Having a hemoglobin A1c level above 7.5% has been found to be linked with stiffening of the aorta, the main artery in the body, in people with type 2 diabetes.

The aorta leads directly from the heart and is responsible for delivering blood to all the other arteries in the body. Aortic stiffness is linked with increased blood pressure (hypertension) and higher rates of death from heart disease.

Hemoglobin A1c is a measure of blood glucose control, with a lower A1c level corresponding with lower blood glucose levels.

The finding comes from a study by researchers at the Federal University of Rio de Janeiro in Brazil. The research involved following 417 participants with type 2 diabetes over an average period of 4.2 years. Over this period, aortic stiffness was determined by measuring carotid-femoral pulse wave velocity (cf-PWV) .

Doubling in risk of aortic stiffness

The researchers found that half (51%) of the patients with type 2 diabetes had persistent or worsening aortic stiffness and the risk of this was twice as high in patients with an A1c of 7.5% or above than for patients with an A1c below this level.

The researchers concluded that improved blood glucose control together with reduced blood pressure levels and heart rate were the most important factors towards preventing worsening stiffness of the aorta.

Reducing blood glucose levels

Whilst achieving a lower A1c level is linked, within this study, to a reduction in risk of stiffening of the aorta, it is important to note that blood glucose lowering strategies are best carried out in a way that does not increase the risk of severe hypoglycemia (very low blood sugar levels), which also carries an increased risk of death from heart disease.

Severe hypoglycemia can be brought on by over-aggressive blood glucose lowering strategies such as using too high doses of insulin, sulfonylureas or prandial glucose regulators (glinides). Where possible, use of lifestyle changes, such as reducing reliance on processed foods and making exercise part of each day, are effective ways of reducing blood glucose levels whilst reducing dependence on medications that can increase the risk of severe hypos.

Speak to your doctor if you are unsure what your A1c level is or if you have questions about how best to safely lower your blood glucose levels.

The study is published online, ahead of print, by the Diabetes Care journal.