Obesity and Physical Activity Related to Colorectal Adenoma by Anatomic Sites in Korea

Kim, Mi Kyung; Lee, Won Chul; Choi, Kyu Yong; Lee, Se Young; Kim, Sukil; Lee-Kim, Yang Cha; Meng, Kwang Ho

Abstract

Although the etiology of colorectal adenoma is not yet clear, numerous epidemiologic studies of colorectal adenoma(precursors of cancer) have shown a positive association with obesity and an inverse association with physical activity. The difference of the possible association of colorectal adenoma with body mass index(BMI= wt(kg)/ht2(m2) and physical activity(kcal/day) according to anatomic sites and gender was investigated in this case-control study. Between July 1994 and october 1998, 345 cases of patients(male 181, female 164) with pathologically confirmed incident colorectal adenoma and 1655 control subjects(male 598, female 1,057) were collected from Our Lady of Mercy Hospital, The Catholic University of Korea. After colonoscopy, self-reported weight and height, together with measures of intensity and time of exercise and lifetime job activity was obtained by the interviewers. Site- and gender-specific odds ratios relative to the lowest tertile of BMI and physical activity were determined using unconditional logistic regression after adjusting for potential confounders. Compared with subjects in the lowest terile of body mass index, multivariate-adjusted odds ratio of right colon for male and female in highest tertile were 1.49(95% CI:0.74-3.01) and 1.96(95% CI:0.93-4.15), respectively. Compared with subjects in the lowest tertile of physical activity, multivariate-adjusted odds ratio of right colon for male and female in highest tertile were 0.66(95% CI:0.35-1.26) and 0.83(95% CI:0.50-1.39), respectively. These results support a positive association between body mass index and occurrence or progression of adenoma in left colon and physical activity is associated with an elevated risk of right colon.