MRI-derived hepatic fat and its clinical correlates in non-transfusion-dependent thalassemia: a cross-sectional study

We quantified hepatic fat fraction (FF) by magnetic resonance imaging (MRI) in non-transfusion-dependent thalassemia (NTDT) patients, and we evaluated its associations with demographic, clinical, and biochemical parameters, tissue iron overload, and alterations of glucose metabolism. 169 NTDT patients (45.75 ± 13.41 years, 56.8% females) enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network underwent standardized MRI assessments of hepatic, pancreatic, and cardiac iron and of hepatic FF. We also considered 301 transfusion-dependent thalassemia (TDT) patients and 25 healthy controls. To ensure reliable FF quantification, patients with severe hepatic iron overload (R2* > 333 Hz) were excluded. Glucose metabolism was assessed using an oral glucose tolerance test (OGTT). Both regularly transfused (RT) and never/sporadically transfused (NT) NTDT patients had hepatic FF values comparable to those of healthy controls, but significantly lower than those observed in TDT patients. RT-NTDT patients exhibited lower hepatic FF and hepatic iron levels than NT-NTDT patients. Independent of transfusional status, hepatic FF was unrelated to age, sex, splenectomy, ferritin, hepatitis C infection, or pancreatic and cardiac iron. In NT-NTDT, hepatic FF correlated positively with liver iron concentration. In RT-NTDT, hepatic FF and pancreatic iron showed similar diagnostic performance in identifying abnormal OGTT results. NT-NTDT patients exhibited higher hepatic FF than RT-NTDT patients, linked to hepatic iron levels. Hepatic fat accumulation and pancreatic iron overload may jointly contribute to altered glucose metabolism in RT-NTDT.