Response to the Letter by Pfützner and Forst

Pfützner and Forst (1) report that they found no significant blood glucose (BG) differences between the arm and finger during 1) BG decrease induced by intravenous insulin injection, and 2) BG increase and decrease induced by a standardized meal in combination with subcutaneous insulin injection.

As previously suggested by Pfützner and Forst, the observed differences between our data and their observations are caused by differences in experimental design. Our study protocol aimed at rapid BG decreases and achieved a mean BG change at the finger (averaged over total decline) of 3 mg · dl⁻¹ · min⁻¹. Hypoglycemic values at the finger were reached faster after insulin injection. This velocity has not been repeated by Pfützner and Forst, as their mean rate of BG decline did not exceed 2 mg · dl⁻ · min⁻¹ during the first hour after insulin injection and fell below 1 mg · dl⁻¹ · min …