HbA1c increase is associated with higher coronary and peripheral atherosclerotic burden in non diabetic patients.

Background And Aims: Prediabetes is associated with an increased risk of developing diabetes and cardiovascular disease. Our objective was to examine the cardiovascular (CV) risk profile of non-diabetic patients with and without prediabetes according to HbA1c, using macroangiopathic imaging biomarkers.

Methods: Our population consisted of 272 non diabetic patients aged between 40 and 70 years, with a normal fasting plasma glucose (FPG <5.6 mmol/L) and at least 1 CV risk factor. Exclusion criteria were prior history of CV disease or clinical evidence of advanced renal disease. Prediabetes was defined as an HbA1c value of 5.7-6.4%. Coronary artery calcium (CAC) score as well as mean common carotid intima media thickness (IMT) and plaque presence were assessed using consensus criteria.

Results: CAC score was higher in the prediabetes group compared to non-prediabetic subjects (131.7 ± 295.6 vs. 62.4 ± 178.8 AU, p < 0.001). Prediabetic subjects had higher mean IMT than non-exposed subjects (0.77 ± 0.14 vs. 0.61 ± 0.15 mm, p < 0.001). The proportion of prediabetic patients with CAC = 0 was significantly lower compared to non-exposed subjects (35% vs. 63%, p < 0.01). In contrast, the proportion of patients with a CAC >400 was significantly higher in the prediabetes group (10% vs. 3%, p < 0.05). Moreover, carotid plaques were significantly more present in patients with prediabetes than in the normoglycemic subjects (p < 0.01). In a multiple linear regression, IMT was associated with HbA1c continuous levels (p < 0.001). In addition, logistic regression showed that higher HbA1c levels were associated with CAC and carotid plaques presence (p for trend for all < 0.001).

Conclusions: Among patients with normal fasting glucose, HbA1c increase is associated with higher coronary and peripheral atherosclerotic burden in non-diabetic patients.