Epidemiology
Obesity (2008) 16 4, 859–868. doi:10.1038/oby.2007.139
Anthropometric Risk Factors for Colorectal Polyps in African-American Women
Lauren A. Wise1, Lynn Rosenberg1, Julie R. Palmer1 and Lucile L. Adams-Campbell2
- 1Slone Epidemiology Center at Boston University, Boston, Massachusetts, USA
- 2Division of Epidemiology and Biostatistics, Howard University Cancer Center, Washington, District of Columbia, USA.
Correspondence: Lauren A. Wise (lwise@slone.bu.edu)
Received 13 March 2007; Accepted 17 July 2007; Published online 24 January 2008.
Abstract
Objective:
Colorectal adenomas are thought to be precursor lesions to colorectal cancer, a leading cause of cancer incidence and mortality in African-American women. Studies suggest that obesity is associated with risk of adenomas in white women, but little is known about the relation in African-American women. We prospectively examined the association between selected anthropometric factors and colorectal polyps in African-American women.
Methods and Procedures:
Data were obtained from the Black Women's Health Study (BWHS), a prospective cohort study of African-American women. From 1997 to 2003, we followed 33,403 women aged 
30 years with no prior diagnosis of cancer or polyps. Cox regression was used to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for risk of polyps, with adjustment for potential confounders.
Results:
After 211,797 person-years of follow-up, 1,189 cases of colorectal polyps were reported. The IRR comparing women with a current BMI 35 to <25 kg/m2 was 1.35 (95% CI = 1.12–1.62), after adjustment for covariates including waist-to-hip ratio (WHR). Women who gained 30 kg since age 18 were 1.76 times as likely as those who gained <5 kg to report polyps (95% CI = 1.33–2.33). The IRR comparing the highest (0.87) to lowest (<0.71) quintiles of WHR was 1.26 (95% CI = 1.04–1.54), after adjustment for covariates including BMI. BMI at age 18, adult height, and waist circumference (BMI-adjusted) were not materially associated with risk. Results were similar among women with a recent endoscopy.
Discussion:
Weight gain and obesity in adulthood may increase the risk of colorectal polyps in African-American women.
