Could metformin ease Sjögren disease? Early data sparks interest

A retrospective case-control study presented at the International Symposium on Sjögren's Disease in Paris found that patients with Sjögren disease (SjD) and type 2 diabetes who were taking metformin had notably milder disease markers compared to those not on the drug. Specifically, metformin users showed lower salivary gland focus scores and reduced eye dryness on objective measures — findings that were replicated in an independent external cohort and confirmed via meta-analysis.

Researchers believe metformin's anti-inflammatory and immunomodulatory properties — including its ability to downregulate the STAT4 immune pathway and improve mitochondrial function — may help dampen the immune activity that drives SjD. Still, experts caution that this is observational data, not proof of benefit.

Key Takeaways:

• Metformin users had significantly lower salivary gland focus scores (1.88 vs. 3.26), and only 16% had high focus scores (>3) vs. 40% in matched controls
• Ocular staining and van Bijsterveld scores were significantly lower in metformin users across both cohorts
• Some secondary outcomes — including unstimulated salivary flow and patient-reported dryness — did not favor metformin
• Causality cannot be established from cross-sectional data; randomized controlled trials are needed

Why it matters: Sjögren disease lacks disease-modifying therapies, making any promising treatment signal worth pursuing. If confirmed in trials, repurposing an already widely used, well-tolerated drug like metformin could be a meaningful step forward in SjD management.