Predominant contribution of lifestyle versus metabolic risk factors to early-onset myocardial infarction (EOMI)

Background and Aims Early-onset myocardial infarction (EOMI) incidence is rising globally. While modifiable risk factors are common in young patients, the reversible nature of lifestyle factors offers a distinct preventive opportunity compared to metabolic factors. However, the relative contribution of lifestyle versus metabolic risk factors to EOMI remains inadequately quantified. This study compared the impact of composite unhealthy lifestyle versus metabolic risk factors on EOMI risk. Methods This case-control study matched 2,957 EOMI patients (aged 35-45 years) from the China Acute Myocardial Infarction (CAMI) registry with 6,562 controls from the Prospective Urban Rural Epidemiology (PURE)-China study (1:5 matching). Multivariable conditional logistic regression and population attributable fractions (PAFs) were used to evaluate and compare lifestyle (current smoking, alcohol consumption, lack of regular physical exercise) and metabolic factors (hypertension, diabetes, hyperlipidemia) with EOMI. Results The study included 2,957 EOMI cases and 6,562 matched controls. All six examined modifiable risk factors were independently associated with increased odds of EOMI. Collectively, they accounted for 61.0% (95% CI: 57.0%-65.1%) of EOMI cases. Notably, the combined PAF for lifestyle risk factors (49.0%; 95% CI: 44.8%-53.1%) substantially exceeded that of metabolic risk factors (18.8%; 95% CI: 16.5%-21.1%). Risk profiles and attributable burdens differed by sex and AMI subtype. Conclusion Modifiable risk factors—particularly lifestyle behaviors—are the predominant contributors to EOMI. They exhibit a significantly greater population-attributable risk than metabolic factors, especially among young men, highlighting a critical window for behavioral prevention.