Shift workers are at higher risk of heart issues than people who work consistent hours, according to a new study.
Scientists compared the cardiovascular disease risk of warehouse workers who work shifts and compared it to their natural body clock.
It revealed that for every hour the natural body clock is out of sync with a person’s work rota, the risk of developing a heart health issue increases by 31 per cent.
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Scientists compared the cardiovascular disease risk of warehouse workers who work shifts and compared it to their natural body clock. It revealed that for every hour the natural body clock is out of sync with a person’s work rota, the risk of developing a heart health issue increases by 31 per cent (stock)
European researchers focused on ‘circadian misalignment’ — the difference between a person’s ‘social clock’ and ‘biological clock’.
When these two aspects of a person’s life do not align, a person suffers fatigue, also known as ‘social jetlag’.
Circadian rhythms are responsible for each person’s own daily cycle and determines if someone is a morning lark or a night owl.
Dr Gamboa Madeira, study author from the of the University of Lisbon, said: ‘We all have an internal biological clock which ranges from morning types, who feel alert and productive in the early morning and sleepy in the evening, to late types, for whom the opposite is true – with most of the population falling in between.
‘Circadian misalignment occurs when there is a mismatch between what your body wants (e.g. to fall asleep at 10pm) and what your social obligations impose on you (e.g. work until midnight).’
European researchers focused on ‘circadian misalignment’ — the difference between a person’s ‘social clock’ (e.g. work schedules) and ‘biological clock’. When these two aspects of a person’s life do not align, a person can suffer fatigue, also known as ‘social jetlag’
The team of researchers recruited 301 people who work as pickers at a warehouse for a retail outlet which is operational 24 hours a day.
Staff at the warehouse rotate through three different shifts, earlies (6am – 3pm), lates (3pm – midnight), and nights (9pm – 6am).
Questionnaires on lifestyle and measurements of cholesterol and blood pressure were taken for all the study’s participants.
It found most people’s circadian rhythm and work schedule were out of line by two hours, with 59 per cent of workers having social jetlag of two hours or less.
However, for 33 per cent of staff it was 2-4 hours, and in eight per cent it was four hours or more.
A higher level of social jetlag was significantly associated with greater odds of being in the high cardiovascular risk group, the researchers found.
The odds of being classified high cardiovascular risk increased by 31 per cent for each additional hour of social jetlag, even after adjusting for sociodemographic, occupational, lifestyle, and sleep characteristics and BMI.
Dr Madeira said: ‘These results add to the growing evidence that circadian misalignment may explain, at least in part, the association found between shift work and detrimental health outcomes.
‘The findings suggest that staff with atypical work schedules may need closer monitoring for heart health.
‘Longitudinal studies are needed to investigate whether late chronotypes cope better with late/night shifts and earlier chronotypes to early morning schedules, both psychologically and physiologically.’
