Night shifts linked to heart problems, study finds

‘Our findings have public health implications for preventing atrial fibrillation,’ researcher says

A new study has looked into the impact of night shift work on heart problems (Getty Images)

Night shifts are “significantly associated” with health issues to do with the heart, according to a new study.

The research found working late hours was linked with irregular and fast heart rate, with women potentially at greater risk.

Working night shifts also increased the risk of coronary heart disease (CHD), according to the paper published in the European Heart Journal.

Researchers have previously looked how night shift work impacts health, including a 2018 study finding an increased risk of CHD from rotating shift patterns, where night shifts are worked some of the time.

Previous studies have als shown that disruptions to sleep can lead to health problems because of the impact upon circadian rhythms - the body’s internal clock.

Researchers behind the latest study said they believe it is the first of its kind to test the association between night shift work and atrial fibrillation (AF) - a heart condition causing an irregular and often abnormally fast heart rate.

The study - which used information from 283,657 people in the UK Biobank database - said they found “both current and lifetime night shift exposure were significantly associated” with a risk of atrial fibrillation regardless of genetics.

“Night shift exposure also increased the risk of CHD (coronary heart disease) but not stroke or HF (heart failure). Whether decreasing night shift work frequency and duration might represent another avenue to improve heart health during working life and beyond warrants further study,” the paper said.

The study, which adjusted for factors that could affect the results, such as age, sex, socioeconomic status, blood pressure and sleep duration, found that people who currently worked night shifts on a usual or permanent basis had a 12 per cent increased risk of atrial fibrillation compared with people who only worked during the day.

The findings suggested that among people who worked an average of between three and eight night shifts a month for 10 years or more, the risk increased to 22 per cent compared with daytime workers.

One of the lead researchers said the findings suggest working night shifts less often and for shorter periods of time might be beneficial to heart health.

“Although a study like this cannot show a causal link between night shifts and atrial fibrillation and heart disease, our results suggest that current and lifetime night shift work may increase the risk of these conditions,” Professor Yingli Lu from the Shanghai Ninth People’s Hospital and the Shanghai Jiao Tong University School of Medicine in China said.

“Our findings have public health implications for preventing atrial fibrillation. They suggest that reducing both the frequency and the duration of night shift work may be beneficial for the health of the heart and blood vessels.”

Another researcher, Professor Lu Qi from the Tulane University School of Public Health and Tropical Medicine in New Orleans said gender and exercise also appeared to play a role.

Prof Qi said: “We found that women were more susceptible to atrial fibrillation than men when working night shifts for more than 10 years. Their risk increased significantly by 64 per cent compared to day workers.”

Previous research has also found women who worked night shifts had an increased risk of deveoping type 2 diabetes.

Additional reporting by Press Association