Coffee's Beneficial Effect on Liver Disease Confirmed in NASH Cohort, but Only Partially Confirmation of In Vitro Pre-Described Differentially Expressed Genes in This Patient Cohort

Abstract

Background and Aim: Recent studies have implicated several important hepatic cellular processes and signaling pathways that are affected by abnormal lipid metabolism, resulting in specific biochemical, histological, and clinical changes associated with NAFLD. We established highly sensitive and specific analysis of serum biomarkers for comprehensive view of the change in cholesterol and fatty acid metabolism by HPLC-ESI-MS/MS. By using this method, we monitored lipid metabolism in NAFLD patients before and during administration of pitavastatin. Materials and Methods: Serum samples were obtained from patients with NAFLD enrolled in multicenter case control study (n=15) at baseline, 3 months (mo), and 12 mo from initiation of pitavastatin treatment(1~2mg/day). Sex and age matched control (CTL) samples were obtained from 36 healthy volunteers with none of obesity, hyperlipidemia, and liver dysfunction. Internal standards were added to 10μL of serum. After extraction and derivatization, the samples were analyzed by LC-MS/MS equipped with reversed C18 column. Results: Markers of intestinal cholesterol absorption, serum sitosterol (CTL vs. NAFLD: 4.04±1.79 vs 1.69±0.68 ng/mL, P<0.001) and campesterol (4.77±2.13 vs. 1.71±0.79 ng/mL, P<0.001) were significantly lower in patients with NAFLD compared to CTL. Markers of LXR activity, serum 24S-hydroxy cholesterol (69.53±19.8 vs. 92.29±30.5 ng/mL, P<0.05), and 27-hydroxy cholesterol (136.0±41.94 vs. 244.7± 59.34 ng/mL) were significantly higher in patients with NAFLD compared to CTL. Lathosterol, a marker of cholesterol synthesis, tended to be higher in NAFLD but not significantly different. By pitavastatin administration, decrease of cholesterol synthesis was found during observation period. Decrease of LXR was not found at 3 mo but 12 mo follow up. Alterations in bile acid synthesis, cholesterol absorption and fatty acid synthesis were not significant over observation period of time. On the other hands, analysis of these markers in a subgroup with (responder) and a subgroup without (non-responder) decreasing ALT level revealed that decrease of bile acid synthesis (responder vs. non-responder: -22.3 vs. 69.0% of pre-treatment level) and DNL (-7.47 vs. 31.6%) were prominent in responder group, while there was no significant change in decrease of cholesterol synthesis in both group (-60.3% vs. -70.7%). Conclusions: In patients with NAFLD, intestinal absorption was inhibited by the activation of LXR. Treatment of pitavastatin lowered cholesterol synthesis and LXR activity in all patients, however, suppression of bile acid as well as DNL were observed only in patients with improved biochemical data. More research work is needed to understand the clinical meaning of these findings, which may help to understand the role of lipid lowering agents in the treatment of NAFLD.