We examined a population of H pylori
infected dyspeptic workers, and found that the prevalence of duodenal ulcer was strongly increased in shift workers in comparison to day‐time workers; furthermore, a positive relationship between the number of nights worked per month and the risk of peptic ulcer was detected. This finding may have relevant implications in occupational medicine, since it identifies H pylori
positive dyspeptic shift workers as a high risk group for peptic ulcer disease. Because this disorder is an important cause of absence from work,5
strategies aimed at its prevention in high risk groups may have relevant clinical and economic implications. Further support to this consideration is given by the fact that the prevalence of H pylori
infection is probably increased in shift workers.6
We feel that treatment of infection is a better strategy for preventing peptic ulcer disease in shift workers. In fact, H pylori eradication is relatively easy, requiring a one week course of antibiotic therapy, and recurrences are rare after successful treatment. This approach does not necessarily require changes in work schedule, since in spite of the persistence of any co‐factor, the development of peptic ulcer is practically impossible in the absence of H pylori infection.
Thus, we recommend screening procedures for H pylori
infection for dyspeptic shift workers. According to current guidelines, infection in subjects less than 45 years old, without alarming symptoms, can be confidently eradicated without further invasive diagnostic procedures.7
In this context, occupational physicians may play a major role for the application of this preventive strategy in shift workers. The usefulness of this approach in day‐time workers is much less certain, because dyspeptic symptoms disappear after eradication only if they are induced by a duodenal ulcer;8
given the relatively low rate of duodenal ulcer in this group, the impact of screening and eradication is probably negligible in an economic perspective.
Previous studies on the relationship between peptic ulcer and shift work did not control for H pylori
this fact reduces the reliability of these data, since the disease is strongly linked to infection; thus, differences in the prevalence of infection between cases and controls may result in spurious associations. Furthermore, effective preventive measures cannot be taken without knowing H pylori
According to the accepted model of H pylori
related ulcer, the organism first colonises the gastric antrum, inducing the so‐called antrum predominant gastritis. This kind of gastritis increases acid output, which induces a gastric metaplasia in the duodenum; the presence of gastric mucosa in the duodenum allows colonisation of the organism, and the subsequent development of duodenal ulcer.9
Shift work may interact with this pathophysiological model. Indeed, long term stress and nocturnal sleep deprivation, typically associated with shift work,10
may increases gastric acid secretion,11
and reduce mucosal defence.12
The study has some limitations. In fact, we cannot exclude the possibility that uncontrolled factors increasing the rate of duodenal ulcer, such as genetic predisposition or associated diseases, may have affected our findings. Furthermore, shift workers are largely a self selected population and therefore inherent differences unrelated to shift work itself may be present.
In conclusion, this study supports the findings of previous studies that have reported a higher rate of duodenal ulcer in shift compared to day workers, and confirms that these results are not only due to the differential rates of H pylori infection in these two groups of workers. H pylori eradication, by reducing the risk of peptic ulcer in shift workers, may also have relevant economic consequences.