Do fluctuations in HbA1c increase the risk of diabetic retinopathy?

This study observed whether variation in HbA1c in an individual increases the risk of developing diabetic retinopathy.

Chronic hyperglycaemia (high blood glucose levels) can result in damage to small blood vessels, leading to the various vascular complications associated with diabetes. Diabetic retinopathy (DR) occurs when the small blood vessels located in the retina at the back of the eye become leaky or blocked, resulting in loss of sight if severe.

HbA1c levels give a patient an indication of their average blood glucose levels over the previous three months and, although a patient may have similar average HbA1c levels, the HbA1c levels may vary over a wide range. It is this long-term fluctuation in blood glcuose levels which may serve as an independent risk factor for DR.

This study involved 38,891 patients (52.3% males; 47.7% female) with childhood, adolescent or adult-onset type 1 diabetes. Patients were included in the study if they had at least one retinal examination and at least five HbA1c results prior to the first occurrence of retionopathy or last retinal examination.

The average duration of diabetes was 6.2 years. Patients were arranged into groups based on age of onset of diabetes, gender and average HbA1c (6.9-8.3%).

At ten years of diabetes duration, a higher average HbA1c was associated with a 3.1% higher risk of DR for every one mmol/mol increase in average HbA1c. HbA1c variability (large fluctuations in average HbA1c levels) were associated with an even greater risk of DR. However, the risk then decreased slightly with time.

Fluctuations in blood glucose levels can increase the risk of developing DR.

Other risk factors such as high blood pressure, abnormal levels of fat in the blood and ethnicity were not accounted for during grouping and so those factors may have influenced the development of DR.

Consult your doctor about the continuous management strategies which you can take to prevent long-term fluctuations in your blood glucose levels in order to lower your risk of developing DR.