The association of red blood cell markers with NAFLD and advanced liver fibrosis

Background: Nonalcoholic fatty liver disease (NAFLD) is an increasing disease related with metabolic syndrome (MetS). The associations between red blood cell (RBC) markers and MetS have been reported. However, whether RBC markers, including RBC count, mean corpuscular hemoglobin concentration(MCHC), and red blood cell distribution width (RDW)are associated with the risk of NAFLD and advanced liver fibrosis are still unclear. Methods: We conducted a nationally representative cross-sectional study based on National Health and Nutrition Examination Survey (NHANES) 2017-2018. NAFLD was diagnosed when controlled attenuation parameter (CAP) values ≥263 dB/m after exclusion of hepatitis B or C virus infection and significant alcohol intake. Advanced liver fibrosis was confirmed when liver stiffness measurement (LSM)≥8.6kPa. Weighted multivariable logistic regression models were performed to investigate the associations of RBC markers with NAFLD and advanced liver fibrosis. Results: 3563 participants were finally included. Of all the participants, 1818 (51%) were diagnosed as NAFLD and 288(8%) had advanced liver fibrosis. After fully adjusting potential confounders, RBC count was positively associated with NAFLD (OR=1.5, 95% CI=1.2-1.8, P<0.001) or CAP (β=12.1, 95% CI= 8.1-16.2, p <0.001) while MCHC was also positively associated with NAFLD (OR=1.2, 95% CI=1.1- 1.3, P=0.003) or CAP (β=2.7, 95% CI= 0.6-4.8, p=0.013). After fully adjusting potential confounders, RDW was positively associated with advanced liver fibrosis (OR=1.3, 95% CI=1.1-1.4, P<0.001) and LSM (β=0.2, 95% CI= 0.1-0.3, p =0.005).However, there was no significant difference in RBC count or MCHC with advanced liver fibrosis or LSM. Moreover, no significant difference was detected between RDW and NAFLD or CAP. Conclusion : We revealed that RBC count and MCHC were positively associated with NAFLD while RDW was positively associated with advanced liver fibrosis in Americans.