PERCEIVED STRESS, GENDER AND OCCUPATIONAL STATUS INTERACT TO INCREASE THE RISK OF FUTURE HIGH BLOOD PRESSURE: THE IPC COHORT STUDY Short title: Current stress and future blood pressure

Contrary to lay beliefs, current perceived stress is not consistently associated with the incidence of high blood pressure (BP) in prospective studies, possibly because of moderating factors. The present prospective study examined this association and explored potential moderating effects of gender or occupational status. The 4-item Perceived Stress Scale was filled at baseline by 19,766 normotensive adults (13,652 men, mean age±standard deviation: 46.8±9.3 years), without history of cardiovascular and renal disease and not on either psychotropic or antihypertensive drugs. After a mean follow-up of 5.8±2.1 years, 3,774 participants (19.1%) had high BP, defined as having a systolic BP ≥140 mmHg or a diastolic BP ≥90 mmHg or using antihypertensive drugs. There was a significant interaction between baseline perceived stress and gender (p=0.02) in relation to high BP at follow-up. After adjustment for potential confounders, baseline perceived stress was associated with high BP at follow-up in women (OR [CI]: 1.20 [1.03-1.38]; p=0.016). In addition, the interaction between perceived stress and occupational status was significant among women (p=0.02). Baseline perceived stress was positively associated with high BP at follow-up among women of medium or low occupational status, with OR suggesting a linear increase of the risk (p=0.005). Perceived stress may be considered as a risk factor for hypertension in women of lower occupational status. Research addressing the relationships between stress and high BP should systematically look for possible interactions with gender and occupational status.