Environmental influences on blood pressure and the role of job strain.

OBJECTIVE: To review the evidence that human essential hypertension is at least in part the result of the influence of psychosocial factors, with special reference to occupational stress (job strain). FINDINGS: The prevalence of human hypertension is related to social factors such as urbanization and education. Several studies, conducted both experimentally in animals and observationally in people, have suggested that chronic social conflict is associated with higher blood pressure. Ambulatory monitoring has shown that most people have their highest pressures during working hours. Occupational stress can be evaluated as job strain, which is a combination of high demands at work with low decision latitude or control. Job strain has been related to coronary heart disease, and a number of studies have shown that it is also associated with higher ambulatory blood pressures, both cross-sectionally and prospectively, in men but not in women. Men in high strain jobs also show an increased left ventricular mass. Laboratory studies of blood pressure reactivity to stressful tasks support the concept of loss of control being associated with higher pressures. CONCLUSIONS: Job strain is a risk factor for hypertension in men, but not in women.