Serum proteomic analysis revealed diagnostic value of hemoglobin for nonalcoholic fatty liver disease.

BACKGROUND & AIMS Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. The two linked studies presented herein aimed to identify and verify new biomarkers for NAFLD. METHODS First, 70 serum samples were analyzed using proteomics approaches to identify potential biomarkers for NAFLD. Second, a total of 6944 initial NAFLD-free subjects were followed up for 3 years to evaluate the predictive value of hemoglobin for NAFLD. RESULTS In the first study, 20 differentially expressed protein peaks (11 up-regulated and nine down-regulated) were observed in NAFLD patients upon comparison to the controls. With the aid of bioinformatic tools, we established a biomarker pattern for NAFLD with a sensitivity of 89% and a specificity of 83%. Further analysis suggested a protein peak to be hemoglobin subunit alpha. In the second study, prospective analysis showed that subjects with higher baseline hemoglobin levels were associated with higher incidence of NAFLD. Cox proportional hazards regression analyses showed that the age, gender, and body mass index adjusted hazard ratio (95% CI) for subjects with baseline hemoglobin level in quintile 2, 3, 4, and 5 vs. quintile 1 was 1.36 (1.02-1.81), 1.66 (1.23-2.25), 1.76 (1.28-2.41), and 1.83 (1.33-2.53), respectively. CONCLUSIONS Our study showed that serum hemoglobin may have significant predictive value for NAFLD.