Combined impact of prediabetes and hepatic steatosis on cardiometabolic outcomes in young adults.

Objectives: This study aimed to investigate the impact of hepatic steatosis on cardiometabolic outcomes in young adults with prediabetes.

Methods: A nationwide cohort study was conducted with 896,585 young adults under 40 years old without diabetes or previous history of cardiovascular disease. Hepatic steatosis was identified using a fatty liver index of ≥ 60. The outcomes of this study were incident diabetes (DM) and composite major adverse cardiovascular events (MACE), including myocardial infarction, stroke, or cardiovascular death.

Results: During a median follow-up of 11.8 years, 27,437 (3.1%) incident DM cases and 6,584 (0.7%) MACE cases were recorded. Young adults with prediabetes had a significantly higher risk of incident DM (hazard ratio [HR]: 2.81; 95% confidence interval [CI]: 2.74-2.88; P-value: <0.001) and composite MACE risk (HR: 1.10; 95% CI: 1.03-1.17; P-value: 0.003) compared to individuals with normoglycemia, after adjusting for relevant covariates. Stratification based on hepatic steatosis showed that the combination of prediabetes and hepatic steatosis posed the highest risk for these outcomes, after adjusting for relevant covariates. For incident DM, the HRs (95% CI; P-value) were: 3.15 (3.05-3.26; <0.001) for prediabetes without hepatic steatosis, 2.89 (2.78-3.01; <0.001) for normoglycemia with hepatic steatosis, and 6.60 (6.33-6.87; <0.001) for prediabetes with hepatic steatosis. For composite MACE, the HRs (95% CI; P-value) were 1.05 (0.97-1.13; 0.235) for prediabetes without hepatic steatosis, 1.39 (1.27-1.51; <0.001) for normoglycemia with hepatic steatosis, and 1.60 (1.44-1.78; <0.001) for prediabetes with hepatic steatosis.

Conclusions: Prediabetes and hepatic steatosis additively increased the risk of cardiometabolic outcomes in young adults. These findings hold significance for physicians as they provide insights into assessing high-risk individuals among young adults with prediabetes.