Physical activity in youth and cardiovascular disease risk in later-life: Mediation by mid-life factors in a large cohort of Swedish adults

Objective

The aims were to investigate the association between youth physical activity and the risk of cardiovascular disease (CVD) later in life in men and women and whether mid-life lifestyle-associated factors, including exercise, smoking, Body Mass Index (BMI), and cardiorespiratory fitness (VO₂max), mediate this association.

Methods

Data from 269,431 Swedish participants (52 % men) who participated in occupational health profile assessments between 1995 and 2023 were included. Youth physical activity was self-reported as overall participation in school-based physical education and physical activity outside school before age 20. CVD incidence was obtained from national registers. Mediation analyses assessed mid-life lifestyle-associated factors' influence on the association.

Results

Compared to those reporting no physical education participation, participation in only physical education was associated with a 18 % lower risk for CVD later in life (HR = 0.82, 95 % CI 0.70,0.95). Participating in additional physical activity outside school yielded varying risk estimates (HR = 0.78, 95 % CI 0.67,0.90 for one to two times/week; HR = 0.84, 95 % CI 0.73,0.97 for three to five times/week). VO₂max, BMI, and smoking mediated 16 %–32 % of the association. In the single mediation model, cardiorespiratory fitness explicitly mediated the association in those who participated in physical education and at least one weekly sessions of physical activity outside school.

Conclusion

Youth refraining from participating in physical education class could be considered a risk group for later-life CVD. Mediation analyses suggest that engaging in only physical education or with additional physical activity outside school in youth, may confer more healthy behaviour in mid-life, which explain the lower CVD risk.