A Healthy Lifestyle Index Is Associated With Reduced Risk of Colorectal Adenomatous Polyps Among Non-Users of Non-Steroidal Anti-Inflammatory Drugs

Abstract

In a Columbia, South Carolina-based case-control study, we developed a healthy lifestyle index from five modifiable lifestyle factors (smoking, alcohol intake, physical activity, diet, and body mass index), and examined the association between this lifestyle index and the risk of colorectal adenomatous polyps (adenoma). Participants were recruited from a local endoscopy center and completed questionnaires related to lifestyle behaviors prior to colonoscopy. We scored responses on each of five lifestyle factors as unhealthy (0 point) or healthy (1 point) based on current evidence and recommendations. We added the five scores to produce a combined lifestyle index for each participant ranging from 0 (least healthy) to 5 (healthiest), which was dichotomized into unhealthy (0–2) and healthy (3–5) lifestyle scores. We used logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) for adenoma with adjustment for multiple covariates. We identified 47 adenoma cases and 91 controls. In the main analyses, there was a statistically nonsignificant inverse association between the dichotomous (OR 0.54; 95% CI 0.22, 1.29) and continuous (OR 0.75; 95%CI 0.51, 1.10) lifestyle index and adenoma. Odds of adenoma were significantly modified by the use of non-steroidal anti-inflammatory drugs (NSAIDs) (pinteraction=0.04). For participants who reported no use of NSAIDs, those in the healthy lifestyle category had a 72% reduction in odds of adenoma as compared to those in the unhealthy category (OR 0.28; 95%CI 0.08, 0.98), whereas a one-unit increase in the index significantly reduced odds of adenoma by 53% (OR 0.47; 95% CI 0.26, 0.88). Although these findings should be interpreted cautiously given our small sample size, our results suggest that higher scores from this index are associated with reduced odds of adenomas, especially in nonusers of NSAIDs. Lifestyle interventions are required to test this approach as a strategy to prevent colorectal adenomatous polyps.

DNA base excision repair genetic risk scores, oxidative balance, and incident, sporadic colorectal adenoma

“…Our findings regarding the overall OBS‐adenoma association are consistent with those reported in previous epidemiologic studies, which found inverse associations of oxidative balance scores (OBS) with colorectal adenoma, prostate cancer, and total cancer mortality . Of direct relevance to the present study, in an analysis of three pooled case‐control studies of incident sporadic colorectal adenoma ( n = 789 incident adenoma cases and 1,500 polyp‐free controls), the odds ratio comparing those in the highest relative to the lowest OBS tertile was 0.54 (95%CI 0.43‐0.69; p trend < 0.0001) .…”

Construct validation of the dietary inflammatory index among postmenopausal women

“…Higher scores of the DII towards more pro-inflammatory values were associated with higher levels of TNFα-R2 and the combined inflammatory biomarker score among non-users of NSAIDs, but not among regular users of NSAIDs. In two previous studies, (33, 34) Tabung and colleagues found similar trends in the association of a combined lifestyle index on colorectal adenomatous polyps, by NSAIDs use. In one study, higher scores (representing a healthier lifestyle pattern) were associated with lower odds of colorectal adenomas in non-users of NSAIDs, but not in users (33).…”

“…In two previous studies, (33, 34) Tabung and colleagues found similar trends in the association of a combined lifestyle index on colorectal adenomatous polyps, by NSAIDs use. In one study, higher scores (representing a healthier lifestyle pattern) were associated with lower odds of colorectal adenomas in non-users of NSAIDs, but not in users (33). In the other study examining the association between the DII and risk of colorectal cancer significantly higher risk was observed in non-users of NSAIDs but not in users (34).…”

The association between dietary inflammatory index and risk of colorectal cancer among postmenopausal women: results from the Women’s Health Initiative

“…The adverse effects of a pro-inflammatory diet on inflammation may be potentially masked by the stronger effects of NSAIDs among regular users. The anti-inflammatory effect of NSAIDs on the colonic epithelium could be so strong as to render inconsequential the relative contribution of dietary inflammatory potential, and thus a DII-CRC association would not be observed among NSAID users, yet would be strong among nonusers of NSAIDs(44–46). …”