Abstract
Background: Vascular ultrasound enables non-invasive assessment of lower-limb arterial morphology and hemodynamics and may identify vascular abnormalities associated with type 2 diabetes mellitus (T2DM). This study aimed to determine whether ultrasound-derived morphological and hemodynamic parameters differ between patients with T2DM and non-diabetic controls. Methods: PubMed, Web of Science, EMBASE, and the Cochrane Library were systematically searched for studies published within the preceding 10 years up to June 2026. Eligible studies were original publications that quantitatively compared lower-limb arterial morphology and/or hemodynamics between adults with T2DM and non-diabetic controls using ultrasound imaging. Four studies comprising 708 participants and 2069 artery-level assessments were included. Ultrasound parameters were meta-analyzed using random-effects models, and between-group differences were evaluated using standardized mean differences (SMDs). Results: The pooled analyses demonstrated no statistically significant differences between patients with T2DM and non-diabetic controls in either morphological (SMD 0.23, 95% CI −0.14 to 0.61; p = 0.227) or hemodynamic parameters (SMD −0.14, 95% CI −0.36 to 0.09; p = 0.227). Heterogeneity was observed in both the morphological and hemodynamic analyses (I2 = 93% and 83%, respectively). Conclusions: Based on the available evidence, the pooled analyses identified no statistically significant overall differences in lower-limb arterial morphological or hemodynamic parameters between patients with T2DM and non-diabetic controls. The available evidence is limited by heterogeneous imaging methods and correlated artery-level measurements. Prospective multicentre studies using standardized imaging protocols and segment-specific analyses are required to clarify the clinical value of ultrasound for detecting early lower-limb vascular dysfunction in T2DM.