Dupuytren's disease is a connective tissue disorder that causes lumps to form in the palm of the hand. Usually the nodules grow into strands. The fingers, especially the pinky and ring finger, can no longer stretch properly and therefore often remain in a bent position.
Guillaume Dupuytren
Baron Guillaume Dupuytren was a French surgeon who described the condition in 1831. Although he was not the first to do so, he was the first to state that it was a contracture in the palmar aponeurosis. This is a hard band structure of connective tissue in the palm, which starts at the wrist and runs in separate strips to the base of the 5 fingers. The palmar aponeurosis acts as an extension of the tendon of a forearm muscle (the palmaris longus) and as a reinforcement for the skin of the palm.
This disease mainly occurs in people of North-Western European descent and therefore it is assumed that there is a genetic factor, a genetic predisposition. The disease is also called the Viking disease named, because its geographic distribution across Europe and Great Britain corresponds to the Viking migrations. The disease may have already occurred in the Celts (the "Celtic claw"), but is often referred to as coachman's hands.
Dupuytren's Causes
When it comes to the causes of Dupuytren's disease, not everything is clear and there are sometimes conflicting results. There is consensus about certain risk factors such as smoking, alcohol consumption, diabetes mellitus (DM) and the aforementioned genetic predisposition. There are indications about the influence of work that working with the hands (manual work, manual work) is a risk factor, but opinions are still divided on this. Recently, this was once again carefully examined in a cohort study by Van den Berge et al. (2023). The question was whether current exposure to manual labor is related to the development of Dupuytren's disease and whether it is possible to establish a dose-response relationship.
The design of the study
The study was designed as a population-based cohort analysis using data from the UK Biobank cohort. The UK Biobank Study is a large-scale, long-term research project designed to track the health of over 500.000 UK adults. The aim of the study is to learn more about the causes of disease and health, and to develop better treatments and prevention. Between 2006 and 2010, participants aged 40 to 69 years were included in the cohort. Various medical data have been collected from them. For the Dupuytren study, it was decided to look at participants of Northern European descent (because of the genetic component).
Outcome measure and exposure
The first outcome measure is the diagnosis of Dupuytren. For this, the link is sought with exposure to manual labour. The manual labor was viewed in two different ways for each participant: 1. the degree of manual labor in the current occupation and 2. a cumulative exposure to manual labor calculated on the basis of the work history and history.
For the calculation of the cumulative exposure, a score has been assigned to each occupation performed (more than 15 hours per week) based on the O*NET (Occupational Information Network) score for manual work. O*NET is an online database that contains information about more than 1000 professions and professional activities. This database was used to classify the occupations of the participants in this study and to assess their degree of manual labour. The cumulative exposure score was calculated by multiplying the scores of all occupations.
The studied group
The study included 196.265 participants who are currently performing manual labor and 96.563 participants were included in the dose-response group. A lot of information has been gathered about potentially confounding factors. Participants exposed to manual labor and those not exposed to manual labor were then matched. In the analysis for current manual labor, 26.667 exposed participants are matched with 100.213 non-exposed participants. The dose-response analysis included 12.312 manual labor exposed participants and 46.624 unexposed participants.
Results
The results show that participants whose current occupation usually or always involves manual labor more often suffer from Dupuytren's disease than participants whose occupation sometimes or never involves manual labour. The Odds Ratio is with 1,29 (OR=1,29, 95% CI 1,12 to 1,49, p < 0.001) significantly increased. In this study, the OR is a good measure of the relative risk.
There is also evidence of a positive dose-response relationship between the cumulative manual labor exposure score and Dupuytren's disease. For an increase of 750 points (standard O*NET score × years) in cumulative workload increases the likelihood of Dupuytren by 17% (OR = 1,17, 95% CI 1,08 to 1,27, p < 0.001). Because the incidence of Dupuytren in the general population is low (approximately 1%), the OR can also be seen here as the relative risk.
Bricklayer – cook – general practitioner – social worker
Someone who has worked as a bricklayer for 30 years has a cumulative score of 30 (years) times 92 (O*Net score) = 2760 and is therefore at a 17% higher risk of Dupuytren's disease than someone who has worked as a cook for 30 years ( 30 times 67 = 2010) and a 37% higher risk than a general practitioner who has worked for 30 years (30 times 42 = 1260) and 60% more than a social worker who has worked for 30 years (30 times 16 = 480).
Discussie
Prolonged manual labor is a risk factor for Dupuytren's disease with a clear dose-response relationship. How manual labor pathophysiologically leads to Dupuytren is not yet really clear. There is a local inflammatory process in which highly elastic myo-fibroblasts are stimulated to multiply and differentiate. This seems to happen, among other things, under the influence of cytokines produced by local immune cells. Both genetic predisposition and factors such as age, gender, smoking, alcohol consumption, diabetes and high cholesterol can contribute to the condition. One hypothesis is that mechanical loading of the palm can lead to changes in the vascular supply of the connective tissue with production of oxygen free radicals that promote the transition from fibroblasts to myo-fibroblasts. Further research is needed to learn more about this.
The researchers discuss the strengths and weaknesses of their study in the freely accessible article. They state that performing manual labor is a risk factor for Dupuytren's disease with a clear dose-response relationship. Therefore, they conclude that physicians should recognize the condition as work-related in some cases.
Source
van den Berge BA, Wiberg A, Werker PMN, Et al Dupuytren's disease is a work-related disorder: results of a population-based cohort study Occupational and Environmental Medicine Published Online First: 12 January 2023. doi: 10.1136/oemed-2022-108670