Objective To investigate the relationships of triglyceride-glucose-a body shape index (TyG-ABSI) with premature coronary artery disease (PCAD) and all-cause mortality (ACM) in young adults in the United States.

Methods Data from 13 331 young participants in the National Health and Nutrition Examination Survey (NHANES) database in the United States from 2001 to 2018 were collected. Weighted logistic regression and Cox regression analyses were used to evaluate the true associations between TyG-ABSI and PCAD, and between TyG-ABSI and ACM, respectively. Restricted cubic spline (RCS) regression was employed to assess the dose-response relationships between TyG-ABSI and PCAD, and between TyG-ABSI and ACM. Receiver operating characteristic (ROC) curves were used to determine the diagnostic accuracy of TyG-ABSI for PCAD and ACM.

Results Among the 13 331 participants, 149(1.12%) had PCAD. After adjusting for multiple potential confounding factors, TyG-ABSI was significantly associated with PCAD (OR=1.83, 95%CI, 1.18 to 2.86, P= 0.008). During a median follow-up period of 115 months, 546 (3.64%) participants died. After adjusting for multiple potential confounding factors, a significant increase in ACM risk with increasing TyG-ABSI levels was observed in all participants, those without PCAD, and those with PCAD, with hazard ratios for all-cause mortality of 1.95 (95%CI, 1.60 to 2.37, P < 0.001), 1.91 (95%CI, 1.56 to 2.35, P < 0.001), and 2.05 (95%CI, 1.28 to 3.26, P=0.003), respectively. TyG-ABSI showed good discriminatory ability for the occurrence of PCAD and for ACM in all participants and those without PCAD, but poor discriminatory ability for ACM in participants with PCAD. The RCS curves revealed a "U"-shaped relationship between TyG-ABSI and PCAD and a positive linear correlation between TyG-ABSI and ACM.

Conclusion TyG-ABSI is a potential risk marker for PCAD and ACM. Monitoring and intervening in TyG-ABSI may help reduce the burden of PCAD and mortality in young adults in the United States.