Left Ventricular Global Longitudinal Strain as a Marker of Subclinical Myocardial Dysfunction in Youths With Type 1 Diabetes Mellitus: An Updated Systematic Review and Meta‐Analysis

Aims To assess Left Ventricular Global Longitudinal Strain (LV GLS) in youths with type 1 diabetes mellitus (T1DM) compared with healthy controls, as a marker of subclinical myocardial dysfunction. Methods We searched MEDLINE, the Cochrane Library, Scopus and the Web of Science up to November 2025 for studies comparing speckle‐tracking‐derived LV GLS in paediatric T1DM and healthy controls. Random‐effects meta‐analyses focused on two‐dimensional LV GLS, with exploratory three‐dimensional analyses, vendor‐based subgroup analyses and meta‐regression for age, diabetes duration and HbA1c. Results Twenty studies met the inclusion criteria. Eighteen studies (1086 youths with T1DM, 935 controls) were included in the primary 2D LV GLS analysis. Compared with controls, youth with T1DM had significantly impaired 2D LV GLS (mean difference −2.87%, 95% CI −4.03 to −1.71), with substantial heterogeneity (I 2 = 96.2%). Exploratory 3D GLS analysis with three studies showed no significant between‐group differences, and meta‐regression revealed no associations with age, diabetes duration or HbA1c. Conclusion Children and adolescents with T1DM show impaired left ventricular longitudinal deformation despite preserved conventional systolic indices, indicating early subclinical myocardial dysfunction. However, given the substantial heterogeneity and low certainty of current evidence, future standardized longitudinal studies are warranted. Ultimately, with the increasing use of speckle‐tracking echocardiography, GLS may serve as a valuable tool for cardiovascular risk stratification in this population.