INS and cystic fibrosis: As pulmonary function declines in CF, insulin resistance becomes more severe.2 Stable CF outpatients are evaluated for CFRD started age 10 with primary recommendation for 2-hour oral glucose tolerance test (OGTT).3 The recommended treatment for CFRD is insulin therapy, similar to type 1 diabetes mellitus, since oral hypoglycemic medications have been found to be ineffective.