Effect of metformin on central arterial stiffness in individuals with type 2 diabetes mellitus: a systematic review and meta-analysis.

Type 2 diabetes mellitus (T2DM) is a global health problem linked to hyperglycemia and cardiovascular complications, including central arterial stiffness. Metformin, the first-line therapy for T2DM, has been suggested to provide vascular protection, although evidence on arterial stiffness is inconsistent. This study investigated the effect of metformin on central arterial stiffness through systematic searches of PubMed/MEDLINE, ScienceDirect, Cochrane, and Google Scholar. Three reviewers independently performed data extraction and quality assessment, and pooled analyses were conducted in RevMan 5.4.1 (PROSPERO 1135002). Results showed no significant difference in pulse wave velocity (PWV) between metformin (8.9-11.2 m/s) and comparison groups (8.0-11.8 m/s), with a pooled mean difference (MD) of 0.09 m/s (95 % CI -0.06 to 0.25; p = 0.23; I2 = 0 %). However, metformin was associated with significantly higher central systolic blood pressure (cSBP) compared with controls (MD 3.30 mmHg, 95 % CI 0.60 to 6.00; p = 0.02; I2 = 0 %). In conclusion, metformin does not significantly affect PWV but is linked to a modest increase in cSBP, highlighting the need for larger studies to clarify its vascular implications.