Prognostic significance of low hepatic fat content in advanced chronic liver disease: MRI-PDFF insights.

INTRODUCTION AND OBJECTIVES: The mechanisms of hepatic fat loss in late-stage metabolic dysfunction-associated fatty liver disease (MASLD) are enigmatic and the prognostic significance of low hepatic fat content (LHF) in chronic liver disease (CLD) is unknown. Proton density fat fraction (PDFF), measured by magnetic resonance imaging (MRI), is considered the most accurate noninvasive method for quantifying hepatic fat content. This study aimed to address these issues by evaluating PDFF. PATIENTS AND METHODS: This is a single-center, retrospective study involving 762 patients with CLD, measuring liver stiffness (LS) using MR elastography and PDFF using MRI. LHF was defined as a PDFF ≤ 2.7 % and hepatic reserve function was assessed using the albumin-bilirubin (ALBI) score. Multivariate analysis explored associations between variables. RESULTS: LHF was 27 % in the entire cohort, and PDFF was significantly decreased with LS ≥ 5.5 kPa (p < 0.05). On the multivariate analysis, low body mass index and ALBI score were independently associated with LHF (p < 0.05). In advanced CLD (n = 288), ALBI score and PDFF showed a significant negative correlation regardless of etiology (MASLD/non-MASLD: r= -0.613/-0.233), and the prevalence of LHF increased with progression of ALBI grade (p < 0.01 each). In addition, lower PDFF was associated with increased liver-related and all-cause mortality (p < 0.01), and Cox proportional hazards models extracted LHF as an independent prognostic factor, along with ALBI score and hepatocellular carcinoma (p < 0.05 each). CONCLUSIONS: In ACLD, hepatic reserve dysfunction contributed to hepatic fat loss independent of nutritional status, suggesting that LHF may be a poor prognostic factor in all etiologies.

Nonalcoholic fatty liver disease in Japanese patients with severe obesity who received laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) in comparison to non-Japanese patients.

BACKGROUND: The number of patients with morbid obesity is increasing worldwide. However, the prevalence of morbid obesity is still low in Japan, and therefore few systematic investigations of liver dysfunction in this population have so far been carried out. This study aimed to investigate the clinical characteristics in severe obese Japanese patients undergoing laparoscopic Roux-en-Y gastric bypass surgery (LRYGB). METHODS: Eighty-four patients with severe obesity, including 61 Japanese and 23 non-Japanese patients, were analyzed. RESULTS: The mean body mass index (BMI) was 43.7 +/- 7.8 kg/m(2), and there was no difference between Japanese and non-Japanese patients. Nonalcoholic fatty liver disease (NAFLD) was observed in 45/59 (76.2%) of the Japanese patients. Although there were no differences in the BMI and body weight, serum ALT was higher in Japanese patients in comparison to non-Japanese patients (P < 0.05). The indices for insulin resistance were significantly higher in the Japanese patients in comparison to non-Japanese patients (P < 0.01). The liver/spleen computed tomography (CT) ratios were lower in Japanese patients (P < 0.05). The laboratory data and BMI significantly improved at 1 year after LRYGB in both groups. CONCLUSIONS: Racial difference may exist difference may exist in NAFLD in patients with severe obesity. When the BMI is similar, liver dysfunction among Japanese patients with severe obesity tends to be higher than in non-Japanese patients. Japanese patients with severe obesity must therefore reduce their body weight to a greater degree in comparison to non-Japanese patients with the same BMI. LRYGB can achieve effective weight control and lower ALT levels in Japanese patients with severe obesity.