Body weight variability and the risk of incident metabolic dysfunction–associated steatotic liver disease (MASLD): a retrospective cohort study from the Kangbuk Samsung Health Study

Fatty liver is associated with an increased risk of type 2 diabetes, but whether an increased risk remains in people in whom fatty liver resolves over time is not known. The objective of the study was to assess the risk of incident diabetes at a 5-year follow-up in people in whom: 1) new fatty liver developed; 2) existing fatty liver resolved, and 3) fatty liver severity worsened over 5 years. A total of 13 218 people without diabetes at baseline from a Korean occupational cohort were examined at baseline and after 5 years, using a retrospective study design. Fatty liver status was assessed at baseline and follow-up as absent, mild, or moderate/severe using standard ultrasound criteria. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for incident diabetes at follow-up were estimated after controlling for multiple potential confounders. Two hundred thirty-four people developed incident diabetes. Over 5 years, fatty liver resolved in 828, developed in 1640, and progressed from mild to moderate/severe in 324 people. Resolution of fatty liver was not associated with a risk of incident diabetes [aOR 0.95 (95% CIs 0.46, 1.96), P = .89]. Development of new fatty liver was associated with incident diabetes [aOR 2.49 (95% CI 1.49, 4.14), P < .001]. In individuals in whom severity of fatty liver worsened over 5 years (from mild to moderate/severe), there was a marked increase in the risk of incident diabetes [aOR 6.13 (2.56, 95% CI 14.68) P < .001 (compared with the risk in people with resolution of fatty liver)]. Change in fatty liver status over time is associated with markedly variable risks of incident diabetes.