Metabolic Correlates of Colon Neoplasia
Abstracts
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BACKGROUND: The insulin resistance, metabolic syndrome X of obesity comprises a cluster of symptoms including central or "visceral" distribution of fat, glucose intolerance, lipid abnormalities, hypertension and some cancers such as breast, prostate and colon cancer. Epidemiological studies have demonstrated relationships between body size and various cancers and studies in animals and tissue culture have implicated insulin-like growth factor 1 (IGF-1) in carcinogenesis. Because of the relationships between dietary fat, inflammation and adenocarcinoma of the colon, we hypothesized that components of syndrome X would be more prevalent in patients with colon neoplasia than in controls. METHODS: In this prospective study we used simple office-based anthropometric methods to assess body fat distribution and body composition in 479 (309 men) consecutive predominantly Caribbean black (397) patients having colonoscopy and blood chemistry including glucose and lipids. Height, weight, waist and hip circumference and sagittal abdominal diameter (SAD, a measure of visceral fat) were compared in patients without identifiable colon pathology (n = 157) and patients with diverticula (n = 103) and with polyps (n = 159) inflammation (n = 31) or adenocarcinoma (n = 29) verified by biopsy or resection. RESULTS: Age, fat mass and fat free mass were significantly higher in patients with inflammation and neoplasia than in controls (p < 0.01 - 0.004). In non-obese subjects (n = 166) SAD, waist circumference, blood sugar and serum triglycerides were statistically significantly higher in cases than controls corrected for age. Hypertension was more common in cases independent of sex, while diabetes was more prevalent in female cases than in controls. In multivariate logistic analysis, however, fat free mass, a measure of body size was the most powerful predictor of colon neoplasia (p < 0.006). CONCLUSION: Simple anthropometric measures of central fat distribution together with other components of syndrome X and fat free mass predict the presence of colon neoplasia. |