“…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).…”