Fatty Liver Change in Older Adults as an Important Risk Factor for Type 2 Diabetes: A Nationwide Cohort Study

Objective To examine the association between changes in fatty liver disease (FLD) over time and the risk of type 2 diabetes in elderly individuals with prediabetes. Methods A total of 156,984 elderly individuals with prediabetes who underwent national health screening in 2009 and 2011 were followed up through December 31, 2019. The FLD status was defined as a change in the fatty liver index. Prediabetes was defined as impaired fasting glucose levels at baseline. Multivariable Cox proportional hazards regression was used to calculate the hazard ratio and CIs for type 2 diabetes according to the changes in FLD. Results During a median of 8.35 years of follow-up, type 2 diabetes developed in 29,422 (18.7%) elderly individuals with prediabetes. Multivariable adjusted hazard ratio of type 2 diabetes according to FLD change was 2.22 (95% CI, 2.11 to 2.34) in individuals with persistent FLD compared with those who have never had FLD. Although overall weight loss of 5% or more was associated with a 7% lower risk of type 2 diabetes in total participants, fatty liver status was important. Even with weight loss, those with a history of fatty liver—resolved FLD, new FLD, or persistent FLD—had an increased risk of type 2 diabetes. The risk of type 2 diabetes did not increase in individuals with sustained FLD-free status, regardless of weight change. Conclusion The presence and change of FLD are important factors for the development of type 2 diabetes in elderly individuals with prediabetes.