Published online Dec 7, 2013. doi: 10.3748/wjg.v19.i45.8349
Revised: September 3, 2013
Accepted: September 16, 2013
Published online: December 7, 2013
AIM: To examine whether visceral adipose tissue (VAT) serves as a risk factor for colorectal adenoma-early colorectal cancer (CRC) sequence.
METHODS: A retrospective case-control study was conducted with 153 patients with stage I CRC, age/sex-matched 554 patients with colorectal adenoma and 557 normal controls. All subjects underwent various laboratory tests, abdominal fat computed tomography (CT), and colonoscopy. VAT was defined as an intra-abdominal adipose tissue area measured by CT scan. Adipose tissue area was measured at the level of the umbilicus from CT scan. We used the lowest quartile of VAT and subcutaneous adipose tissue area as a reference group.
RESULTS: The body mass index (BMI), total cholesterol, fasting glucose and VAT areas were significantly different among normal, adenoma and CRC groups. The VAT area was 120.6 ± 49.0 cm2 in normal controls, 130.6 ± 58.4 cm2 in adenoma group and 117.6 ± 51.6 cm2 in CRC group (P = 0.002). In univariate analysis, increased BMI was a risk factor for CRC compared to control (P = 0.025). However, VAT area was not a risk factor for CRC compared to control. In multivariate analysis that adjusted for smoking, alcohol consumption and subcutaneous adipose tissue area, VAT area was inversely related to CRC, compared to the adenoma (OR = 0.53, 95%CI: 0.31-0.92, highest quartile vs lowest quartile).
CONCLUSION: Our study shows that visceral obesity is not a risk factor for early CRC. Visceral obesity might influence the normal-adenoma sequence but not the adenoma-early carcinoma sequence.
Core tip: This study showed that visceral obesity is not a risk factor for early colorectal cancer, although it is an independent risk factor for colorectal adenoma in previous studies. Therefore, these data suggest that visceral obesity might influence the normal-adenoma sequence but not the adenoma-early carcinoma sequence.