Factors Associated with Nonalcoholic Fatty Liver Disease in a Non-Overweight/Obese and Overweight/Obese Chinese Population at Risk for Metabolic Syndrome: A Cross-Sectional Multicenter Study

<b><i>Background:</i></b> To investigate the association of demographic, clinical, and metabolic factors with nonalcoholic fatty liver disease (NAFLD) in a non-overweight/obese and overweight/obese Chinese population at risk for metabolic syndrome. <b><i>Patients and Method:</i></b> A cross-sectional multicenter study was conducted using convenience sampling from eight selected counties/cities in Zhejiang, China, between May 2021 and September 2022. Demographics, epidemiological, anthropometric, and clinical characteristics were obtained from a questionnaire. Least absolute shrinkage and selection operator (LASSO)-logistic regression analysis was used to identify the variables associated with NAFLD. Receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were performed to evaluate the diagnostic value and clinical utility of the variables and models. <b><i>Results:</i></b> A total of 1739 patients were enrolled in the final analysis, 345 (19.8%) were non-overweight/obese and 1394 (80.2%) were overweight/obese participants. There were 114 (33.0%) and 1094 (78.5%) patients who met the criteria for NAFLD in the non-overweight/obese participants and the overweight/obese participants respectively. Older age, current smoking, higher triglyceride (TG) levels, higher AST levels, higher albumin levels, lower insulin levels, and higher controlled attenuation parameter (CAP) scores were associated with NAFLD in both non-overweight/obese and overweight/obese participants. The combination of TG+CAP scores had strong predictive values for NAFLD, especially in non-overweight/obese (Area Under Curve = 0.812, 95% confidence interval: 0.764-0.863). DCA showed a superior net benefit of the TG+CAP score over other variables or models, suggesting a better clinical utility in identifying NAFLD. <b><i>Conclusions:</i></b> More stringent lipid management strategies remain essential, and the convenience and efficacy of transient elastography for liver steatosis should be recognized, especially in the non-overweight/obese population.