早期成人期における健康的なライフスタイルの変化と中年期脂肪肝疾患リスクとの関連

While benefits of healthy behaviors are well recognized, it remains unclear whether change in healthy lifestyle in early adulthood influences steatotic liver disease (SLD) development in midlife, and to what extent genetic predisposition might modify these associations.

In the Coronary Artery Risk Development in Young Adults (CARDIA) study, we constructed a healthy lifestyle score comprised of smoking, alcohol intake, physical activity, and dietary quality in young adults aged 18-30 years at Year 0 (Y0: 1985-1986) and Y7. A score of 0 or 1 indicated an unhealthy lifestyle, while 2 to 4 indicated healthy. A 7-year healthy lifestyle change was classified as persistently unhealthy, worsened, improved, or persistently healthy. SLD at Y25 was identified by non-contrast abdominal computed tomography.

Among 2,401 participants, 545 had SLD at Y25. Compared to those who maintained a persistently unhealthy lifestyle over 7 years period (absolute risk: 28.2%, 95% CI: 24.0%-32.4%), participants with an initially unhealthy lifestyle at Y0 who subsequently improved had reduced absolute risks of SLD (17.7%, 95% CI: 13.1%-22.3%), with the multivariable adjusted relative risk (RR) of 0.64 (95% CI: 0.48-0.85). Similarly, those who with a persistently healthy lifestyle had lower SLD risk (RR: 0.79, 95% CI: 0.67-0.94). A 1-point increase in healthy lifestyle score over 7 years was associated with a 15% (95% CI: 7%-22%) reduced risk. The observed associations remained consistent, regardless of genetic risk (e.g., >median vs. ≤median of polygenic risk score, PNPLA3 rs738409 G allele carriers vs. noncarriers).

Maintaining or improving healthy behaviors during early adulthood was associated with a reduction of midlife SLD risk, regardless of genetic predisposition.