Arrhythmias & electrophysiologyCohort study

Adolescent Cardiorespiratory Fitness and the Trade-Off Between Atrial Fibrillation Risk and Cardiovascular Benefits: A Nationwide Sibling-Controlled Cohort Study

CirculationPublished

  • Cohort study with sibling control analysis
  • nationwide
  • sibling-controlled

Authors' conclusion

High adolescent cardiorespiratory fitness is associated with a small excess in AF risk during early adulthood that is outweighed by larger reductions in non-AF CVD after controlling for familial confounders.

Study context

Population
Swedish men at mandatory military conscription examinations 1972–1995 with cardiorespiratory fitness testingmen, mean age 18.3 years
Participants
1,124,049 men
Exposure
Highest vs lowest decile of adolescent cardiorespiratory fitness
Outcome
AF and non-AF CVD (eg, stroke and ischemic heart disease), composite of diagnosis or death in national registers
Follow-up
Until December 31, 2023

Main finding

As reported in the abstract

Standardised cumulative RD, highest vs lowest fitness decile, full-sibling comparison

Non-AF cardiovascular disease (CVD) RD by age 35

−0.11% (95% CI, −0.21% to −0.01%)

Atrial fibrillation (AF) RD by age 35

0.06% (95% CI, −0.01% to 0.12%)

Non-AF CVD RD by age 65

−3.91% (95% CI, −5.40% to −2.42%)

AF RD by age 65

2.30% (95% CI, 1.15% to 3.45%)

Observational data: associations, not effects.

Further findings

First events, whole cohort · median age 54.8 (AF) and 54.4 (non-AF CVD) years

First AF event
45 179 (4.0%)
First non-AF CVD event
96 404 (8.6%)

Population-wide analysis (measured confounders)

Highest vs lowest decile: small excess in AF exceeded reduction in non-AF CVD in early adulthood; reduction in non-AF CVD larger from 45 years of age onwards

Original publication

Adolescent Cardiorespiratory Fitness and the Trade-Off Between Atrial Fibrillation Risk and Cardiovascular Benefits: A Nationwide Sibling-Controlled Cohort Study. Circulation. Published 21 May 2026. doi:10.1161/circulationaha.125.078250

Summarised from the published abstract; every number is checked against it