A higher intake of salt - as measured by the concentration of sodium in urine - is associated with an increased likelihood of atopic dermatitis, says a study published in JAMA Dermatology. The researchers used data on the amount of sodium in urine samples from more than 215,000 people in the UK, collected in a previous study. The authors suggest that restricting salt intake "may be a cost-effective and low-risk intervention" for this skin disease.
![salty food](/sites/default/files/2024-06/comida-con-sal.jpg)
240605 sal dermatitis EN
Alberto Arnedo-Pena
Honorary Professor, Department of Health Sciences
The study is of particular interest as it studies a novel risk factor for a prevalent disease considered to have a multifactorial aetiology. However, we can make a number of considerations to assess its contribution:
- The study has a cross-sectional epidemiological design, i.e. disease and exposure are measured at the same time. Therefore, there is no temporal relationship and it is not possible to establish proof of causality between sodium intake and disease. This would require cohort studies, first the exposure (sodium intake) and then the occurrence of the disease (atopic dermatitis).
- The disease is measured in several ways: prevalent, active, severe, with long time periods related to many risk factors. In addition, atopic dermatitis does not have a laboratory diagnosis, its diagnosis depends on medical consultation, and there may be biases in access to medical care.
- Being a cross-sectional design, it does not measure disease risks, only associations from odds ratios. These resulting odds ratios are modest. The sizeable sample size of the population studied means that significance is achieved. However, with regard to the results of the univariate analysis (table 2) there are no significant associations, and in the sensitivity analysis there are no associations with active atopic dermatitis either.
- No risk factors were considered in the logistic regression models, including allergic diseases such as asthma, allergic rhinitis, food allergy, atopy, atopic dermatitis in childhood, family history of atopic dermatitis, history of respiratory infections, pneumonia, sinusitis or tobacco use.
In conclusion, this is an exploratory study with an interesting hypothesis and, given its limitations, the importance of sodium intake in the aetiology of atopic dermatitis deserves to be studied in more depth with cohort or experimental studies.
- Research article
- Peer reviewed
- Observational study
- People
Brenda M. Chiang et al.
- Research article
- Peer reviewed
- Observational study
- People