A new study led by researchers at York University has found a link between shift work and frailty among middle-aged and older workers in Canada, especially for women on rotating shifts.
While there is a large body of research suggesting the disruptions to circadian rhythms that shift workers experience are linked to various illnesses, this study was the first to take a comprehensive or “holistic” look at the connection between shift work and frailty.
“We cannot ignore the negative health outcomes related to shift work, including cardiovascular diseases, diabetes, stroke and certain cancers,” says York Faculty of Health PhD student Durdana Khan, a trainee with the York Centre for Aging and Research and Education. “Our study is the first to investigate the relationship between shift work and frailty for middle-age and older adults.”
Back in the 1970’s I was transferred to the London bureau of Reuters News Service. I spent a year in London and learned many things, personal and professional. As the ‘new guy’ from the States, however, I was subject to shift work. As the news service runs round the clock, our bureau was staffed all 24 hours. It turned out to be very convenient to my superiors to slot me in to fill in for folks. So, in any week, I might work all three different shifts. I can honestly say that I have never felt so ‘messed up’ as I did when I was changing shifts.
Shift-work and irregular work schedules can cause several health-related issues and affect our defense against infection, according to new research from the University of Waterloo.
These health-related issues occur because the body’s natural clock, called the circadian clock, can be disrupted by inconsistent changes in the sleep-wake schedule and feeding patterns often caused by shift work. To study this, researchers at Waterloo developed a mathematical model to look at how a disruption in the circadian clock affects the immune system in fighting off illness.
“Because our immune system is affected by the circadian clock, our ability to mount an immune response changes during the day,” said Anita Layton, professor of Applied Mathematics, Computer Science, Pharmacy and Biology at Waterloo. “How likely are you to fight off an infection that occurs in the morning than midday? The answer depends on whether you are a man or a woman, and whether you are among quarter of the modern-day labour force that has an irregular work schedule.”
The researchers created new computational models, separately for men and women, which simulate the interplay between the circadian clock and the immune system. The model is composed of the core clock genes, their related proteins, and the regulatory mechanism of pro- and anti-inflammatory mediators. By adjusting the clock, the models can simulate male and female shift-workers.
The results of these computer simulations conclude that the immune response varies with the time of infection. Model simulation suggests that the time before we go to bed is the “worst” time to get an infection. That is the period of the day when our body is least prepared to produce the pro- and anti-inflammatory mediators needed during an infection. Just as importantly, an individual’s sex impacts the severity of the infection.
“Shift-work likely affects men and women differently,” said Stéphanie Abo, a PhD candidate in Waterloo’s Department of Applied Mathematics. “Compared to females, the immune system in males is more prone to overactivation, which can increase their chances of sepsis following an ill-timed infection.”
This time it’s personal. A hundred years ago, it seems (actually it was 1977), I worked for Reuters News Service. I had the good fortune, I thought, of being sent to London to experience the international news desk. That turned out to be a wonderful educational as well as professional experience. However, part of my deal was that since I was the Yank who was only there for a year, they used me to fill every staffing vacancy that came up. As a result I often worked two or three different shifts in a week. I have to tell you that I have never felt so discombobulated in my life. I would wake up and not know if it was morning or night. All my body rhythms got fried. So, I really related to the following study.
Researchers report metabolic disruptions often seen in shift workers are not influenced by the brain’s circadian rhythm, but by peripheral oscillators in the liver, gut and pancreas. Source: Washington State University.
Working night shifts or other nonstandard work schedules increases your risk of becoming obese and developing diabetes and other metabolic disorders, which ultimately also raises your risk of heart disease, stroke and cancer.
Exactly why this happens has been unclear, but a new study conducted at Washington State University (WSU) has brought scientists closer to finding the answer. Continue reading →
Since humans are fundamentally diurnal creatures, staying awake at night can significantly disrupt all of the body’s internal biological clocks. These disruptions are far from harmless: over the long term, they can lead to a high incidence of various health problems, such as metabolic or cardiovascular problems or even certain types of cancer.
Imagine being able to easily get over all of the discomfort and problems of jet lag or night-shift work. Science is not quite there, but recent work by Marc Cuesta, Nicolas Cermakian and Diane B. Boivin from the Douglas Mental Health University Institute and McGill University has opened new therapeutic avenues for improving the synchronization of the body’s different biological clocks.
Physiological changes over the course of a day are regulated by a circadian system comprised of a central clock located deep within the centre of the brain and multiple clocks located in different parts of the body.
This study, which was published in The FASEB Journal (published by the Federation of American Societies for Experimental Biology), included 16 healthy volunteers who were studied in temporal isolation chambers. These results show, for the first time, that the peripheral biological clocks located in white blood cells can be synchronized through the…