Correlation between insulin resistance and liver histology in patients with nonalcoholic steatohepatitis with and without obesity

Insulin resistance (IR) plays a central role in pathogenesis of nonalcoholic steatohepatitis (NASH). The aim of this study was to correlate histopathological grading and IR in overweight/obese patients with NASH as compared with lean NASH.

Patients with NASH who underwent liver biopsy between January 2012 and December 2012 were included. Anthropometric, clinical, and biochemical features, necro-inflammatory grades, and fibrosis stage on liver biopsies were scored according to Brunt and non-alcoholic fatty liver disease (NAFLD) activity score (NAS).

Of 42 patients, 33 (78.6%) had body mass index (BMI) ≥ 23 kg/m² (overweight/obese) while 9 had BMI < 23 kg/m² (lean). Mean fasting blood sugar (FBS) and HbA1c levels in overweight/obese patients with NASH were higher than in lean NASH (p < 0.05). The median homeostatic model assessment–estimated insulin resistance (HOMA-IR) among NASH patients with BMI ≥ 23 kg/m² was higher than among those with BMI < 23 kg/m² (3.02 [0.34–17.22] vs. 2 [0.52–5.26]; p = 0.045). However, fasting insulin levels were comparable among lean and overweight/obese patients with NASH. Metabolic syndrome could be predicted with 75% sensitivity and 85.3% specificity at a HOMA-IR cutoff value of 3.9. No significant difference was observed with regard to HOMA-IR levels with Brunt grades, Brunt staging, Brunt grades 1 and 2, Brunt scores < 2 and > 2, and NAS scores, and NAS scores < 4 and > 4.

Although IR was significantly higher in overweight/obese patients with NASH as compared with that in lean patients with NASH, there was no difference in the correlation of HOMA-IR with histology between these groups.