Watch that hemoglobin A1C for blood vessel thickening

A recent paper published in Diabetes Care delivers a compelling message to be on the alert for elevations of hemoglobin A1C—even when glucose tolerance is normal. The authors set out to "identify which marker of glycemic control is most informative with respect to the variation of IMT in individuals with NGT." (IMT = intima-media thickness (thickening of the blood vessel walls) and NGT = normal glucose tolerance.) They found that "Only A1C was associated with IMT...whereas 1-h glucose was not informative." This is something of a wake-up call to respect that elevations in hemoglobin A1C (which we routinely test) are associated with degenerative vascular changes even when the glucose appears normal.