Systematic evidence grading evaluates multisystemic associations and risks of vitiligo

Area of Science:

• Dermatology and Autoimmunology
• Epidemiology
• Genetics

Background:

• Vitiligo is a chronic autoimmune skin condition with complex, often inconsistent, disease associations.
• Confounding factors complicate the interpretation of observational studies on vitiligo.
• Establishing a robust evidence hierarchy is crucial for understanding vitiligo's comorbidities.

Purpose of the Study:

• To conduct a comprehensive umbrella review and comparative analysis of observational studies on vitiligo.
• To evaluate the validity and strength of evidence for associations between vitiligo and various diseases/biomarkers.
• To establish an evidence hierarchy for vitiligo research to inform clinical management.

Main Methods:

• Umbrella review of 103 meta-analyses and 150 Mendelian randomization (MR) analyses.
• Evidence grading was applied to observational study findings.
• Comparative analysis across diverse research categories including cardiometabolism, cancer, autoimmune, and dermatological conditions.

Main Results:

• Seven convincing associations were identified.
• Increased vitiligo risk linked to fasting blood glucose, Graves' disease, thyroid antibodies, cataracts, and glaucoma.
• Vitiligo associated with decreased overall cancer risk and increased inflammatory bowel disease risk.

Conclusions:

• This study provides a graded evidence hierarchy for vitiligo associations.
• The protective effect of vitiligo against overall cancer risk is supported by robust meta-analysis and causal MR evidence.
• Findings may guide multidisciplinary management strategies for vitiligo patients.