Abdominal Fat Linked to Psoriasis Risk, Especially in Women, Suggests Research

Drawing from a dataset of over 336,000 white British participants in the UK Biobank, including 9,305 individuals with psoriasis, the researchers assessed 25 different measures of body fat using anthropometric, bioelectric impedance, and imaging-based techniques. The team also investigated how genetic predisposition to psoriasis might interact with fat distribution.

The study led to the following findings:

• Four central adiposity indicators—waist-to-hip ratio (OR 1.26), abdominal fat ratio (OR 1.24), total abdominal adipose tissue index (OR 1.22), and waist circumference (OR 1.23)—were strongly associated with psoriasis, with high statistical significance.
• The association between central fat and psoriasis was more pronounced in females, particularly in terms of visceral adipose tissue mass.
• A significant interaction was found between the waist-to-hip ratio and the full psoriasis polygenic risk score (PRS), which includes the HLA-C06:02 allele.
• When HLA-C06:02 was excluded from the PRS, the interaction with the waist-to-hip ratio was no longer significant, highlighting the allele’s pivotal role in linking adiposity to psoriasis risk.
• Waist-to-hip ratio showed a stronger association with psoriasis in individuals negative for the HLA-C*06:02 allele, indicating that central obesity may be a more critical risk factor in this subgroup.
• Percentage of body fat (a total adiposity measure) was also associated with psoriasis (OR 1.29). Still, it did not exhibit a significant interaction with genetic risk—an observation attributed to measurement limitations rather than biological irrelevance.

“Our research shows that where fat is stored in the body matters when it comes to psoriasis risk. Central fat — especially around the waist — seems to play a key role,” Dr. Ramessur wrote. He emphasized the importance of understanding these biological mechanisms, which remain incompletely defined.

“These findings have important implications for public health and clinical care,” the authors noted. “Waist-to-hip ratio could be a practical marker for identifying individuals at increased risk for psoriasis, including those who might develop more severe forms of the disease.”

In an accompanying commentary, Dr. Joel Gelfand of the University of Pennsylvania highlighted the potential relevance of these findings in the context of emerging therapies. He pointed to growing interest in GLP-1 receptor agonists, which may reduce visceral fat and modulate inflammatory pathways implicated in psoriasis.

While the study's reliance on self-reported and electronic health record diagnoses may introduce classification bias, sensitivity analyses supported the robustness of the results. However, the authors acknowledged that the findings may not be generalizable to non-white populations, warranting further research across diverse cohorts.

Reference: https://www.jidonline.org/article/S0022-202X(25)00391-4/fulltext