Night Shift Workers with High Blood Pressure May Be at Increased Risk of Diabetes

Working night shifts can do a number on your sleep. Either you need to wake up sooner to get errands done during usual waking hours, the sun makes it difficult to sleep soundly, or it can be too loud to get into a long, deep sleep. A new study finds this may lead shift workers with one heart condition to be at higher risk of other conditions.

Research recently published in the Journal of the American Heart Association examined how many regular night shift workers with hypertension end up developing diabetes, coronary heart disease, or stroke. Such patients are classified as having cardiometabolic multimorbidity. The team found an uptick in the risk of these conditions for night workers with high blood pressure, particularly if the workers got either too much or too little sleep. This builds on research showing that night work can be detrimental to both healthy people and those with certain conditions, like those who already have diabetes. The findings could be of interest to millions of workers.


Dr. Yongping Bai, senior author and associate professor in the department of geriatric medicine at Xiangya Hospital of Central South University in China, explains, “Since shift work is increasingly common and hypertension is a leading risk factor for cardiometabolic multimorbidity, it is crucial to clarify the association between shift work and cardiometabolic multimorbidity risks.”

To study this link, the team examined data from nearly 37,000 UK Biobank participants. That’s a health database with long-term data on half a million residents of the UK. For this study, researchers included participants who had enrolled between 2006 and 2010 between the ages of 40 and 69. They were followed for just shy of 12 years on average. Their work schedules were considered, too, with night shift workers classified as anyone who worked during non-standard business hours, between 6 p.m. and 7 a.m.


The team found that those with high blood pressure who mostly or always worked night shifts had a 16% higher risk of developing diabetes, heart disease, or stroke, compared with day shift workers. The number of shifts impacted risk, too. For those who regularly worked one to 10 night shifts per month, there was a 14% increased risk of developing another cardiometabolic condition. Working more than 10 monthly night shifts bumped that up to 19%. The risk was there even if workers managed seven to eight hours of sleep per night, but it was worse if they got more or less sleep than that.

Our body’s circadian rhythm regulates when we should be awake and when we should be asleep, and it is typically guided by light and dark. However, that can be impacted by working at night and by mixing night and day shifts.

Girardin Jean-Louis, director of the Center for Translational Sleep and Circadian Sciences who was not involved in the study, says, “That process is inverted for shift workers. We can teach someone to completely become a night worker without comorbid conditions. But once you become habituated to that shift, you don’t want to go back to the day shift. That’s the problem. It’s the constant shifting.”


If you work the night shift, there are some things you can try to get solid sleep. Those include going to bed as soon as you get off work, when there is hopefully no sunlight just yet. If there is, try to find ways to block out that light, like driving home in sunglasses. If you can get your room as dark as possible, too, that would be helpful, as studies have found that even exposure to moderate light during sleep may increase diabetes risk. You should also avoid caffeine over the last several hours of your shift and let people know what your schedule is so they don’t wake you up when you need to be sleeping.

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