Response to Comment on: Lachin et al. (2007) The Hemoglobin Glycation Index Is Not an Independent Predictor of the Risk of Microvascular Complications in the Diabetes Control and Complications Trial: Diabetes 56:1913–1921, 2007
- David M. Nathan1,
- Saul Genuth2,
- Brandy Rutledge3 and
- John Lachin3
- 1Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
- 2Case Western Reserve University, Cleveland, Ohio
- 3Biostatistics Center, The George Washington University, Rockville, Maryland
- Address correspondence to John M. Lachin, The Biostatistics Center, 6110 Executive Blvd., Rockville, MD 20852. E-mail: jml{at}biostat.bsc.gwu.edu
Chalew et al. (1) have commented on our reassessment (2) of their hemoglobin glycation index (HGI), in which we show that the HGI is largely a function of A1C and that it does not—and in fact cannot—contribute independently to the risk of complications. Although we readily acknowledge that A1C only explains a modest fraction of the risk of diabetes complications, we continue to question whether the HGI alone, or in combination with mean blood glucose (MBG), represents a biological process that merits consideration.
The original premise underlying the derivation of the HGI is the putative existence of “substantial differences in the level of A1C …
