Supplementary Material for: Central Obesity and Liver Iron Content: A Noninvasive Assessment in General Population by Magnetic Resonance Imaging

<p><b><i>Background/Aim:</i></b> Existing evidence points to an altered status of iron metabolism in obesity. We aimed to investigate whether central obesity is independently associated with estimated liver iron content (liver T2* value) in general population that used the noninvasive assessment method by MRI. <b><i>Methods:</i></b> The study was carried out on 200 subjects randomly selected from the Golestan Cohort Study who underwent abdominal MRI. Quantitative T2* maps of entire cross-sectional area of liver were calculated using a semi-automated software for estimating the levels of iron content. Segmentation and calculation of visceral (VFA) and subcutaneous fat area (SFA) were also performed. <b><i>Results:</i></b> There was no significant difference in mean liver T2* values between obese (body mass index, BMI >30 kg/m<sup>2</sup>) and non-obese (BMI ≤30 kg/m<sup>2</sup>) subjects. After controlling for other covariates, no statistically significant association was detected between liver T2* values and VFA, SFA and VFA/SFA ratio. The drop in the relative signal intensity as an indicator of steatosis and serum ferritin predicted liver T2* values that almost had the same strength (standardized β of -0.41 and -0.41, respectively). <b><i>Conclusions:</i></b> Central obesity indices are not correlated with estimated liver iron content by MRI. Hepatic steatosis and serum ferritin seem to be the best predictors of hepatic T2* value. Since central obesity indices were not direct predictors of hepatic T2* value after the adjustment for confounding factors, it is possible that lipid accumulation in the liver locally, but not systematically, influences hepatic iron metabolism.</p>