Objectives: We wanted to evaluate the relationship between obesity and left colonic adenomatous polyps in Korean adult men.
Methods: This study was conducted among 575 adults men (aged between 40 and 69), who had colonoscopy done from January to December 2002 during a routine health examination at Health Promotion Center, Ulsan University Hospital. The patients' colons were examined up to splenic flexure by using fiberoptic colonoscopy. A questionnaire survey on behavioral factors and physical measurements were also done. The body mass index (BMI) and waist-hip ratio (WHR) were used as the indices of obesity. The BMI was categorized into three levels: normal (BMI < or = 22.9), overweight (23 < or = BMI < or = 24.9), and obese (BMI > or = 25.0). The WHR was categorized into four levels with cut-off points at the 30th, 60th, and 90th percentile of the control group. Age, education, smoking, alcohol use and exercise were controlled for by performing multiple logistic regression analysis.
Results: There were 99 cases of colonic adenomatous polyps. Four hundred seventy six subjects with normal colonoscopy findings served as the control. The BMI and WHR were associated with the adenomatous polyps (odds ratio, 1.81 [95% CI=1.02-3.19] for a BMI > or = 25.0 as compared with a BMI < or = 22.9, odds ratio, 3.94 [95% CI = 1.77-8.77] for a WHR > or = 0.95 as compared with a WHR < or = 0.86). The BMI was not associated with the risk of adenomatous polyps after additional adjustment was made for the WHR, but the association between the WHR and adenomatous polyps was still positive and independent of the BMI (odds ratio, 4.15 [95% CI=1.63-10.59]).
Conclusions: The results support that obesity, and particularly abdominal obesity, can be associated with an increased risk of incurring colonic adenomatous polyps.