Lifestyle and metabolic risk factors in patients with early-onset myocardial infarction: a case-control study

Aims: Family history is a known risk factor for early-onset myocardial infarction (EOMI). However, the role of modifiable lifestyle and metabolic factors in EOMI risk is unclear and may differ from that of older adults.

Methods: This case-control study included myocardial infarction (MI) patients aged ≤45 years from the Bremen ST-elevation MI Registry and matched controls randomly selected from the general population (German National Cohort) at the same geographical region. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the individual and combined associations of lifestyle and metabolic factors with EOMI risk, overall and according to family history for premature MI.

Results: A total of 522 cases and 1191 controls were included. Hypertension, current smoking, elevated waist-to-hip ratio, and diabetes mellitus were strongly associated with the occurrence of EOMI. By contrast, higher frequency of alcohol consumption was associated with decreased EOMI risk. In a combined analysis of the risk factors hypertension, current smoking, body mass index ≥25.0 kg/sqm, and diabetes mellitus, participants having one (OR = 5.4, 95%CI = 2.9-10.1) and two or more risk factors (OR = 42.3, 95%CI = 22.3-80.4) had substantially higher odds of EOMI compared to those with none of these risk factors, regardless of their family history.

Conclusion: This study demonstrates a strong association of smoking and metabolic risk factors with the occurrence of EOMI. The data suggest that the risk of EOMI goes beyond family history and underlines the importance of primary prevention efforts to reduce smoking and metabolic syndrome in young persons.