Obesity Increases Risk of Psoriasis and Autoimmune Diseases, Suggests Research
Italy: Obesity is associated with a higher prevalence and risk of several autoimmune conditions, including psoriasis and rheumatoid arthritis, compared with normal body weight. A systematic review and meta-analysis found increased prevalence of rheumatoid arthritis and psoriasis, along with a higher risk of developing conditions such as rheumatoid arthritis, psoriasis, multiple sclerosis, and inflammatory bowel diseases (Crohn’s disease and ulcerative colitis). These findings highlight obesity as a significant risk factor for autoimmune disorders.
The findings were published in Obesity: A Research Journal by Ilaria Spatocco and colleagues from the Università degli Studi di Napoli Federico II, Italy. The study aimed to clarify the relationship between obesity and autoimmune diseases, an area where existing evidence has remained inconsistent despite the known proinflammatory state associated with excess body weight.
For this purpose, the researchers conducted a comprehensive systematic review and meta-analysis by searching PubMed and Embase databases. They identified studies that evaluated the association between obesity—defined as a body mass index (BMI) greater than 30—and the prevalence or incidence of autoimmune diseases, compared with individuals of normal weight (BMI less than 25). Out of 1,311 records screened, 26 studies were included in the final analysis, comprising 8 cross-sectional and 18 longitudinal studies.
The researchers reported the following findings:
- Obesity was associated with a higher prevalence of certain autoimmune diseases compared to normal weight.
- Individuals with obesity had significantly increased odds of rheumatoid arthritis and psoriasis.
- Obesity was also linked to a higher risk of developing autoimmune diseases over time.
- Longitudinal analysis showed an increased risk of rheumatoid arthritis, psoriasis, multiple sclerosis, and inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis.
- Overall, obesity was associated with a 41% higher risk of developing any autoimmune disease during follow-up.
These findings support the hypothesis that the chronic low-grade inflammation seen in obesity may contribute to immune system dysregulation, thereby increasing susceptibility to autoimmune disorders. The results also suggest that the relationship between obesity and autoimmunity is not limited to a single disease but spans multiple conditions.
Although the authors note that disease-specific conclusions remain limited due to variability among studies, the overall evidence consistently points toward obesity as an important risk factor in the development of autoimmune diseases.
The study carries important clinical and public health implications. It reinforces the need for effective obesity prevention and management strategies, not only to reduce cardiometabolic risk but also to potentially lower the burden of autoimmune diseases. Recognizing individuals with obesity as a higher-risk group for autoimmunity may help guide early monitoring and intervention efforts.
Overall, the findings add to the growing body of evidence linking metabolic health with immune function, emphasizing the broader impact of obesity on long-term health outcomes.
Reference:
Spatocco I, Mele G, De Rosa G, Fusco C, Ruggiero K, Pellegrini V, Carreras F, La Grotta R, Ceriello A, Procaccini C, Matarese G, Prattichizzo F, de Candia P. Obesity as a Risk Factor for Autoimmune Diseases: A Systematic Review and Meta-Analysis. Obesity (Silver Spring). 2026 Jan;34(1):36-50. doi: 10.1002/oby.70044. Epub 2025 Nov 4. PMID: 41186974; PMCID: PMC12724045.
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