[Abdominal obesity, insulin resistance, and the risk of colonic adenoma]

Abdominal obesity and hyperinsulinemia or insulin resistance are of interest in connection with colon carcinogenesis. We conducted a prospective case controlled study for the evaluation of relationship between abdominal obesity, insulin resistance, and colorectal adenoma.

Fifty patients with colorectal adenoma and fifty healthy subjects were included in this study. Total colonoscopic examinations were performed in all the subjects. Fasting blood sugar (FBS), insulin, homeostasis model assessment (HOMA-IR), triglyceride (TG), cholesterol (CROL), BMI (body mass index), WHR (waist hip ratio), percent body fat (PBF) and obesity degree (OD) were measured. HOMA-IR was considered to represent insulin resistance. Diabetic patients were excluded from this study.

There were no differences in sex, serum insulin, FBS, HOMA-IR, TG, CROL between adenoma and control group. Subjects with high BMI, WHR, percent body fat, and obesity were more likely to have colonic adenoma. Multiple logistic regression analysis after adjusting confounding factors, had revealed that WHR was the most important independent risk factor for colon adenoma.

Abdominal obesity was most closely related to colonic adenoma. However, insulin resistance was not related to colonic adenoma. A larger case controlled study is needed.