Association of glycated hemoglobin with non-alcoholic fatty liver disease patients and the severity of liver steatosis and fibrosis measured by transient elastography in adults without diabetes

Background Type 2 diabetes mellitus (T2DM) is a well-known independent risk factor for non-alcoholic fatty liver disease (NAFLD). However, research exploring the association between blood glucose management and the risk of NAFLD status in subjects without diabetes was insufficient. This study aimed to explore the association of glycated hemoglobin (HbA1c) with NAFLD status and the severity of liver steatosis and fibrosis in non-diabetic people. Methods A cross-sectional analysis was conducted on 2998 non-diabetic American adults using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 cycle. We used multivariable logistic regression models to evaluate the association between HbA1c and NAFLD status and the severity of liver steatosis and fibrosis. Interaction and stratified analyses were additionally performed. Results The multivariate regression analyses showed that HbA1c was associated independently with NAFLD status in all the models (model1: OR = 2.834, 95%CI: 2.321, 3.461; model 2: OR = 2.900, 95%CI: 2.312, 3.637 and model 3: OR = 1.664, 95%CI: 1.284, 2.156). We further performed the interaction and stratified analyses and discovered a significant interaction between HbA1c and BMI (P-interaction < 0.05). Finally, a robust link was shown between HbA1c level and the severity of liver steatosis, which was mainly significant in the prediabetes group, while the correlation was not significant in HbA1c level and severity of liver fibrosis after controlling for all the potential confounders. Conclusions We concluded that HbA1c level was positively correlated to the risk of developing NAFLD in a large non-diabetic American population. Moreover, HbA1c level was associated with the severity of liver steatosis in subjects with prediabetes, suggesting that routine screening for HbA1c among individuals with prediabetes is necessary.