Hyperglycemia: a bad signature on the vascular system.

Experimental work has clearly demonstrated that hyperglycemia is able to derail molecular pathways favouring oxidative stress, inflammation and endothelial dysfunction. Consistently, pooled analyses from prospective studies provide strong evidence that glycemic markers, namely glycated haemoglobin (HbA1c), predict cardiovascular risk, with an increase of about 18% in risk for each 1% absolute increase in HbA1c concentration, regardless of classical risk factors. Although the importance of hyperglycemic burden on cardiovascular phenotype, normalization of blood glucose levels in patients with long-standing hyperglycemia does not seem to reduce macrovascular complications. These data suggest that hyperglycemia may exert long-lasting detrimental effects on the cardiovascular system. This emerging phenomenon is defined metabolic or hyperglycemic memory to indicate a long-term persistence of hyperglycemic stress, even after blood glucose normalization. Here, we discuss clinical evidence and potential molecular mechanisms implicated in metabolic memory and, hence, diabetes-related cardiovascular complications.