TFRC and obesity due to melanocortin 4 receptor deficiency: Our previous study found that NAFLD patients of over 60 years had decreased cognitive function and increased soluble transferrin receptor (sTfR) compared with non-NAFLD people of the same age.[5] According to the Guidelines for the Diagnosis and Treatment of Dementia and Cognitive Impairment in China in 2018, metabolic factors, including blood pressure, blood lipid, blood sugar and obesity, may increase MCI risk in older people.[6] However, it is not known whether damaged cognitive function is associated with iron metabolism in older NAFLD patients.