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

Abstract

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±64.67m g/dl; P=0.00], and serum insulin [6.33±2.18 vs. 15.39±12.56 μIU/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.