Altered systematic glucose utilization after gastrectomy: correlation with weight loss

Abstract

Background: Although gastrectomy induces weight loss and improves glucose homeostasis, the mechanism is not clearly elucidated.

Objective: Weight loss after gastrectomy for gastric cancer may be the result from not only altered nutrition absorption but also systematic endocrinologic changes after bariatric-like surgery. No clinical studies have evaluated the altered glucose metabolism associated with postoperative weight loss in gastric cancer patients.

Setting: A retrospective analysis of a tertiary medical center.

Methods: We evaluated changes in 18 F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography and weight change in patients who underwent gastrectomy. Participants comprised initially overweight (body mass index ≥23 kg/m2), who underwent 18 F-fluorodeoxyglucose positron emission tomography/computed tomography at 6 to 12 months after gastrectomy for early gastric cancer (n = 149). Small bowel, subcutaneous white adipose tissue (WAT), and skeletal muscle glycolysis were semiquantified using positron emission tomography/computed tomography. Measures were bifurcated or combined into values that correlated with ≥5% weight loss.

Results: Weight (median decrement, -3.3 kg), cholesterol level (-15 mg/dL), and body fat (-26.1%) significantly decreased after surgery. Substantial weight loss was significantly correlated with increased small bowel uptake of 18 F-fluorodeoxyglucose (≥5% weight loss versus <5% weight loss: 1.91 versus 1.69). Patients with an increased bowel uptake showed an increase in WAT uptake (P = .01). Patients with both increased small bowel and WAT uptakes were significantly correlated with weight loss (odds ratio: 9.67, 95% confidence interval 2.65-35.22).

Conclusions: Patients with increased small bowel glycolysis and increased WAT uptake after gastrectomy are likely to lose weight. Altered glucose distribution contributes to improvement of the metabolic parameter after gastrectomy. We have shown evidence of bariatric surgery-like endocrinologic changes in gastric cancer patients who underwent gastrectomy.