Nonalcoholic fatty liver disease (NAFLD) without insulin resistance: Is it different?

Background and aims: Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of insulin resistance [IR]. However, a significant proportion of NAFLD patients are devoid of IR. Is NAFLD sans IR a different entity? The aim of the study was to compare the anthropometric, metabolic, biochemical, ultrasonography, and histological profile of NAFLD patients with and without IR. Methods: Retrospective analyses of 336 NAFLD patients diagnosed during the last two years was done. Patients without IR were compared with those with IR. Results: Out of 336 patients, 153 [45.53%] were without IR. Although age, gender, BMI and transaminase levels were comparable, significantly higher proportion of patients in non-IR group were non-obese [43.14% vs. 25/14%; P = 0.0005], and had mild fatty change on ultrasonography; [78.43% vs. 67.21%; P = 0.022]. Higher proportion of them had elevated transaminases; [67.97% vs. 56.83%; P = 0.036]. Serum triglyceride [178.52 +/- 78.78 vs. 204.86 +/- 94.72 mg/dl; P = 0.02], FBG [85.39 +/- 13.80 vs. 98.93 +/- 31.56 mg/dl; P = 0.00], PGBG [123.76 +/- 36.77 vs. 148.07 +/- 64.67 mg/dl; P = 0.00], and serum insulin [6.33 +/- 2.18 vs. 15.39 +/- 12.56 +/- IU/ml; P = 0.00] were significantly lower in patients without IR. Although there was no difference in histology, interestingly fibrosis was seen in one third of patients despite absence of IR. Conclusion: Nearly half of our NAFLD population was without IR; one third of them had significant fibrosis. NAFLD is probably a heterogeneous disease and IR is not the sole factor responsible for NAFLD; further studies are needed to find out other possible etiological factors. (C) 2014 Elsevier Masson SAS. All rights reserved.