Standing at work and progression of carotid atherosclerosis

Occupational physical activity and 20-year incidence of acute myocardial infarction: results from the Kuopio Ischemic Heart Disease Risk Factor Study

“…Higher levels of OPA were associated with a reduced risk of CVD in some prospective population-based studies (9-15) but not others (10,13,(16)(17)(18)(19)(20)(21) or were associated with an increased CVD risk (22)(23)(24)(25)(26)(27)(28) and, in one study, depending on level of fitness (29). A few studies showed differential effects, with LTPA being protective and OPA having no effect (20,30), LTPA having an effect only among persons with low levels of OPA (14), or LTPA constituting a CVD risk (23), especially among persons with high levels of OPA indicating an interaction between OPA and LTPA (28).…”

“…In addition, only three studies adjusted for psychosocial job factors (25,26,28) although job stress has been found to be an important risk factor for CVD in several studies (33)(34)(35)(36)(37) and could confound associations between OPA and CVD. Further, one cohort study found strong interactions between OPA and baseline ischemic heart disease (IHD) (25,26), however, no other cohort study investigated this possibility. Such limitations may be responsible for the inconsistent findings in the literature.…”

“…Among the few studies that used a continuous measure of energy expenditure (EE) only one adjusted for individual aerobic fitness that determines the actual cardiovascular load [relative aerobic strain (RAS) also known as relative aerobic workload] in meeting the physical demands of work in terms of the energy expended in performing the work (26). In addition, only three studies adjusted for psychosocial job factors (25,26,28) although job stress has been found to be an important risk factor for CVD in several studies (33)(34)(35)(36)(37) and could confound associations between OPA and CVD. Further, one cohort study found strong interactions between OPA and baseline ischemic heart disease (IHD) (25,26), however, no other cohort study investigated this possibility.…”

Physical activity and cardiovascular mortality – disentangling the roles of work, fitness, and leisure

“…While the beneficial effects of LTPA on the circulatory system appear well established (14,15), the evidence about the health effects of OPA remains inconsistent (16). In high quality prospective population-based studies, higher levels of OPA were associated with a reduced risk of CVD in some studies (17)(18)(19)(20)(21)(22), showed no association in others (18,21,(23)(24)(25)(26)(27)(28), or were associated with an increased CVD risk (4,(7)(8)(9)29). A few studies showed differential effects, with LTPA being protective and OPA having no effect (27), LTPA having no effect and OPA constituting a CVD risk (4), LTPA having a protective effect only among persons with low levels of OPA (22) or LTPA constituting a CVD risk (9).…”

“…The Copenhagen study is only the second study to control for fitness; unfortunately both fitness and physical demands were assessed in broad categories leading to avoidable misclassification and results that could be sensitive to the choice of cut-off points. Only two epidemiologic cohort studies adjusted for psychosocial job factors (4,29), although job stress has been found to be an important risk factor for CVD in several studies (31)(32)(33) and could confound associations between OPA and CVD. For example, in their pioneering works, Morris et al (34) attributed the lower risk of coronary heart disease among London bus conductors versus drivers to the sedentary work of the drivers.…”