adult women with the highest serum iron:ferritin ratio (Tertile 3) had a 5.08-unit increased percentage of muscle mass [β = 5.08 (1.48-8.68), p < 0.001] and a 1.21-unit decreased percentage visceral fat mass [β = -1.21 (-2.03 to -0.39), p < 0.001] compared with those with the lowest serum iron:ferritin ratio (Tertile 1; reference). The iron:ferritin dietary pattern, characterized by high consumption of beef, lamb, dairy products, fruits, and whole grains, and low consumption of refined carbohydrates (rice, noodles, and bread and pastries), and deep- and stir-fried foods, predicted a 90% [odds ratio: 0.10, 95% confidence interval: 0.02-0.47, p < 0.001] reduced risk of mild vs. moderate and severe NAFLD in young adult women. Our findings suggest that the serum iron:ferritin ratio more accurately predicts body composition and reduced risk of severe fatty liver progression in young adult women compared to middle-aged women.

Keywords: body composition; dietary pattern; non-alcoholic fatty liver disease; serum ferritin; serum iron.

Figure 1

Directed acyclic graph of reduced rank regression. ALT, alanine aminotransferase; LDL-C, low-density lipoprotein cholesterol; CML, Nε-(carboxymethyl)lysine.

Figure 2

Age-adjusted linear regression analyses of serum iron:ferritin ratio and body compositions according to the tertile group of serum iron:ferritin ratio in young adult (n = 65) and middle-aged (n = 52) women. (A) Serum iron:ferritin ratio to predict skeletal muscle mass in women <45 years; (B) Serum iron:ferritin ratio to predict visceral fat mass in women <45 years; (C) Serum iron:ferritin ratio to predict skeletal muscle mass in women ≥45 years; (D) Serum iron:ferritin ratio to predict visceral fat mass in women ≥45 years. ** p < 0.01, and *** p < 0.001 indicate statistical significance.

Figure 3

Age-adjusted odds ratio (OR) and 95% confidence interval (CI) for predicting mild vs. moderate and severe fatty liver according to the serum iron:ferritin-specific dietary pattern score determined using reduced rank regression. ** p < 0.01 indicate statistical significance.