According to observations in this study, glycated hemoglobin (HbA1c) variability may offer additional information for an optimized management of diabetes, especially in individuals within the target of HbA1c.

• A total of 101,533 people with type 2 diabetes without cardiovascular diseases were identified from a large database in order to determine the effect of HbA1c variability on cardiovascular diseases in persons within the recommended HbA1c target.

• Primary composite outcome (non-fatal myocardial infarction, non-fatal stroke, all-cause mortality) and an expanded composite outcome (non-fatal myocardial infarction, non-fatal stroke, coronary revascularization/reperfusion procedures, peripheral revascularization procedures, and all-cause mortality) were considered, as well as a series of specific cardiovascular complications.

• A link was found between HbA1c variability and all the outcomes considered.

• Findings corroborated the correlation between HbA1c variability and cardiovascular complications occurrence in both the subgroups of patients with a mean HbA1c ≤ 53 mmol/mol (recommended HbA1c target) or > 53 mmol/mol during the exposure phase.

• For primary outcome, for the expanded secondary outcome and for the stroke, there was a higher risk associated with HbA1c variability among people with mean HbA1c ≤ 53 mmol/mol, even though HbA1c remained at the target during the follow-up.