September 20, 2016
A1C Should Not Be the End-All
Again, diaTribe has touched on the right topic. For the FDA and many payers, A1c is currently the “gold standard” used to assess diabetes therapy. Even the many diabetes organizations recommend the A1c as the tool for diabetes diagnosis.
But A1c has limits: it cannot capture other critical outcomes that matter to patients on a daily basis. Low blood sugar (hypoglycemia) can be fatal, and yet, A1c tells us nothing about it. New therapies may dramatically improve quality of life, but those improvements won’t show up in an A1c value. Two people can have the exact same A1c value, but spend wildly different amounts of time at high and low blood glucose values.
Given recent improvements in glucose sensing devices and understanding of people living with diabetes, A1c should now be supplemented by other important tools.
Therapies that reduce hypoglycemia will dramatically help patients, even if they do not change A1c. In fact, reducing episodes of hypoglycemia could raise A1c levels but significantly reduce the risk of death, serious injury, or a trip to the ER. Fear of hypoglycemia also stands as the biggest barrier to tighter glycemic control.
The A1c of 7% could reflect 100% time-in-range or 18% time-in-range over a period of three months. We need a more nuanced understanding of blood glucose changes.
The accuracy of glucose sensors has improved dramatically in the past three years. Reliable sensors now exist that offer more comprehensive and actionable measurement of glucose than A1c or fingersticks.
Diabetes is an extremely burdensome, 24/7 condition that leads to many negative feelings (e.g., stress, guilt, failure, exhaustion, fear) and doubles the risk of depression. A1c does not capture how different therapies affect quality of life.
A1c is an average that does not capture many important variables, including time spent in different glucose ranges and glycemic variability. A single measure reflecting a two-to-three-month period is too crude to adequately characterize glycemic control that changes minute to minute, often unpredictably and dangerously (especially in insulin users).
The FDA has requested tighter accuracy ranges, but as of the current time has not implemented anything and is still using the old standards. Several diabetes test strip manufacturers have test strip accuracy improvements in place, but not in the manufacturing line because the FDA will not get off the dime. Even most of the European diabetes test strip manufacturers have the tighter accuracy ranges because they are already required to have the tighter accuracy.
Please take time to read the full article here as I only skimmed the surface.