This is the first study to look into the link between working the night shift and developing atrial fibrillation
NEW DELHI — According to a recent study performed by a group of international experts, people who work night shifts are more likely to develop atrial fibrillation (AF), an irregular and frequently excessively rapid heart rhythm.
The finding of the research study, led by Professor Yingli Lu of Shanghai Ninth People’s Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai, China, and Professor Lu Qi of Tulane University School of Public Health and Tropical Medicine, New Orleans, USA, was reported in the European Heart Journal.
Interestingly, this is the first study to look into the connection between night shift jobs and AF.
‘More frequent night shifts mean greater risk of atrial fibrillation’
Researchers found that the longer and more frequently people worked night shifts during their careers, the greater their risk of AF. They used data from 283,657 persons in the UK Biobank database.
As per the study on atrial fibrillation, work on the night shift was also related to an increased risk of heart disease, but not stroke or heart failure.
In addition, the researchers looked into whether genetic predisposition to AF could play a role in the increased risk.
They assessed total genetic risk based on 166 genetic variants linked to the disease but found that the degree of genetic risk did not affect the relationship between working night shifts and the incidence of AF, regardless of whether participants had a low, medium, or high genetic risk.
While research like this cannot prove a direct relationship between night shift work and atrial fibrillation or heart disease, the findings imply that present and lifetime night shift employment may raise the risk of these diseases.
The study’s findings have implications for public health in terms of avoiding atrial fibrillation and related heart problems. The researchers also believe that lowering the frequency and length of night shift work may be advantageous to heart and blood vessel health.
The vital data for conducting study on atrial fibrillation
There were 286,353 persons in the survey who were either employed or self-employed. When they registered in UK Biobank, a total of 283,657 people did not have atrial fibrillation, and 276,009 did not suffer heart failure or stroke.
For 193,819 people without AF, information on genetic variations was available, and 75,391 of them completed an in-depth questionnaire regarding their lifetime occupation in 2015.
73,986 of the study’s participants who had a healthy heart without any disease and stroke at the time of enrollment submitted information on their work history. There were 5,777 AF instances throughout the course of a 10-year follow-up period.
Age, sex, ethnicity, education, socioeconomic position, smoking, physical activity, nutrition, BMI, blood pressure, sleep duration, and chronotype (whether someone was a ‘morning’ or an ‘evening’ person) were all taken into account when the researchers ran their analysis.
What did the researchers find?
They concluded that persons who worked night shifts on a regular or permanent basis had a 13% higher risk of AF than those who exclusively worked during the day. For those who worked night shifts for 10 years or more, the risk climbed to 18% after a decade.
When compared to daytime workers, the incidence of AF rose to 22% among those who worked an average of 3 to 8-night shifts per month for 10 years or more.
Compared to daytime workers, the risk of coronary heart disease increased by 22%, 37%, and 35% among individuals presently working night shifts, working night shifts for 10 years or more, and working 3 to 8-night shifts a month during their lifetime, respectively.
Pros and Cons of the study
The study’s scale, including precise information on almost 283,000 people, is a strength. Furthermore, this is the first study to relate these data to genetic information in a population with complete histories of present shift work and lifetime employment.
The study’s limitations include the fact that it cannot prove that shift work causes heart problems, only that it is associated with them; the researchers may have missed some cases of atrial fibrillation; lifetime employment of the individuals was assessed only when the people joined UK Biobank, was self-reported, and therefore, it may have changed or been prone to some errors. Besides, there may be unknown factors that may have influenced the results.
Moreover, because the participants in the UK Biobank were mostly white British, it’s unlikely that the findings can be applied to other ethnic groups.