Sodium Consumption Associated with Greater Odds of Developing Psoriasis

Dietary sodium consumption is linked to increased odds of psoriasis, according to recent findings, suggesting that those with psoriasis may consider lowering their intake of sodium to levels typically recommended for the general public.1

These findings were the result of a new analysis authored by a team led by Aheli Chattopadhyay, MD, from the department of dermatology at the University of California San Francisco.

“We hypothesized that populations who have a higher risk of salt-sensitive hypertension may also have a stronger association between dietary sodium and odds of psoriasis, including females and Black individuals,” Chattopadhyay et al. wrote. “We additionally hypothesized a stronger association between sodium intake and psoriasis in older adults; those with a diagnosis of hypertension, chronic renal failure or type 2 diabetes mellitus; or those with a higher genetic risk based on psoriasis polygenic risk score.”1

Given the lack of previous epidemiologic research specifically looking into links between between sodium intake and psoriasis, Chattopadhyay and colleagues’ research helps addresses dietary concerns for patients with this skin disease.2

Trial Design Details

The patients included in this cohort were recruited via the UK National Health Service in the period between 2006 - 2010. The investigative team implemented data which they drew from the UK Biobank, made up of a cohort of 468,913 individuals from England, Wales, and Scotland.

The team highlighted that, given the accuracy of 24-hour urine collection as a method for assessment of one’s dietary sodium consumption, the primary analysis would estimate 24-hour urine sodium as a proxy for sodium intake in participants’ diets. They did not include patients if they lacked data on spot urine sodium levels, variables related to the estimation of 24-hour urine sodium, or related types of covariates.

A single spot urine sample that was taken from each participant was used by the investigators. This sample was drawn at each subject’s initial assessment between 2006 - 2010. It was notably available for nearly all of the trial participants.

In their analysis, the research team applied the INTERSALT equation for the purposes of estimating study subjects’ 24-hour urine sodium excretion, as the equation incorporates age, sex, BMI, and levels of urine potassium, sodium, and creatinine. This method was noted as having previously been validated within the UK Biobank dataset.

Additionally, the investigators used a sensitivity analysis in their research. In this analysis, urine sodium levels were modeled directly as the exposure, without estimating 24-hour urine sodium.

Impacts of Dietary Sodium Intake

The investigative team determined psoriasis diagnoses based on the presence of ICD-10 code L40. There were 468,913 participants included in the study, among whom the mean age at recruitment was 57 years and 54% of which were listed as female.

Through the use of multivariable logistic regression models, the team demonstrated that for each 1-gram increase in participants’ estimated 24-hour urine sodium, psoriasis development odds rose by 18% (OR: 1.18, 95% CI: 1.14–1.21). This finding was adjusted for subjects’ age, race/ethnicity, sex, level of education, and socioeconomic status.

No substantial evidence was identified by the investigators of strong effect modification by various factors such as participants’ race/ethnicity, sex, polygenic risk score for psoriasis, age, or medical history of chronic kidney disease, hypertension, or type 2 diabetes. The researchers found that the NHANES dataset’s results further supported such conclusions.

Specifically, this dataset demonstrated that each additional gram of self-reported dietary sodium ingested by participants was found to be linked to a likelihood increase of examination-confirmed psoriasis (OR: 1.47, 95% CI: 1.19–1.83).

“Dietary recommendations are a high priority for patients with psoriasis, and future longitudinal and interventional studies should investigate whether changes in dietary sodium impact psoriasis, including further subgroup analyses to help identify which individuals with psoriasis may be most salt-sensitive,” they wrote.1

References

1. Chattopadhyay A, Ye M, Chiang B, Halezeroglu Y, Van Blarigan EL, Liao W, et al. Increased sodium consumption is associated with psoriasis: A population-based cohort study. J Eur Acad Dermatol Venereol. 2025; 00: 1–9. https://doi.org/10.1111/jdv.20540.
2. Ford AR, Siegel M, Bagel J, Cordoro KM, Garg A, Gottlieb A, et al. Dietary recommendations for adults with psoriasis or psoriatic arthritis from the medical Board of the National Psoriasis Foundation: a systematic review. JAMA Dermatol. 2018; 154(8): 934–950.