The Relationship between Nutritional Status and Metabolic Syndrome in Korean Adults with Impaired Liver Function: Using the 2016-2021 Korea National Health and Nutrition Examination Survey (KNHANES)

Objectives: This study aimed to investigate the associations between nutritional status, dietary behaviors, and impaired liver function with metabolic syndrome (MetS) among Korean adults. Methods: Data from 15,742 adults aged≥30 years who participated in the 2016-2021 KNHANES were analyzed. Subjects were categorized into three groups: normal liver enzyme group (NOR), elevated liver enzymes (ELE), and elevated liver enzymes with metabolic syndrome group (ELMS). Nutritional status was assessed using nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and the number of nutrients consumed below the estimated average requirement (EAR). Multinomial logistic regression analyses were conducted to evaluate the associations between impaired liver function and nutritional factors. Results: Multinomial logistic regression revealed that higher MAR was associated with a significantly lower odds of belonging to the ELMS group in men (odds ratio, OR: 0.319 and 0.309 for Model 1 and 2, respectively), Conversely, increased number of nutrients consumed below the EAR was associated with increased odds of belonging to the ELMS in both men (OR: 1.073) and women (OR: 1.060). Inadequate intakes of vitamin C, calcium, and vitamin A were particularly prominent. Conclusions: This study confirmed that impaired liver function and metabolic syndrome in Korean adults are not merely comorbid conditions but are closely associated with poor dietary quality and nutritional imbalances. Therefore, maintaining a balanced diet and implementing proactive nutritional management are essential for the prevention and management of metabolic liver diseases. These findings are expected to provide foundational data for developing effective nutritional intervention strategies.