Distribution and associated factors of hepatic iron -- a population-based imaging study

Abstract

Context: Hepatic iron overload can cause severe organ damage. Therefore, an early diagnosis is crucial, and identification of modifiable risk factors could help to prevent manifestations of iron-driven complications. Objective: To investigate the sex-specific distribution of hepatic iron content (HIC) in a population-based sample, and to identify relevant associated factors from a panel of markers. Methods: We analysed N=353 participants from a cross-sectional, population-based cohort in Southern Germany (KORA FF4) who underwent whole-body magnetic resonance imaging. HIC was assessed by single-voxel spectroscopy with a high-speed T2-corrected multi-echo technique. A large panel of markers, including anthropometric, genetic and laboratory values as well as behavioural risk factors were assessed. Relevant factors associated with HIC were identified by variable selection based on LASSO regression with bootstrap resampling. Results: HIC in the study sample (mean age at examination was 56.0 years, 58.4% were men) was significantly lower in women (mean{+/-}SD: 39.2{+/-}4.1 s-1) than in men (41.8{+/-}4.7 s-1, p<0.001). Relevant factors associated with HIC were HbA1c and prediabetes for men, and visceral adipose tissue and age for women. Hepatic fat, alcohol consumption, and a genetic risk score for iron levels were associated with HIC in both sexes. Conclusion: There are sex-specific associations of HIC with markers of body composition, glucose metabolism and alcohol consumption.