The effect of gastrojejunostomy on carbohydrate metabolism in patients with pancreatic cancer

Introduction
Impaired glucose metabolism and diabetes frequently accompany pancreatic cancer. In patients with unresectable disease, palliative gastrojejunostomy is commonly performed to relieve gastrointestinal obstruction; however, its metabolic consequences remain insufficiently understood.

Aim
To assess the effect of gastrojejunostomy on carbohydrate metabolism in patients with unresectable pancreatic cancer and normal body mass index (BMI).

Material and methods
About 85% of patients with pancreatic cancer have impaired glucose tolerance or type 2 diabetes, with co-occurrence of the two conditions being complex and multifactorial. Patients with unresectable pancreatic cancer commonly develop signs and symptoms of gastrointestinal obstruction; symptomatic treatment involves performing gastroenterostomy. The study enrolled patients hospitalised due to unresectable pancreatic head tumour who underwent palliative gastrojejunostomy. The study included patients with BMI ranging from 17.5 kg/m2 to 24.9 kg/m2. Blood plasma insulin and glucose concentrations were assessed before the procedure, on the 1st and 3rd day, and 4 weeks after the procedure. Furthermore, HOMA-IR and QUICKI insulin resistance measures were analysed. The control group comprised patients hospitalised due to unresectable pancreatic head tumour who underwent exploratory laparotomy without palliative gastrojejunostomy.

Results
The mean BMI of all the analysed individuals was 21.5 ±2.1 kg/m2. The mean baseline insulin concentration was 7.6 ±5.3 µU/ml, while the mean baseline glucose concentration was 140.2 ±49.9 mg/dl. Statistically significant decreases in both insulin and glucose concentrations were observed as early as on the 1st day after the procedure; the values gradually decreased. Four weeks after the operation, the mean insulin and glucose concentrations were 3.1 ±2.2 µU/ml and 91.2 ±23.9 mg/dl, respectively, in the study group. Statistically significantly reduced insulin resistance was observed, expressed by decreased HOMA-IR and increased QUICKI. No statistically significant differences between consecutive measurements were noted in the control group.

Conclusions
Gastrojejunostomy performed in patients with unresectable pancreatic head tumour and normal BMI had a significant impact on carbohydrate metabolism. The operation resulted in decreased glucose and insulin concentrations, and reduced insulin resistance. The results suggest a beneficial metabolic effect of gastrojejunostomy performed in patients with normal BMI and pancreatic cancer. No significant changes in glucose and insulin concentrations as compared to baseline values were noted in the control group, which excludes pancreatic cancer as the sole cause of observed changes in carbohydrate metabolism.