Comparison of the prognostic value of a comprehensive set of predictors in identifying risk of metabolic-associated fatty liver disease among employed adults

Abstract

Objective: Metabolic-associated fatty liver disease (MAFLD) is of concern in employed adults, while the crucial indicators in predicting MAFLD are understudied in this population. We aimed to investigate and compare the prediction performance of a set of indicators for MAFLD in employed adults.

Methods: A cross-sectional study recruiting 7968 employed adults was conducted in southwest China. MAFLD was assessed by abdominal ultrasonography and physical examination. Comprehensive indicators of demographics, anthropometric, lifestyle, psychological, and biochemical indicators were collected by questionnaire or physical examination. All indicators were evaluated for importance in predicting MAFLD by random forest. A prognostic model based on multivariate regression model was constructed to obtain a prognostic index. All indicators and prognostic index were compared to evaluate their prediction performance in predicting MAFLD by the receiver operating characteristic (ROC) curve, calibration plot, and Decision curve analysis (DCA).

Results: Triglyceride Glucose-Body Mass Index (TyG-BMI), BMI, TyG, triglyceride (TG)/high-density lipoprotein-cholesterol (HDL-C), and TG ranked the top five important indicators, and TyG-BMI performed the most accurate prediction of MAFLD according to the ROC curve, calibration plot and DCA. The area under the ROC curves (AUCs) of the five indicators were all over 0.7, with TyG-BMI (cut-off value: 218.284, sensitivity: 81.7%, specificity: 78.3%) suggesting the most sensitive and specific indicator. All five indicators showed higher prediction performance and net benefit than the prognostic model.

Conclusion: This epidemiological study firstly compared a set of indicators to evaluate their prediction performance in predicting MAFLD risk among employed adults. Intervention targeting powerful predictors can be helpful to reduce the MAFLD risk among employed adults.

Keywords: Employed adults; Metabolic-associated fatty liver disease; Prediction performance; Triglyceride glucose-body mass index.

Fig. 1

Importance score of candidate predictors. Note: variable importance suggested the difference in prediction error when feature values are altered randomly to the prediction error, with a higher difference correspondence to a higher importance of the feature. Abbreviation: TyG: triglyceride and glucose index; BMI: Body Mass Index; TG: triglycerides; HDL-C: high-density lipoprotein cholesterol; ALT: serum alanine transaminase; AST: aspartate transaminase; LDL-C: low-density lipoprotein cholesterol; FPG: fasting plasma glucose; UA: uric acid; TC: total cholesterol; GLB: globulin; DBIL: direct bilirubin; TP: total protein; TBIL: total bilirubin; SII: Systemic immune-inflammation index; CREA: creatinine; IBIL: indirect bilirubin; UREA: urea; ALB: albumin

Fig. 2

Nomogram of the diagnostic model. Note: Drawing a vertical line from the axis of each predictor until it reaches the line labeled by “points”, we can calculate the point of each predictor. The summed score of points of all predictors was the total points. Drawing a vertical line in the line labeled “Total Points” from the obtained value of total points until it intercepts the line labeled “Risk”, we can obtain the risk (predicted probability) of MAFLD for a given individual. Abbreviation: MAFLD: Metabolic-associated fatty liver disease; FPG: fasting plasma glucose; CREA: creatinine; SII: Systemic immune-inflammation index; UA: uric acid. 1: living with family member, 2: living with strangers, 3: living alone, 4: living with colleagues or friends

Fig. 3

ROC curves of TyG-BMI, BMI, TyG, TyG/HDL-C, TG, and the Model for MAFLD. Note: Model: prognostic model. Abbreviation: MAFLD: Metabolic-associated fatty liver disease; TyG: triglyceride and glucose index; BMI: Body Mass Index; HDL: high-density lipoprotein cholesterol; TG: triglycerides

Fig. 4

Calibration plot of TyG-BMI, BMI, TyG, TyG/HDL-C, TG, and the Model for MAFLD. Note: The dotted line segment connecting the lower left corner to the upper right corner serves as the reference line. The solid lines in colors are plotted based on the predicted probability of MAFLD and observed probability of MAFLD. Model: prognostic model. Abbreviation: MAFLD: Metabolic-associated fatty liver disease; TyG: triglyceride and glucose index; BMI: Body Mass Index; HDL: high-density lipoprotein cholesterol; TG: triglycerides

Fig. 5

DCA curves of TyG-BMI, BMI, TyG, TyG/HDL-C, TG, and the Model for MAFLD. Note: the horizontal axis represents the risk threshold, and is the reference probability of whether an individual would develop MAFLD. The vertical axis represents the net benefit rate. “None” in the DCA suggested that all participants were non-MAFLD, “All” means that all participants were MAFLD. The lines of each index showed the clinical benefit would be obtained by using this index. Under the same threshold probability, a larger net benefit implied that the individual could obtain a higher benefit using the diagnosis. Model: prognostic model. Abbreviation: MAFLD: Metabolic-associated fatty liver disease; TyG: triglyceride and glucose index; BMI: Body Mass Index; HDL: high-density lipoprotein cholesterol; TG: triglycerides; DCA: Decision curve analysis