Unraveling the Lack of Correlation between RBP4 and MASLD: Insights from Gene Expression and Serum Level Analysis

Abstract

Although previous evidence supports the involvement of retinol binding protein 4 (RBP4) in metabolic dysfunction-associated steatotic liver disease (MASLD), there are conflicting reports. Our aim was to evaluate the role of RBP4 in MASLD among a homogeneous cohort of women with morbid obesity (MO). We recruited 180 women with MO, including 40 with normal liver (NL), 40 with simple steatosis (SS), and 100 with metabolic dysfunction-associated steatohepatitis (MASH). Serum levels of RBP4 were analyzed by an enzyme-linked immunosorbent assay. RBP4 hepatic mRNA expression was evaluated by a quantitative polymerase chain reaction. In this sense, we did not report significant differences in RBP4 circulating levels between hepatic histological groups. However, analyzing RBP4 hepatic mRNA expression, we observed decreased expression of RBP4 in MASH subjects compared to those with NL or SS. To conclude, in a homogeneous and sizeable cohort of women with MO and MASLD, our findings limit, contrary to previous proposals, the key role of RBP4 in relation to MASLD and MASH pathogenesis. Therefore, new studies are necessary in other study groups to validate the absence of this correlation.