The clinician and the study nurse are aware which spray is given, but subjects are blinded and additional insulin infusion on placebo day is done in a manner that the subjects remain blinded. The sprays are given on a randomized order. The randomization code was generated by a statistician using SAS, version 9.3 for Windows. The randomization block size was four and the method was permuted block randomization. The randomization was done for 16 subjects in case of discontinuations.