Shift Workers Face Nearly Double the Long-COVID Risk, Austrian-Spanish Research Finds
Published on 08/12/2026 at 06:51 | Redaktion boerse-global.de
The toll of night shifts may extend far beyond fatigue and disrupted sleep. A new collaboration between researchers at the Medical University of Vienna and the Barcelona Institute for Global Health (ISGlobal) has uncovered a striking link between working through the night and the likelihood of developing prolonged symptoms after a coronavirus infection.
Published in the Scandinavian Journal of Work, Environment & Health, the analysis draws on data from Catalonia's COVICAT study, which tracked 2,941 participants between 2021 and 2023. Of those, 1,899 had a confirmed SARS-CoV-2 infection, and roughly 14.9 percent — between 283 and 284 individuals — went on to develop what clinicians classify as Long-COVID.
The Numbers Behind the Risk
Employees who regularly worked night shifts showed an 88 percent higher risk of Long-COVID compared with their daytime-only counterparts, a figure expressed statistically as a relative risk of 1.88. The danger escalated with frequency: those pulling at least three night shifts per month saw their relative risk climb to 2.07.
Sleep quality emerged as an equally important variable. Workers suffering from chronic insomnia — regardless of their shift schedule — faced a 42 percent elevated risk (RR 1.42). But the most concerning finding came when the two factors converged. Night workers who also battled chronic insomnia saw their risk multiply by a factor of 2.7 (RR 2.69).
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Obesity Compounds the Danger
Physical health status appeared to amplify the effects of disrupted circadian rhythms. Among night shift workers who were also living with obesity, the relative risk surged to 3.77, suggesting that metabolic strain combined with irregular sleep-wake cycles creates a particularly vulnerable profile for post-infection complications.
Neurological symptoms proved to be the most common manifestation of Long-COVID in the study group, appearing in 54.4 percent of affected participants. Notably, the research found no evidence that night work increased the likelihood of contracting the virus in the first place. Instead, the data points to shift patterns influencing recovery trajectories rather than initial infection rates.
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The findings could carry meaningful implications for occupational health assessments and corporate wellness strategies, particularly as employers evaluate shift models and consider targeted support for workers whose schedules leave them more exposed to long-term health consequences.
