Agreement Between the Prevalence of Nonalcoholic Fatty Liver Disease Determined by Transient Elastography and Fatty Liver Indices

Abstract

Nonalcoholic fatty liver disease (NAFLD) is a global public health problem linked to the rising prevalence of obesity and metabolic disorders.¹ Accurate estimates of NAFLD in populations are challenging because the gold standard for detection is liver biopsy, an invasive procedure that precludes its use in research settings.² NAFLD can also be detected via noninvasive imaging, such as ultrasound, magnetic resonance imaging-determined proton density fat fraction, magnetic resonance spectroscopy, and the controlled attenuation parameter derived via transient elastography (CAP-TE).² Given the complexities of imaging in population studies, however, many estimates have been based on calculated indices, such as the Fatty Liver Index (FLI)³ and the Hepatic Steatosis Index (HSI).⁴ Concern has been raised that the indices underestimate the prevalence of NAFLD,⁵ thus downplaying the scope of the public health challenge. Ability to examine whether these concerns are substantive has been provided by a recent study of the US population. Using data from the study, it was reported that the US prevalence of CAP-TE-determined NAFLD was 47.8%.⁶ The current analysis used data from the same national study to examine how well the fatty liver indices corresponded to CAP-TE-determined NAFLD. Because most persons with NAFLD reportedly have elevated alanine aminotransferase (ALT) levels,⁷ the correspondence between elevated ALT and CAP-TE was also examined.