Dị hình giới tính trong bệnh gan nhiễm mỡ liên quan đến rối loạn chức năng chuyển hóa (MASLD): Phân tích tương tác và phi tuyến về mối liên quan giữa TyG-BMI và FIB-4

Abstract

While Triglyceride-Glucose Body Mass Index (TyG-BMI) is a robust marker for insulin resistance in metabolic dysfunction-associated steatotic liver disease (MASLD), its sex-specific relationship with the Fibrosis-4 (FIB-4) index remains unclear. This cross-sectional study analyzed 222 adult MASLD patients (104 males, 118 females) using multivariable linear regression with an interaction term (TyG-BMI × Sex) and Restricted Cubic Splines (RCS) to assess non-linear trajectories between TyG-BMI and log-transformed FIB-4, adjusting for clinical confounders. Sex-stratified models revealed profound sexual dimorphism. In females, TyG-BMI demonstrated a paradoxical, significant negative association with FIB-4 (β = -0.0033, p = 0.007). Conversely, no significant association existed in males (p = 0.590). RCS analysis confirmed a declining FIB-4 trajectory at higher TyG-BMI percentiles in females, whereas the male trajectory remained flat. Conclusively, the TyG-BMI and FIB-4 relationship is strongly modulated by sex in MASLD. The paradoxical negative correlation in females highlights estrogen's potential protective role against fibrogenesis and the mathematical limitations of FIB-4 in younger, obese populations, necessitating sex-aware clinical approaches.