Cardiovascular diseases (CVDs) are one of the most critical public health problems in the contemporary world because they are the leading cause of morbidity and mortality. Diabetes mellitus (DM) is one of the most substantial risk factors for developing CVDs. Glycated hemoglobin is a product of the non-enzymatic glycation of hemoglobin present in erythrocytes. The determination of the percentage of glycated hemoglobin (HbA1c) is commonly used in clinical practice to assess glycemic control in patients diagnosed with DM. This method is much more informative than repeated blood glucose tests, because the HbA1c value reflects the degree of glycemic control over the last three months. It is, therefore, not surprising that the HbA1c value correlates with the presence and severity of diabetes complications, including CVDs, in the population of diabetic patients. The purpose of this publication was to present the results of a literature review on the relationship between the HbA1c value in people without DM, the presence and severity of subclinical cardiovascular dysfunction, and the presence of clinically overt CVDs. The most important tools used to assess subclinical cardiovascular dysfunction included the measurement of intima-media thickness (IMT), especially carotid IMT (cIMT), arterial stiffness assessment by the measurement of pulse wave velocity (PWV), and ankle–brachial index (ABI). According to the results of the studies cited in this literature review, it can be concluded that there are certain relationships between HbA1c, the presence and severity of subclinical cardiovascular dysfunction, and the presence of clinically overt CVDs such as coronary heart disease, cerebrovascular disease, and chronic lower extremity ischemia in non-diabetic patients. It is worth noting, however, that the results of studies conducted so far in this area are not fully unambiguous. Further studies are needed to better understand the influence of additional factors on the relationship between HbA1c and cardiovascular dysfunction in non-diabetic patients.
