People who work more than 40 hours per week in white-collar jobs are more likely to have high blood pressure than those working 40 or fewer hours, according to new research in the American Heart Association journal Hypertension.
For the study, more than 3,500 Canadian insurance industry workers had their clinic blood pressure (CBP) and ambulatory blood pressure (ABP) checked at three time points during five years. The workers also reported weekly working hours: 21 to 34; 35 to 40; 41 to 48; or 49 or more.
Those who reported working 41 to 48 hours or 49 or more hours per week had a higher prevalence of both masked hypertension (CBP <140/90 mmHg and ABP ≥135/85 mmHg) and sustained hypertension (CBP ≥ 140/90 mmHg and ABP ≥135/85 mmHg) than workers who reported 40 or fewer weekly working hours.
The increases in prevalence remained after researchers adjusted for age, gender, education, occupation, lifestyle-related risk factors (e.g., alcohol intake and smoking), diabetes, family history of heart disease and job strain. After adjustments, the proportion of workers with masked and sustained hypertension was 51% and 33% greater, respectively, among those working 41 to 48 hours and 70% and 66% greater, respectively, among those working 49 or more hours.
Mixed results in previous studies on the relationship between long working hours and blood pressure were potentially due to smaller sample sizes, the use of different blood pressure measurement methods and lack of consideration of masked hypertension. Few prior studies assessed ambulatory blood pressure, defined as blood pressure that is assessed repeatedly over the day, which allows for screening of both masked and sustained hypertension.
Hypotheses on the relationship between long working hours and heart health include potential connections between long working hours and sleep deprivation, prolonged exposure to psychological work-related stress, or smoking and alcohol intake. But in this study, the association between long working hours and high blood pressure was independent of these other risk factors previously suspected of playing an influential role. Specifically, the current study adjusted for job strain (a measure of psychological stress) and lifestyle-related risk factors (i.e., tobacco use, body habitus, physical activity patterns and alcohol use).
Future research is needed to help clarify the pathways and mediators between long working hours and hypertension. For example, given the importance of cardiorespiratory fitness in determining one’s health trajectory and risk for cardiovascular disease/events, future studies assessing the association between long working hours and high blood pressure after adjustment for cardiorespiratory fitness (e.g., peak aerobic capacity) would add important, novel information to this area of study.
In pursuit of healthier workplaces
The study suggests that long working hours are a novel and modifiable risk factor for masked and sustained hypertension, which has clinical and public health policy implications. For example, health care providers might consider the benefits of ABP monitoring for individuals who report long working hours, and, if BP is elevated, workplace strategies aimed at reducing long working hours could be used to reduce the risk of cardiovascular disease/events associated with hypertension.
The study also highlights the importance of integrating the workplace into a preventive healthcare model, where risk factors are identified before adverse health events (e.g., heart attack) occur. In this context, strategies to build healthier workplaces can benefit employers and employees. Healthy, engaged employees are more productive and have lower absenteeism and healthcare costs. Moreover, evidence suggests that workplace health programs that combine biometric screenings with health risk assessments, behavioral counseling and incentives may result in favorable cost savings.
Employees are highly receptive to workplace health programs, and companies that intentionally and strategically invest resources in workplace health may be seen as employers of choice, experience less turnover, attract and retain top talent, and increase employee engagement and job satisfaction. The current study provides another example of the value of assessing an individual’s health profile in the workplace, and illustrates the opportunity to improve health proactively when a significant health risk is identified.