Correlation between noninvasive methods and liver pathology in patients with non-alcoholic fatty liver disease combined with type 2 diabetes mellitus

Objective To evaluate the accuracy of different noninvasive methods for the diagnosis of nonalcoholic steatohepatitis(NASH) and hepatic fibrosis in patients with non-alcoholic fatty liver disease (NAFLD) combined with type 2 diabetes mellitus(T2DM). Method A prospective comparative study was performed for 91 patients with T2DM and NAFLD, which were diagnosed by glucose tolerance test and liver biopsy. The height and body mass of the patient were measured, and the body mass index(BMI) was calculated. The fasting venous blood of the patient was collected, and then the blood routine, liver function and ferritin were measured. NPS, neutrophil lymphocyte ratio(NLR), BARD score, FIB-4 index, APRI, and NAFLD fibrosis score(NFS) were calculated. All patients underwent transient elastography (Fibrotouch) to evaluate the degree of liver stiffness measurement (LSM) and controlled attenuation parameter. All the liver biopsy specimens were categorized by SAF as the gold standard for evaluating NASH and liver fibrosis NASH. Correlation analysis was applied to compare the correlation between the noninvasive methods and SAF. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to assess the diagnostic value of the noninvasive methods for NASH and liver fibrosis NASH. Results In T2DM combine with NAFLD patients, NPS, LSM, NFS, APRI, FIB4 and BMI scores were positively correlated with SAF(r value was 0.509, 0.508, 0.252, 0.396, 0.313 and 0.213, respectively; P value was <0.001, <0.001, 0.016, <0.001, 0.003 and 0.043, respectively). LSM, NPS, NFS and FIB4 scores were positively correlated with liver fibrosis (r value was 0.535, 0.337, 0.315 and 0.315, respectively; P value was <0.001, 0.001, 0.002, 0.002, respectively). The ROC curve shows that the area under the curve of NPS, LSM, APRI, FIB4 and BMI for diagnosing NASH was 0.838, 0.760, 0.734, 0.623 and 0.682, respectively, and P value was 0.000, 0.000, 0.000, 0.044 and 0.003, respectively. For the diagnosis of fibrotic NASH, that value of LSM, NFS, FIB4 and NPS was 0.795, 0.765, 0.686 and 0.623, respectively, and P value was 0.000, 0.001, 0.020 and 0.123, respectively. Conclusions NPS, LSM and APRI have good clinical diagnostic value for NASH. LSM and NFS have good diagnostic value for fibrotic NASH. Key words: Type 2 diabetes; Non-alcoholic fatty liver disease; Nonalcoholic steatohepatitis; Hepatic fibrosis; Liver stiffness; Noninvasive predictors