A healthy lifestyle index is associated with reduced risk of colorectal adenomatous polyps among non-users of non-steroidal anti-inflammatory drugs

In sickness and health? Examining the co-occurrence and concordance of healthy lifestyle behaviours among spouses in Namibia

OBJECTIVES

This study examines the extent to which healthy lifestyle behaviours co-occur in individuals. We also explore within-couples concordance in healthy lifestyle behaviours in Namibia.

STUDY DESIGN

Cross-sectional study.

METHODS

We used data from 910 couples (1820 individuals) who were interviewed in the Namibia Demographic and Health Survey conducted in 2013. We assessed five different healthy lifestyle behaviours (alcohol non-consumption, non-cigarette smoking, healthy diet, physical exercise, and normal body mass index). An individual healthy lifestyle index (HLI) was derived by summing values across the five behaviours, with a binary indicator categorising each individual's lifestyle behaviour as 'healthy' (HLI ≥ 3) or 'unhealthy' (HLI < 3). Multivariate logistic regression models were fitted to explore the association between binary indicators of men's and their female partner's healthy lifestyles.

RESULTS

About 48% of men and 57% of women had at least three co-occurring healthy lifestyle behaviours. A third of couples were concordant in reporting a healthy lifestyle (HLI ≥ 3), while 27% were concordant in reporting an unhealthy lifestyle (HLI < 3). In multivariate analysis, Namibian men were almost twice (aOR, 1.90; 95%CI, 1.43-2.52) as likely to have a healthy lifestyle if their female partner also had a healthy lifestyle, compared with those who had a female partner who had an unhealthy lifestyle, after adjusting for relevant individual, partner and household characteristics.

CONCLUSION

The observed co-occurrence of healthy lifestyle behaviours and spousal concordance suggests it may be beneficial to consider couples a target for intervention when aiming to promote healthy behaviours and reduce cardiovascular diseases in Namibia.

Derivation and validation of a nomogram incorporating modifiable lifestyle factors to predict development of colorectal adenomas after negative index colonoscopy

This retrospective cohort study aimed to identify baseline patient characteristics involving modifiable lifestyle factors that are associated with the development of colorectal adenomas, and establish and validate a nomogram for risk predictions among high-risk populations with negative index colonoscopy. A total of 83,076 participants who underwent an index colonoscopy at the Tianjin Union Medical Center between 2004 and 2019 were collected. According to meticulous inclusion and exclusion criteria, 249 subjects were enrolled and categorized into the primary and validation cohorts. Based on the primary cohort, we utilized the LASSO-Cox regression and the univariate/multivariate Cox proportional hazards (Cox-PH) regression parallelly to select variables, and incorporated selected variables into two nomogram models established using the multivariate Cox-PH regression. Comparison of the Akaike information criterion and the area under the receiver operating characteristic curve of the two models demonstrated that the nomogram model constituted by four covariates retained by the LASSO-Cox regression, including baseline age, body mass index, physical activity and family history of colorectal cancer (CRC) in first-degree relatives, performed better at predicting adenoma-free survival probabilities. Further validation including the concordance index, calibration plots, decision curve analysis and Kaplan-Meier survival curves also revealed good predictive accuracy, discriminating ability, clinical utility and risk stratification capacity of the nomogram model. Our nomogram will assist high-risk individuals with negative index colonoscopy to prevent colorectal adenoma occurrence and CRC morbidity with improved cost-effectiveness.

Dietary and lifestyle indices for hyperinsulinemia and colorectal cancer risk: a case-control study

BACKGROUND

The incidence of colorectal cancer (CRC) has increased in Iran, and determining the dietary patterns that can contribute to reducing or increasing the risk of CRC will help better control this disease. Therefore, in the current study, we assessed the association between the empirical lifestyle index for hyperinsulinemia (ELIH) and the empirical dietary index for hyperinsulinemia (EDIH) with the CRC odds.

METHODS

The present case (n = 71)-control (n = 142) study was carried out in several CRC surgical units of hospitals in Tehran, Iran. A semi-quantitative food frequency questionnaire containing 168 items was used to assess participants' dietary intakes. The EDIH and ELIH scores were calculated by food groups and some variables such as body mass index and physical activity. Logistic regression models were applied to evaluate the association between the EDIH and ELIH scores with CRC odds.

RESULTS

According to baseline features of the study participants, there were significant differences between the controls and cases in ELIH score, fiber intake, taking aspirin, and family history of CRC in first- and second-degree relatives. Also, we found that the odds of CRC increased significantly in the last tertile compared to the first tertile in EDIH and ELIH in the adjusted model (odds ratio (OR) = 3.12; 95% confidence interval (CI): 1.30-7.48 and OR = 4.72; 95% CI: 1.15-19.39, respectively).

CONCLUSIONS

In conclusion, the result of this study indicated that CRC odds was significantly greater in subjects with higher EDIH and ELIH scores. Also, according to the results of this study, lifestyle and diet with insulinemic potential can influence the CRC risk.

Combined Effect of Healthy Lifestyle Factors and Risks of Colorectal Adenoma, Colorectal Cancer, and Colorectal Cancer Mortality: Systematic Review and Meta-Analysis

Background

In addition to adiposity, lifestyle factors such as poor diet, low physical activity, alcohol intake and smoking are noted to be associated with the development of colorectal cancer (CRC). This study aims to investigate the association and dose-response relationship between adherence to a healthy lifestyle and CRC risk.

Methods

A systematic literature search was conducted in MEDLINE and EMBASE for studies examining multiple lifestyle factors with risk of CRC, incident colorectal adenoma (CRA), and CRC-specific mortality through June 2021 without restrictions on language or study design. Meta-analysis was performed to pool hazard ratios using random-effects model. Subgroup analyses were performed based upon study and sample characteristics. Random-effects dose-response analysis was also conducted for CRC risk to assess the effect of each additional healthy lifestyle factor.

