Impact of body fat composition on liver iron overload severity in hemochromatosis: a retrospective MRI analysis

To evaluate the correlation between ectopic adipose tissue and iron overload severity in patients with hemochromatosis.

A retrospective cohort of 52 patients who underwent liver iron concentration quantification from January 2015 to October 2023 using a 3.0T MRI scanner. R2* relaxation times and proton density fat fraction (PDFF) were assessed for the entire liver volume and a specific region of interest (ROI) placed in the right lobe. Total body fat (TF), subcutaneous fat (SCF), intermuscular fat (IMF), and visceral fat (VSF) percentages were calculated from a single axial slice at the level of the third lumbar vertebra. Additionally, ratios of IMF-to-VSF, IMF-to-SCF, and SCF-to-VSF were calculated. Standard iron laboratory parameters were collected at least one month prior to MRI. Pearson correlation coefficient was used for correlation analysis.

The mean age of participants was 53.9 ± 19.6 years. IMF positively correlated with R2* values in the ROI (p = 0.005, r_s = 0.382) and entire liver (p = 0.016, r_s = 0.332). Conversely, VSF negatively correlated with R2* values from the ROI (p = < 0.001, r_s = - 0.488) and entire liver (p = < 0.001, r_s = - 0.459). Positive correlations were also found between IMF-to-VSF and R2* of the ROI (p = 0.003, r_s = 0.400) and whole liver (p = 0.008, r_s = 0.364). Ferritin levels positively correlated with R2* values calculated from ROI (p = 0.002, r_s = 0.417) and whole liver volume (p = 0.004, r_s = 0.397). A positive correlation was noted between PDFF of the entire liver and TF (p = 0.024, rs = 0.313).

The percentage of Intermuscular and visceral adipose tissues correlates with the severity of liver iron overload in hemochromatosis patients.