Metformin use may prevent immune-mediated skin diseases in type 2 diabetes patients

The researchers followed metformin initiators (n = 234,585) and non-metformin initiators (n = 125,921) within 12 months of the antidiabetic drug until December 31, 2011. Hazard ratios for metformin initiators versus non-metformin initiators were estimated using Cox regression weighted for propensity score in intention-to-treat (ITT) and per-protocol (PP) analyses.

The researchers found the following:

• Hazard ratios for immune-mediated skin diseases (allergic contact dermatitis, urticaria, and psoriasis) were 0.930 and 0.930 in ITT and PP analyses, respectively. The hazard ratios for each specific outcome were all significantly below unity.
• The ITT and PP hazard ratios for androgen-mediated skin diseases (hidradenitis suppurativa, acanthosis nigricans, and acne) were 1.110 and 0.990, respectively. All hazard ratios were insignificant for each specific outcome except for acne in the ITT analysis (hazard ratio: 1.116).

Limitations of the study include possible disease misclassification and confounding by indication. Also, the analysis did not determine whether the use of the same set of confounders was adequate.

The researchers conclude, "Metformin use is associated with a remarkably lower risk of immune-mediated skin diseases but lacks a preventive effect on androgen-mediated skin diseases."

Reference:

Chin-Hsiao Tseng; Differential Effects of Metformin on Immune-Mediated and Androgen-Mediated Non-Cancer Skin Diseases in Diabetes Patients: A Retrospective Cohort Study. Dermatology 2023; https://doi.org/10.1159/000530077