Impact of BMI on Psoriasis Severity and Systemic Inflammation: Clinical Implications

A pooled analysis of 18 randomized ixekizumab trials shows higher BMI is associated with greater psoriasis severity and increased systemic inflammation.

The analysis pooled data from more than 7,000 participants and assessed core endpoints, including PASI and systemic biomarkers.

Higher BMI correlated with worse PASI scores and with elevated CRP levels, indicating parallel escalation of cutaneous disease and systemic inflammation. These biomarker data provide an objective correlate to PASI and can help refine overall disease-severity assessment.

Obesity in the cohort was linked to an 11-fold higher prevalence of multimorbidity (72.2% vs. 6.5% for three or more conditions). Hypertension, hyperlipidemia, diabetes, cardiovascular disease, asthma, metabolic dysfunction–associated liver disease, and psoriatic arthritis were among the most frequent comorbidities—underscoring the broad comorbidity signal associated with higher BMI and the need to recognize multimorbidity in affected patients.

Weight reduction in the literature is associated with improvements in PASI and with better responses to systemic and biologic therapies; evidence suggests weight loss can also influence drug pharmacokinetics and therapeutic response.

Key Takeaways:

• A large pooled analysis demonstrates a graded relationship between higher BMI, worse PASI scores, and greater systemic inflammation.
• Patients with overweight and obesity—roughly three-quarters of the cohort—had higher disease severity and a markedly greater comorbidity burden.
• Integrating attention to weight and metabolic health into psoriasis care pathways is likely to improve disease control and help guide therapeutic decision-making.