Diagnostic significance of clinical and laboratory indices in predicting non-alcoholic fatty liver disease during screening studies

Aim. To study the significance of clinical and laboratory non-invasive indexes along with the insulin resistance index when carrying out diagnostic assessment of non-alcoholic fatty liver disease (NAFLD) during screening examinations.

Materials and methods. The study involved 348 employees working at oil-production enterprises. An ultrasound scanning of the liver was carried out to assess the criteria of NAFLD. The following indexes were calculated: fatty liver index (FLI), hepatic steatosis index (HSI), lipid accumulation products (LAP), and homeostasis model assessment of insulin resistance (HOMA1-IR). The prognostic significance of these indexes in relation to the probability of NAFLD diagnosis based on ultrasound data was studied using single-factor and multi-factor logistic regression models followed by ROC-analysis.

Results. The FLI, HSI, and HOMA1-IR indexes in single-factor logistic regression models showed a high statistical significance when carrying out diagnostic assessment the NAFLD with good model calibration capability. The percentage of correct binary classification regards the presence/absence of NAFLD amounted to 82.4% for FLI, 79.7% for HSI, and 72.7% for HOMA1-IR (p<0.001). According to the ROC-analysis, the area under the curve (AUC) by the NAFLD diagnostic assessment was 0.917 (95% CI 0.889–0.945); 0.880 (95% CI 0.846–0.915) and 0.849 (95% CI 0.764–0.934), respectively. The multi-factor logistic regression model with the inclusion of FLI and HOMA1-IR 72.7% enabled us to achieve the correct binary classification in terms of NAFLD in 84.2% of cases. When it comes to the ROC-analysis, considering the probabilities predicted in the multi-factor logistic model as the test variable and NAFLD in ultrasound examination as the state variable, it was possible to set the value of AUC 0.933 (95% CI 0.882–0.985).

Conclusion. The studied clinical and laboratory indexes (FLI, HSI, HOMA1-IR) have a high diagnostic significance regarding NAFLD diagnosed using ultrasonographic criteria. The application of the proposed two-factor logistics model makes it possible to predict the presence of NAFLD when examining a large number of patients, without involving additional ultrasound diagnostics specialists in order to use medical resources rationally.