“We cannot ignore the negative health effects of shift work, including cardiovascular disease, diabetes, stroke and certain types of cancer,” says Durdana Khan, a doctoral student at the York Faculty of Health, an intern at the York Center for Aging and Research and Education. “Our study is the first to examine the association between shift work and frailty in middle-aged and older adults.” For the study, which will be published in the May issue of the Journal of Occupational and Environmental Medicine, Khan collaborated with York-based professors Heather Edgell, Hala Tamim and Michael Rotondi and Health Sciences North Research Institute immunologist and epidemiologist Chris Verschoor 48,000 participants across Canada from the Canadian Longitudinal Study on Aging and followed them after three years to measure frailty.
Frailty is defined as a person’s likelihood of illness and death. The researchers used an index that takes into account 52 factors that are likely to shorten lifespan, including depression, osteoarthritis, a history of heart attacks and mobility problems. Slightly frail people are people with at least five factors. With at least 11 factors, people would be classified in the “very frail” category. The study found that one in five adult Canadians was involved in shift work, defined as work that falls outside of a nine to five schedule. People who had a history of shift work had a higher likelihood of frailty compared to people who only worked during the day. More than one in four was slightly frail and seven percent were very frail. Women whose longest job was rotating shift work were particularly likely to be considered frail, with more than 31 percent classified as mildly frail and almost 11 percent as very frail.
Circadian rhythms are softened by sun exposure. When sunlight hits the eyes, signals are sent to the pineal gland in the brain that trigger certain hormones and responses that regulate alertness, mood, and appetite, and a lack of light triggers other responses. In shiftworkers, this process is dysregulated, and research suggests that this disorder can contribute to a variety of health problems. “Although these results are preliminary, they suggest that circadian disruption may play an important role in frailty, and this warrants further investigation,” says Khan.
This latest study builds on previous research by Khan and Edgell, which suggests shift work may be linked to delayed menopause. “The circadian rhythm affects your brain’s ability to control your hormones, which can affect your menopause,” Edgell explains. “So there are a lot of physiological changes that can occur because of shift work.”
While women were more likely to be frail, overall health research shows that women are more resilient to disease than men, so this study doesn’t necessarily indicate higher mortality. Still, it points to gender differences that should be considered as more women work outside of a nine-to-five schedule, says Khan, who adds that being in control of exercise and diet can combat some of the negative effects. “We cannot eliminate shiftwork, but we can reverse frailty to some degree,” she concludes. (ANI)
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)