BACKGROUND:

To estimate the association between body-mass index (BMI: kg/m2) and colorectal cancer (CRC) screening among US adults aged >or= 50 years.

METHODS:

Population-based data from the 2001 Behavioral Risk Factor Surveillance Survey. Adults (N = 84,284) aged >or= 50 years were classified by BMI as normal weight (18.5-<25), overweight (25-<30), obesity class I (30-<35), obesity class II (35-<40), and obesity class III (>or= 40). Interval since most recent screening fecal occult blood test (FOBT): (0 = >1 year since last screening vs. 1 = screened within the past year), and screening sigmoidoscopy (SIG): (0 = > 5 years since last screening vs. 1 = within the past 5 years) were the outcomes.

RESULTS:

Results differed between men and women. After adjusting for age, health insurance, race, and smoking, we found that, compared to normal weight men, men in the overweight (odds ratio [OR] 1.25, 95% CI = 1.05-1.51) and obesity class I (OR = 1.21, 95% CI = 1.03-1.75) categories were more likely to have obtained a screening SIG within the previous 5 years, while women in the obesity class I (OR = 0.86, 95%CI = 0.78-0.94) and II (OR = 0.88, 95%CI = 0.79-0.99) categories were less likely to have obtained a screening SIG compared to normal weight women. BMI was not associated with FOBT.

CONCLUSION:

Weight may be a correlate of CRC screening behavior but in a different way between men and women.