UCLA

High blood pressure is one of the most ubiquitous medical conditions in the world, and is a major risk factor for cardiovascular morbidity and mortality worldwide. While several risk factors have been described for high blood pressure, work stress particularly among working females, is still being investigated. This dissertation (1) examined the role of work stress for elevated ambulatory blood pressure (ABP) levels among female hotel room cleaners, (2) investigated potential modifying factors of work stress like social support and medication use, and (3) estimated potential bias introduced when using different methods of blood pressure measurement.

The first study investigated the associations between job strain and ABP and pulse pressure (PP) among female hotel room cleaners by time of day, and the modifying effects of social support at home and at work. We found that higher job strain was associated with increased systolic 18-hr ABP, after work hours systolic ABP, and ambulatory PP. Dependents at home but not social support at work attenuated effects. We also found that among workers with hypertension, anti-hypertensive medication may have mitigated ABP effects of job strain during work hours.

The second study investigated the associations between effort-reward imbalance (ERI) and ABP and PP among female hotel room cleaners by time of day, and the modifying effects of age and the number of dependents at home. We found that ERI was positively associated with ABP, particularly systolic ABP, and the association was modified by age and the number of dependents at home, although the estimates were imprecise.

The third study was designed to suggest an approximation of the effects of job stress, including job strain and ERI, on ABP using measurements of resting blood pressure (RBP) for use in studies of the impact of work stress on blood pressure. We found that estimates using RBP underestimated associations between work stress and systolic blood pressure when compared with ABP, but were less consistent when evaluating associations with diastolic blood pressure.

The findings from this dissertation help strengthen the conclusion that work stress increases blood pressure, particularly systolic blood pressure, in this understudied population of mostly immigrant, female workers. It also suggests that job stress studies using RBP underestimate the risk of elevated ABP levels.