Just got back from beautiful, sunny San Diego where the American Diabetes Association held its annual scientific sessions. Don’t be jealous… four solid days of research symposia and presentations on the latest developments in diabetes left me with ZERO time to enjoy the great outdoors.
One of the reports that you might find particularly interesting was delivered by Dr. Viral Shah of the Barbara Davis Center in Colorado. Dr. Shah and his colleagues studied CGM (continuous glucose monitor) data in adults with type-1 diabetes to see if time-in-range (percent of the day with glucose between 70 and 180 mg/dl) can predict the risk of long-term complications. For decades, hemoglobin A1c has been the only metric associated with long-term health problems in people with diabetes. The problem with A1c is that it is a surrogate measure of one’s overall glucose average and fails to reflect the quality of one’s diabetes management (highs and lows can still produce a decent overall average). The reliability of A1c measurements is also affected by a myriad of blood abnormalities and may misrepresent the true average glucose in people from some ethnic groups.
CGM, by contrast, provides a direct measure of glucose levels. Software associated with CGM can generate averages over an extended period of time (similar to A1c), but it also reveals the degree of hyperglycemia and hypoglycemia that contributes to that average. Time-in-range, time-above-range and time-below-range statistics reflect both the overall average and the quality of glucose management. And it doesn’t require a blood draw or a visit to a lab.
The one thing A1c advocates have been hanging their hats on is the DCCT outcome which showed a direct relationship between A1c and the development of long-term complications such as retinopathy, nephropathy and neuropathy. But what if a CGM metric, such as time-in-range, could do the same thing? That’s what Dr. Shah wanted to find out. And guess what? It does.
Over seven years, study participants who developed retinopathy spent an average of 52% of time within the range of 70-180, whereas those who avoided retinopathy spent 62% of time in-range. A detailed analysis of the data showed that every 5% increase in time-in-range correlated with a 16% decrease in retinopathy risk. And when a tighter range (70-140) was used, the risk goes down 26% for every 5% increase in time-in-range.
So now we know. Improve your time-in-range and your risk for long-term complications goes down. Where does that leave the A1c? Who cares! Now we have something more meaningful to strive for. Please reach out to our team to discuss your time-in-range and develop customized strategies for getting it up there. Call +1 610-642-6055 or email email@example.com.