type 2 glucose lowering

New research from Harvard Medical School and Massachusetts General Hospital has suggested that the accuracy of the hemoglobin A1c test could be improved by taking the lifespan of red blood cells into consideration.

Millions of people with diabetes normally have an A1c test as a regular part of their diabetes monitoring. It is a reliable and cost-effective way of measuring how high or low someone’s blood glucose levels have been trending. The test works by measuring how much sugar has been bonded to red blood cells since they were produced.

However, while currently viewed as the gold standard for gauging long-term diabetes management, the research has suggested that the accuracy of the test could be improved. Even if two people have quite significantly different blood glucose levels, they may still score the same A1c result.

Red blood cells last for around 120 days on average, but factors such as stress, nutrition and disease can have an impact on their lifespan, and they also vary from person to person. The researchers therefore produced a mathematical formula to try and determine whether factoring in the age of the red blood cells influenced the accuracy of the A1c results.

Red blood cells are the main component in our blood, and work to carry oxygen from our lungs to the places where it is needed. The body constantly replaces these red blood cells, meaning that in any given blood sample, there could be any combination of new and old blood cells, which the researchers think could reduce the accuracy of the A1c tests.

Dr John Higgins, from Harvard Medical School and study author, said: “Like a water-soaked sponge that’s been sitting on the kitchen sink for days, older red blood cells tend to have absorbed more glucose, while newly produced red blood cells have less, because they have not been around as long.”

Their study involved more than 200 participants, whose HbA1c tests results were compared to the results obtained using their new formula which allowed them to factor in the age of the red blood cells.

The A1c results and the results from the new age-factored HbA1c results were compared to a true blood glucose level average in each patient, which was accurately recorded by a continuous blood glucose monitor (CGM).

When comparing the results, the researchers looked for ‘significant errors’, which they classed as a reading being 15mg/dL or more out. According to the study, a third of patients who are tested with the current A1c test may get results with a significant error. However, using their age-factored A1c test, the researchers claim that only one in ten tests were found to have a significant error.

“We think our approach will enable many patients and their doctors to do a better job controlling blood sugar levels, and reduce the long-term risks of heart attack, stroke, blindness and kidney failure,” Dr Higgins said.

While the study does suggest that including the age of red blood cells into the A1c test improves the accuracy of testing, more research is still required to authenticate the findings and ensure they are safe before it can be developed any further.

The findings were published in journal Science Translational Medicine.