BackgroundType 2 diabetes is associated with an increased risk of developing cardiovascular events. Previous studies have reported that advanced glycation end products (AGEs) were related to cardiovascular events in type 2 diabetes. However, data on associations between long-term AGEs and cardiovascular events in type 2 diabetes are lacking. This study aimed to determine whether a long-time shift in the levels of serum AGEs is associated with cardiovascular events in patients with poorly controlled type 2 diabetes.MethodsTwo-time serum methyl-glyoxal-hydroimidazoline (MG-H1) levels were measured in 138 patients with type 2 diabetes whose mean glycated hemoglobin level was 10.1%. We categorized patients whose serum MG-H1 levels were < 2.8 µg/mL at both times as the continuous low MG-H1 group. The primary endpoints of this study were combined cardiovascular events, which were defined as heart disease, peripheral arterial disease, stroke, and all-cause death. Hazard ratios (HRs) for combined cardiovascular events with 95% confidence intervals (CIs) were calculated using the Cox proportional hazard models to compare the outcomes between the continuous low MG-H1 group and others.ResultsThe continuous low MG-H1 group was associated with a significantly lower risk than others in combined cardiovascular events after adjusting for possible confounders (HR: 0.50; 95% CI, 0.28–0.87; P = 0.02). Furthermore, the same relationship was observed in patients without a history of cardiovascular events.ConclusionsContinuous low serum MG-H1 levels are associated with a low frequency of diabetes-related complications in patients with poorly controlled type 2 diabetes.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12933-023-01882-9.