Introduction: Normoglycemic patients undergoing pancreaticoduodenectomy (Whipple procedure) often inquire whether they will be diabetic postoperatively. There is limited information on this issue. We therefore looked at a more subtle measurement of long-term glycemic control, hemoglobin A1c (HgbA1c), as a prognostic tool in predicting progression to diabetes post Whipple.
Patients and methods: A retrospective review over a 6-year period of all patients undergoing Whipple procedures at a single institution was conducted. In all, 27 patients had no prior history of diabetes, complete follow-up, and measured preoperative HgbA1c values. Postoperative diabetes was defined as the need for oral hypoglycemic agents or insulin. These charts were analyzed for progression to diabetes after Whipple.
Results: Of the 27 patients, 10 were considered to have postoperative diabetes. The average preoperative HgbA1c value for these patients was 6.3+/-0.66. This was statistically different from the 17 patients without postoperative diabetes (average HgbA1c 5.2+/-0.39, p<0.001). The positive predictive value, negative predictive value, sensitivity, and specificity were 82%, 94%, 90%, and 88%, respectively.
Conclusion: This study demonstrates that progression to diabetes is very unlikely after Whipple operation if the preoperative HgbA1c value is in the normal range. The apparent utility of HgbA1c in predicting postoperative diabetes in this small study suggests that this laboratory test may be very helpful in counseling patients for Whipple operation.