My overall level of enthusiasm is moderate. The manuscript is well-written, but the study design shows important limits, few subjects, no women, fixed order of tests, and results are not surprising.
I feel the authors need to explain a few more details of the study design such as:
- why did they decide not to administer an insulin bolus when in hyperglycemia?
- did subjects on CSII modify any of the settings during the tests? were any of them on hybrid closed-loop?
- No statistical analysis is described in the text and no statistics were reported in the tables.
Results: it is not surprising that patients had hyperglycemia after such a standard meal and no bolus. As such these results are clinically and scientifically not relevant. The only relevant data would be the ones regarding ketones, if only some kind of statistics was described... data are simply described.
I suggest the authors revise this part thoroughly and ad statistical data in the text and in the table.
Discussion: I would leave out the part on the hypothetical role of ketone bodies as these hypotheses do not apply to T1D.