We now have a lot of discussion about glycemic variability, Peter says. “But sometimes things are mixed up, and the low and high blood glucose indices do not demonstrate variability. Instead, they reflect the risk an individual has in terms of hypoglycemia – the acute risk – and hypoglycemia – the long-term risk. The two indices reflect this in an excellent way, but they are more reflective of exposure to high blood glucose and low blood glucose values. What Dr. Kovatchev has done with the two indices is to make blood glucose linear. But in terms of associated risk, the scale is not linear.”

To make good use of Dr. Kovatchev’s indices you need a lot of blood glucose tests. “My gut feeling is that you need a minimum of three tests per day to have good representative values on these indices,” Peter says.

How does this compare with the A1C? The problem with that standard test is that hypos can positively influence it, so it doesn’t reflect hyperglycemia properly.

“Therefore, the two low and high blood glucose indices are very well suited for patients who are testing regularly,” Peter added. “At least, they are much more meaningful than mean blood glucose values. But for patients who test only rarely or not regularly, the A1C is still the better choice.”

John tells me that Roche launched the Smart Pix in Europe in 2006 and in North America this June. It has a list price of $125 and is available through Disetronic and the diabetes product mail order distributors that carry Accu-Chek insulin pump products, including Liberty Medical Supply, Edgepark Medical Supplies, CCS Medical, and Gemco Medical. “And any of the companies that distribute Accu-Chek pump supplies can easily order the Smart Pix from us on behalf of their customers,” John adds.

My conclusion is that while the low and high blood glucose indices may or may not be the best way we currently have to measure glycemic variability, the Smart Pix – which incorporates both of these indices as well as the standard deviation – is the best way that frequent testers have to measure their levels. And only with such measures can we control our diabetes.