Objective To investigate the efficacy of raw corn starch (RCS) in clinical management of insulinoma-induced hypoglycemia.
Methods We retrospectively collected clinical data of insulinoma patients who received RCS-supplemented diet preoperatively, and analyzed the therapeutic effects of the RCS intervention on blood glucose control, weight change, and its adverse events.
Results The study population consisted of 24 case of insulinoma patients, 7 males and 17 females, aged 46.08 ± 14.15 years. Before RCS-supplemented diet, all patients had frequent hypoglycemic episodes (2.51 ± 3.88 times/week), concurrent with neuroglycopenia (in 83.3% of patients) and autonomic manifestations (in 75.0% of patients), with the median fasting blood glucose (FBG) of 2.70 [interquartile range (IQR): 2.50-2.90] mmol/L. The patients’ weight increased by 0.38 (IQR: 0.05-0.65) kg per month, with 8 (33.3%) cases developing overweight and 7 (29.2%) cases developing obesity. All patients maintained the RCS-supplemented diet until they underwent tumor resection (23 cases) and transarterial chemoembolization for liver metastases (1 case). For 19 patients receiving RCS throughout the day, the median FBG within one week of nutritional management was 4.30 (IQR: 3.30-5.70) mmol/L, which was a significant increase compared to pre-nutritional level [2.25 (IQR: 1.60-2.90) mmol/L; P = 0.000]. Of them, 10 patients receiving RCS throughout the day for over four weeks had sustained improvement in FBG compared to pre-treatment [3.20 (IQR: 2.60-3.95) mmol/L vs. 2.15 (IQR: 1.83-2.33) mmol/L; P = 0.000). Five patients who received RCS only at night also had a significant increase in FBG within one week of nutritional management [3.50 (IQR: 2.50-3.65) mmol/L vs. 2.20 (IQR:1.80-2.60) mmol/L; P = 0.000], but only one patient who continued to receive RCS for over 4 weeks did not have a significant improvement in FBG. No improvement in weight gain was observed upon RCS supplementation. Mild diarrhea (2 cases) and flatulence (1 case) occurred, and were relieved by reduction of RCS dose.
Conclusion The RCS-supplemented diet is effective in controlling insulinoma-induced hypoglycemia.

Key words: corn starch, hypoglycemia, insulinoma, nutrition therapy