Atherogenic Index of Plasma and Atypical Lipid Indicators as a Predictor of Nonalcoholic Fatty Liver Disease in Nonobese Individuals

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a common cause of liver disease worldwide. NAFLD is commonly associated with obesity; however, a clinically significant proportion of affected individuals are nonobese. This phenotype is relatively less well studied. This study aims to evaluate the atherogenic index of plasma and other lipid-based indicators in the prediction of NAFLD in a nonobese subset of the Indian population. MATERIALS AND METHODS: This study collected data of 160 nonobese participants between the ages of 18 and 60 years from the health checkup offered at a tertiary care hospital from June 2023 to July 2023. Diagnosis and grading of NAFLD were done by ultrasound. This study examined the predictive ability of the atherogenic index of plasma (AIP) and other lipid indices by using receiver operating characteristic (ROC) curves. ROC curves were done for the prediction of the presence of NAFLD and individual grades as well. RESULTS: Predictive ability as measured by the area under the curve (AUC) of AIP for NAFLD was 0.653. Atypical lipid indicators outperformed typical indicators for the prediction of NAFLD. Lipoprotein combined index showed the highest predictive ability, followed by Castelli's index I and then AIP with AUC of 0.667, 0.660, and 0.653, respectively. Predictive ability of almost all indicators was markedly reduced for Grade 1 NAFLD. CONCLUSION: AIP and other atypical lipid indicators show limited predictive ability for NAFLD in nonobese individuals.