Response to Letter to the Editor from McKee and McGill: “Glycemic Control and Variability of Diabetes Secondary to Total Pancreatectomy Assessed by Continuous Glucose Monitoring”

Dear Editor, We thank McKee and McGill for their interest in our study (1). Below, we have addressed their comments and concerns. McKee and McGill ask for more “patient parameters” and “other important characteristics” describing the totally pancreatectomized (PX) persons compared with the individuals with type 1 diabetes (T1D). First, none of the patients were in active cancer treatment or had been diagnosed with disseminated cancer at the time of the study. Secondly, both plasma hemoglobin (mean ± SD 7.7 ± 0.7 vs 8.2 ± 0.5 mmol/L, P = .136) and creatinine (mean ± 76.4 ± 19.9 vs 71.8 ± 12.7 µmol/L, P = .546) levels (obtained at baseline) were similar in the 2 groups, and, thus, neither anemia nor impaired kidney function can be expected to have influenced hemoglobin A1c (HbA1c) levels in the groups. Also, the similar kidney function in the 2 groups does not point to a renal explanation of the lower insulin doses in the group of PX patients. In line with that, it is well known that PX patients require less exogenous insulin than individuals with T1D (2); presumably due their complete lack of pancreatic glucagon (3, 4), and perhaps also due to increased insulin sensitivity in these patients (5). The continuous glucose monitor (CGM) used in our study, the Medtronic iPro 2 professional, described by McKee and McGill as “a now outdated CGM device,” has been thoroughly validated and is still approved for clinical use. We observed no technical problems or issues with the data quality of the CGM readings; and, as such, the data generated can be considered accurate. The time in range (mean ± SD) was 58.0 ± 8.5% in the T1D group and 46.3 ± 12.6% in the PX group (P = .001). We also employed self-monitoring of blood glucose to substantiate our CGM findings, and we believe that these data support the aim of our study and provide completeness and transparency of the full data set. McKee and McGill consider the results from the control group as extraneous information not adding value to the manuscript. We believe that the data from our control group of matched healthy participants add context and perspective to the fluctuating blood sugar levels that PX patients and individuals with T1D are suffering from. Finally, we would like to thank McKee and McGill for pointing out 3 typing errors: (1) in the abstract, PX body mass index (BMI) is reported to be 34.4 (5.0) kg/m2. It should instead read 23.4 (5.0) kg/m2. (2) In the abstract, BMI is reported as mean with standard error of the mean in parenthesis; the number in parenthesis is in fact the standard deviation. (3) In the study participant section, the indication for pancreatectomy is missing for 1 patient; 5 patients were operated due to adenocarcinoma, not 4 as indicated. We apologize for any confusion these errors may have caused. Corrections have been made to the original article. Disclosure Summary: Authors have disclosed no conflicts of interest.