Occupational Physical Activity and Fitness in Predicting Cardiovascular Mortality among European Cohorts of Middle-Aged Men: A 60-Year Follow-Up in the Seven Countries Study

Abstract

Aim and Background: To determine whether occupational physical activity (OPA) and physical fitness (Fitscore) predict cardiovascular disease (CVD) mortality and its components. Methods: Among middle-aged men (N = 5482) of seven cohorts of the Seven Countries Study (SCS), several baseline risk factors were measured, and there was a follow-up for 60 years until virtual extinction. OPA was estimated from the type of work while Fitscore was derived from linear combinations of levels of arm circumference, heart rate and vital capacity computed as a factor score by principal component analysis. The predictive adjusted power of these characteristics was obtained by Cox models for coronary heart disease (CHD), heart diseases of uncertain etiology (HDUE), stroke and CVD outcomes. Results: Single levels of the three indicators of fitness were highly related to the three levels of OPA and Fitscore. High levels of both OPA and Fitscore forced into the same models were associated with lower CVD, CHD, HDUE and stroke mortality. When assessed concomitantly in the same models, hazard ratios (high versus low) for 60-year CVD mortality were 0.88 (OPA: 95% CI: 0.78–0.99) and 0.68 (Fitscore 95% CI: 0.61–0.75), and the predictive power of Fitscore outperformed that of OPA for CHD, HDUE and stroke outcomes. Similar results were obtained in individual outcome models in the presence of risk factors. Segregating the first 30 from the second 30 years of follow-up indicated that people dying earlier had lower arm circumference and vital capacity, whereas heart rate was higher for CVD and most of its major components (all p < 0.0001). Conclusions: OPA was well related to the indicators of fitness involving muscular mass, cardio-circulatory and respiratory functions, thus adding predictive power for CVD events. The Fitscore derived from the above indicators represents another powerful long-term predictor of CHD, HDUE and stroke mortality.