Simple proxies of insulin resistance identify obese metabolic dysfunction-associated fatty liver disease subjects with advanced liver disease

Abstract

Aims: Insulin resistance (IR) plays a pivotal role in the pathogenesis of Metabolic dysfunction-Associated Fatty Liver Disease (MAFLD), which can progress to liver fibrosis. We examined the relationship of different IR scores with markers of MAFLD severity in obese individuals.

Materials and methods: In this retrospective observational study, 346 non-diabetic, overweight/obese individuals with newly diagnosed MAFLD (age 50.2 ± 13.3 years, 34% females, BMI 30.8 ± 4.4 kg/m² ) underwent liver stiffness (LS) and controlled attenuation parameter (CAP) measurements by Fibroscan® to assess liver fibrosis and steatosis. Biochemical data were collected to calculate surrogate markers of IR (Homoeostasis model assessment - insulin resistance index [HOMA-IR], triglyceride-glucose index, triglyceride by HDL ratio), liver fibrosis (Nonalcoholic Fatty Liver Diseases fibrosis score, fibrosis-4 score, Aspartate aminotransferase to platelet ratio index) and steatosis (fatty liver index, hepatic steatosis index).

Results: All three IR scores were associated with CAP, while only HOMA-IR positively correlated with LS (r = 0.275, p < 0.0001), independent of age and sex, BMI, transaminases, and fibrosis markers. Insulin-resistant individuals (HOMA-IR >2.5, n = 165) had higher liver enzymes, CAP and LS, with a 4-fold increased risk of severe liver disease (LS >9.7 kPa, OR 4.42[1.95-10.01], p = 0.0002). Among HOMA-IR components, fasting plasma insulin (FPI) was independently associated with LS (r = 0.270, p < 0.0001). ROC AUC for HOMA-IR and FPI to predict severe liver disease were virtually identical (0.748 and 0.758, respectively).

Conclusions: HOMA-IR is independently associated with non-invasive markers of MAFLD severity in overweight/obese individuals. This relationship is largely mediated by hyperinsulinemia, regardless of BMI. Measuring insulin levels in MAFLD individuals might be useful to identify those at risk of liver fibrosis.

Keywords: Fibroscan; HOMA-index; MAFLD; obesity.