COMMENTS AND RESPONSES Comment on: Harrison et al. b-Cell Function Preservation After 3.5 Years of Intensive Diabetes

Harrison et al. (1) analyzed pancre-atic b-cell function in drug-naïvepatients with type 2 diabetes before and 42 months after treatment with insu-lin plus metformin or a combination of metformin, glyburide, and pioglitazone. The pretreatment evaluation was not ex-actly “before ” the treatment. It was carried out after 3 months of the run-in period with insulin plus metformin therapy for all participants. The study is well de-signed, the analysis is appropriate, and the data are straightforward except for two potential drawbacks: absence of a wash-out period prior to the final meal test and failure to pay attention to alter-ation in insulin sensitivity caused by th