Association Between Obesity and Smoking and Risk for Colorectal Cancer Precursors: A Cross-Sectional Study
Introduction
Colorectal cancer (CRC) remains a significant public health concern, with early detection and prevention strategies playing a crucial role in reducing its impact. As part of ongoing efforts to understand the risk factors associated with CRC and its precursors, this study examined a diverse cohort of 47,875 individuals who underwent CRC screening. The objective was to explore the relationships between obesity, current smoking, and the prevalence of CRC precursors while accounting for various demographic and clinical variables. By investigating these associations, this study contributes to a deeper understanding of how lifestyle factors and individual characteristics might influence the development of CRC precursors, thereby aiding in the development of more targeted preventive measures.
Methods
This study was conducted on age-eligible individuals who underwent a colorectal cancer screening at Baylor College of Medicine. Logistic regression analysis was conducted to examine the associations between exposure variables (obesity and current smoking status) and the likelihood of being diagnosed with CRC precursors. The odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated to quantify the strength of these associations. Statistical significance was determined using p-values. The analysis was initially conducted without adjustment and then adjusted for potential confounding variables, including age, race/ethnicity, presence of CRC high-risk conditions, and quality of colonoscopy preparation.
Results
A total of 47,875 individuals (mean age 58.4 ±8.8) completed CRC screening (18,915 colonoscopies, 28,705 FITs, and 255 sigmoidoscopies). Obesity was observed in 4,328 (38.4%) individuals, and 1,582 (9.1%) reported that they were current smokers. In subgroup analysis, obesity prevalence for Non-Hispanic Whites was 33.3%, for Non-Hispanic Blacks 57.0%, Hispanic 42.2%, and Asian/Pacific Islanders 13.2%. A significantly higher prevalence of current smoking was observed for Non-Hispanic Blacks (14.1%), followed by Non-Hispanic Whites (8.5%), Hispanics (7.1%), and Asian/Pacific Islanders (5.1%). Among the 18,915 individuals who completed a colonoscopy, 6,135 (32.4%) were diagnosed as having CRC precursors. Logistic regression analysis revealed that compared to individuals with normal colonoscopies, obese patients and current smokers were significantly more likely to be diagnosed with CRC precursors (OR 1.5, CI 1.3-1.7, p<0.001; OR 1.6, CI 1.3-2.0) p<0.001, respectively). These findings remained significant after adjusting for age, race/ethnicity, presence of CRC high-risk conditions, and quality of colonoscopy preparation.
Conclusion
These results underscore the importance of obesity and current smoking status as potential risk factors for the development of CRC precursors, independent of other contributing factors. These findings emphasize the need for targeted interventions and health promotion strategies to address these risk factors and mitigate their impact on colorectal health within diverse populations.