Unveiling NOSTRIN as a potential diagnostic marker of vascular impairment in MASLD.

Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) complications are an expanding health problem concomitant with endothelial dysfunction (ED) at early stages of the disease. This study aimed to identify the levels of a novel endothelial nitric oxide synthase (eNOS) trafficking inducer, Nostrin, in patients with MASLD compared to healthy volunteers (HV). Additionally, we investigated the association between Nostrin and endothelial dysfunction (ED) in MASLD patients.

Materials and methods: This cross-sectional analytical study included 40 MASLD patients and 40 HV as controls. Established ED biomarkers, such as asymmetric dimethylarginine (ADMA) and cyclic guanosine monophosphate (cGMP), the oxidative stress marker 4-hydroxynonenal (HNE) and Nostrin, were measured using commercially available ELISA kits. Flow-mediated dilation (FMD) of the brachial artery was assessed non-invasively using ultrasonography (USG) to measure endothelial function.

Results: Compared to HV, MASLD patients exhibited elevated serum levels of Nostrin (p < 0.0001). Similarly, serum levels of ADMA and cGMP were significantly higher in MASLD patients than in HV (p < 0.0001). Furthermore, FMD of the brachial artery was significantly reduced in MASLD patients compared to HV (p < 0.0001). Elevated NOSTRIN levels were positively correlated with lipid profiles and markers of ED, and negatively correlated with FMD. Notably, area under the curve (AUC) suggest that Nostrin demonstrates a strong performance in differentiating MASLD patients from healthy controls patients.

Conclusion: These findings suggest that Nostrin may contribute to the vascular impairment observed in MASLD and thus, it holds potential as a novel biomarker for identifying and managing endothelial dysfunction in patients with MASLD.