An unstable work environment, where workers are unsure of their roles and lack clear communication, increases the risk of heart attack, according to a large longitudinal study published in The American Journal of Public Health (2008; 98, doi:10.2105/AJPH.2007.122382.). Finnish researchers from the Finnish Institute of Occupational Health in Helsinki studied 7,663 employees for 18 years. None of the workers had a history of heart disease when the study began.
The scientists reached their conclusion by measuring predictability at work—specifically, clarity of goals; ability to foresee work problems and changes (i.e., a low incidence of unexpected changes); and work awareness, or knowledge of how one’s tasks related to the whole. After adjusting for other factors, investigators found that low predictability at work was associated over time with a higher risk of heart attack.
The scientists did not identify the mechanisms underlying this result. However, they suggested that, among other factors, an increase in sympathetic nervous system activity might have led to cardiac instability or mental strain, which in turn could have elevated the risk of hypertension and metabolic syndrome.