Age-Dependent Relationship of Physical Inactivity with Incident Cardiovascular Disease: Analysis of a Large Japanese Cohort

BackgroundThere have been limited studies examining age-dependent associations between physical inactivity and cardiovascular disease (CVD). We aimed to clarify the age-dependent relationship of physical inactivity with incident CVD.MethodsWe analyzed 1,097,424 participants aged 18-105 years without a history of CVD enrolled in the DeSC database (median age, 63 years; 46.4% men). We categorized participants into the following 4 groups based on age: ≤44 years (n=203,835), 45-64 years (n=403,619), 65-79 years (n=437,236), ≥80 years (n=52,734). We used three physical inactivity components gained from the self-reported questionnaire during a health checkup. The outcomes were composite CVD events including myocardial infarction, stroke, and heart failure, and each CVD event.ResultsDuring a mean follow-up of 3.2±1.9 years, 81,649 CVD events were observed. The hazard ratios of three physical inactivity components for CVD events increased with age category (P for interaction <0.001). For example, the hazard ratio (95% confidence interval) of physical inactivity defined as not doing light, sweaty exercise for 30 minutes at least twice a week for incident CVD in the groups aged ≤44 years, 45-64 years, 65-79 years, and ≥80 years were 0.97 (0.88-1.05), 1.08 (1.05-1.12), 1.12 (1.10-1.15), and 1.17 (1.12-1.21), respectively (P for interaction <0.001). This association was consistent across subtypes of CVD, including heart failure, myocardial infarction, and stroke.ConclusionsThe association of physical inactivity with a higher risk of developing CVD increased with age. Preventive efforts for physical activity optimization may be more valuable in older people.