Low hair copper concentration is related to a high risk of nonalcoholic fatty liver disease in adults.

Copper, an essential micronutrient, is required for lipid metabolism, mitochondrial function, iron metabolism, and antioxidant defense. Copper deficiency has been linked to alterations in lipid metabolism and various metabolic processes of the liver, including nonalcoholic fatty liver disease (NAFLD); however, most of these studies relied on copper measurements in the blood or tissues. In this study, we investigated the association between hair copper concentration and NAFLD in Korean adults, independent of metabolic syndrome status. Clinical and laboratory parameters, including factors of metabolic syndrome, were analyzed in 751 Korean adults divided into quintiles, according to hair copper concentration. Lower hair copper concentration was significantly correlated with higher body mass index, waist circumference, blood pressure, and lower levels of high-density lipoprotein cholesterol. Subjects with NAFLD showed significantly lower hair copper concentrations, and the risk of NAFLD was significantly higher for the lower hair copper quintile groups even after adjusting for metabolic syndrome-related factors. Overall, this study suggests that lower hair copper concentration could be associated with NAFLD, independent of metabolic syndrome factors.