Objective: To examine whether lower BP mediates the inverse association between organizational justice and incident coronary heart disease (CHD). Previous studies suggest lower blood pressure (BP) and reduced risk of CHD among employees with high organizational justice (the perception of being treated fairly by supervisors).
Methods: Prospective occupational cohort study of 4250 men and 1812 women free of CHD and hypertension at study entry (the Whitehall II study). Justice was assessed at phase 1 (1985-1988) and phase 2 (1989-1990); systolic and diastolic BP at phases 1, 3 (1992-1993), and 5 (1997-1999); hypertension at phases 3 and 5; and incident CHD from phase 2 to phase 5 (231 events, mean follow-up 9.6 years).
Results: A higher level of organizational justice was associated with a slightly lower mean level of diastolic BP over time. After adjustment for age, sex, ethnicity, and employment grade, higher organizational justice was associated with lower CHD incidence. This association was not attenuated after further adjustment for measures of BP and hypertension, although these measures were associated with increased CHD risk.
Conclusions: This study suggests that sustained lower levels of BP do not represent a key mechanism through which organizational justice protects against CHD. The importance of this study is that it eliminates a strong candidate mediator of the association between organizational justice and CHD and thus allows future research to concentrate on other mechanisms.