The evidence for the negative health impacts of shift work continues to mount, with a new study suggesting the practice increases the risk of ischaemic heart disease.
Researchers found that for every year a person spent working irregular or unusual hours such as rotating shifts, evening work or night work, their risk of developing coronary artery disease jumped by almost 1%.
Researchers analysed 21 studies which pooled together 320,002 participants with 19,782 cases of ischaemic heart disease.
Shift workers were found to be 13% more likely to develop ischaemic heart disease compared with daytime workers, the meta-analysis, published the Journal Occupational Medicine, said.
While the cause of the association is not established, researchers suspect the disruption of the normal sleep-wake cycle, the increased stress involved in shift work and unhealthy lifestyles often associated with shift work, could be contributing factors.
“This is the largest study about shift work and ischemic heart disease ever undertaken. This is also the first study to analyse the dose response relationship between shift work and ischaemic heart disease,” study author Professor Weihong Chen said.
“The number of deaths due to ischaemic heart disease has continued to rise with 7.6 million deaths in 2005 and 8.9 million people dying due to the condition in 2015.”
Professor Chen said employers should pay more attention to staff members who were experiencing symptoms of heart problems, as well as those with a family history of heart disease, and offer heart health checks.