Serum neuregulin 4 (NRG-4) level and non-alcoholic fatty liver disease (NAFLD): A case-control study.

OBJECTIVE: The current case-control study aimed to examine the association of circulating neuregulin 4 (NRG-4), a brown fat-enriched endocrine factor, with non-alcoholic fatty liver disease (NAFLD). METHODS: A total of 50 patients newly diagnosed with NAFLD with 50 age-matched and sex-matched subjects without NAFLD were recruited in the present study. Circulating NRG-4 levels were assessed with an enzyme-linked immunosorbent assay (ELISA) kit. SPSS version 23 was used for statistical analysis. RESULTS: Patients with NAFLD had lower levels of circulating NRG-4 than the control group (P < .001). Participants in the highest quartile of circulating NRG-4 had significantly lower body mass index (BMI), waist circumference (WC), triglyceride (TG) and homeostatic model assessment for insulin resistance (HOMA-IR) compared with those in the lowest quartile (all P < .01). The prevalence of NAFLD in the quartile 4 of the serum NRG-4 level was 38.46%, lower than the quartile 1 (62.50%, P = .006), quartile 2 (52.00%, P = .017) and quartile 3 (48.00%, P = .032). In multiple stepwise regression analysis, BMI (ß = -0.712, P = .016), WC (ß = -0.577, P = .023), TG (ß = -0.509, P = .001), high-density lipoprotein cholesterol (HDL-C) (ß = 0.489, P = .001) and HOMA-IR (ß = -0.609, P = .003) were independently related to serum NRG-4 level. The odds of NAFLD decreased by 41% per 1 SD increase in serum NRG-4 level (OR, 0.59; 95% CI, 0.35-0.78; P = .021), after adjustment for all potential confounders. CONCLUSION: The results of the present study demonstrate that circulating NRG-4 levels may play a protective role in NAFLD.