Baseline atherogenic coefficient and risk of incident chronic liver disease: a prospective cohort study from the CHARLS

Background Chronic liver disease (CLD) is a major public health burden, particularly among middle-aged and older adults. The atherogenic coefficient [(TC − HDL-C)/HDL-C]is a simple lipid-derived index widely used in metabolic risk assessment, but its longitudinal association with incident CLD remains unclear. Objective To investigate the longitudinal association between the atherogenic coefficient [(TC − HDL-C)/HDL-C]and the risk of incident chronic liver disease among middle-aged and older adults using data from the China Health and Retirement Longitudinal Study (CHARLS). Methods This prospective cohort study used data from the China Health and Retirement Longitudinal Study (CHARLS). A total of 6,721 participants aged ≥ 45 years without CLD at baseline (2011) were followed through 2020. The atherogenic coefficient was analyzed as both a continuous and categorical variable. Cox proportional hazards models were applied to assess associations with incident CLD, and restricted cubic spline models were used to explore nonlinear dose–response relationships. Results Among the 6721 participants, 552 participants (8.2%) developed chronic liver disease. Higher baseline atherogenic coefficient was associated with an increased risk of incident CLD. In fully adjusted Cox models, participants in the high atherogenic coefficient group had a significantly higher risk of CLD compared with those in the low-risk group (hazard ratio [HR] = 1.56, 95%CI-1.17-2.06; p = 0.002). Restricted cubic spline analyses suggested an overall positive association between the atherogenic coefficient and incident CLD, with the lowest estimated risk observed around an atherogenic coefficient of approximately 3 and a tendency toward higher risk at higher atherogenic coefficient levels (p for overall < 0.001). Subgroup analyses showed broadly consistent associations across examined subpopulations. Conclusions A higher baseline atherogenic coefficient may be associated with an increased risk of incident chronic liver disease among middle-aged and older Chinese adults.