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

Background: There 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.

Methods: We analyzed 1,097,424 participants, aged 18 to 105 years, without histories 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 to 64 years (n = 403,619); 65 to 79 years (n = 437,236); and ≥ 80 years (n = 52,734). We used 3 physical inactivity components gained from the self-reported questionnaire during a health checkup. The outcomes were composite CVD events including myocardial infarction, stroke, heart failure, and each CVD event.

Results: During a mean follow-up of 3.2 ± 1.9 years, 81,649 CVD events were observed. The hazard ratios of 3 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 to 64 years, 65 to 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.

Conclusions: The 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.