Results

A total of 28 studies (18 cohort studies, eight case-control studies, and two cross-sectional study) were included. When comparing subjects with the healthiest lifestyle to those with the least healthy lifestyle, the pooled HR was statistically significant for CRC (0.52, 95% CI 0.44-0.63), colon cancer (0.54, 95% CI 0.44-0.67), rectal cancer (0.51, 95% CI 0.37-0.70), CRA (0.39, 95% CI 0.29-0.53), and CRC-specific mortality (0.65, 95% CI 0.52-0.81). The pooled HR for CRC was 0.91 (95% CI: 0.88-0.94) for each increase in the number of healthy lifestyles. The inverse association between healthy lifestyle and CRC risk was consistently observed in all subgroups (HR ranging from 0.26 to 0.86).

Conclusions

Adoption of a higher number of healthy lifestyles is associated with lower risk of CRC, CRA, and CRC-specific mortality. Promoting healthy lifestyle could reduce the burden of CRC.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=231398, identifier CRD42021231398.

Obesogenic environments and cardiovascular disease: a path analysis using US nationally representative data

INTRODUCTION

People living in obesogenic environments, with limited access to healthful food outlets and exercise facilities, generally have poor health. Previous research suggests that behavioral risk factors and indicators of physiological functioning may mediate this link; however, no studies to date have had the requisite data to investigate multi-level behavioral and physiological risk factors simultaneously. The present study conducted serial and parallel mediation analyses to examine behavioral and physiological pathways explaining the association between environmental obesogenicity and cardiovascular disease (CVD).

METHODS

This cross-sectional observational study used data from the 2012-2016 Health and Retirement Study, a representative survey of US older adults (n = 12,482, mean age 65.9). Environmental obesogenicity was operationalized as a combined score consisting of nine environmental measures of food and physical activity. CVD and health-compromising behaviors (diet, alcohol consumption, smoking, and exercise) were self-reported. Physiological dysregulation was assessed with measured blood pressure, heart rate, HbA1c, cholesterol levels, BMI, and C-reactive protein. The Hayes Process Macro was used to examine serial and parallel paths through health-compromising behaviors and physiological dysregulation in the environmental obesogenicity-CVD link.

RESULTS

People living in more obesogenic environments had greater odds of self-reported CVD (odds ratio = 1.074, 95% confidence interval (CI): 1.028, 1.122), engaged in more health-compromising behaviors (β = 0.026, 95% CI: 0.008, 0.044), and had greater physiological dysregulation (β = 0.035, 95% CI: 0.017, 0.054). Combined, health-compromising behaviors and physiological dysregulation accounted for 7% of the total effects of environmental obesogenicity on CVD.

CONCLUSION

Behavioral and physiological pathways partially explain the environmental obesogenicity-CVD association. Obesogenic environments may stymie the success of cardiovascular health-promotion programs by reducing access to resources supporting healthy lifestyles.

Associations of Evolutionary-Concordance Diet and Lifestyle Pattern Scores with Incident, Sporadic Colorectal Adenoma in a Pooled Case-Control Study

Differences in diet and lifestyle relative to those of our Paleolithic-era ancestors may explain current high incidences of chronic diseases, including colorectal cancer (CRC), in Westernized countries. Previously reported evolutionary-concordance diet and lifestyle pattern scores, reflecting closeness of diet and lifestyle patterns to those of Paleolithic-era humans, were associated with lower CRC incidence. Separate and joint associations of the scores with colorectal adenoma among men and women are unknown. To address this, we pooled data from three case-control studies of incident, sporadic colorectal adenomas (n = 771 cases, 1,990 controls), used participants' responses to food frequency and lifestyle questionnaires to calculate evolutionary-concordance diet and lifestyle pattern scores, and estimated the scores' associations with adenomas using multivariable unconditional logistic regression. The multivariable-adjusted odds ratios comparing those in the highest relative to the lowest diet and lifestyle score quintiles were 0.84 (95% confidence interval [CI] 0.62, 1.12; P_trend:0.03) and 0.41 (95% CI 0.29, 0.59; P_trend:<0.0001), respectively. The inverse associations were stronger for high-risk adenomas, and among those with both high relative to those with both low diet and lifestyle scores. These results suggest that more evolutionary-concordant diet and lifestyle patterns, separately and jointly, may be associated with lower risk for incident, sporadic colorectal adenoma.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.2002919 .

Individual and Joint Associations of Genetic Risk and Healthy Lifestyle Score with Colorectal Neoplasms Among Participants of Screening Colonoscopy

Genetic and lifestyle factors contribute to colorectal cancer risk. We investigated their individual and joint associations with various stages of colorectal carcinogenesis. We assessed associations of a polygenic risk score (PRS) and a healthy lifestyle score (HLS) with presence of nonadvanced adenomas and advanced neoplasms among 2,585 participants of screening colonoscopy from Germany. The PRS and HLS individually showed only weak associations with presence of nonadvanced adenomas; stronger associations were observed with advanced neoplasms (ORs, 95% CI, for highest vs. lowest risk tertile: PRS 2.27, 1.78-2.88; HLS 1.96, 1.53-2.51). The PRS was associated with higher odds of advanced neoplasms among carriers of any neoplasms (1.65, 1.23-2.22). Subjects in the highest risk tertile (vs. lowest tertile) of both scores had higher risks for nonadvanced adenomas (1.77, 1.09-2.86), for advanced neoplasms (3.95, 2.53-6.16) and, among carriers of any neoplasms, for advanced versus nonadvanced neoplasms (2.26, 1.31-3.92). Both scores were individually associated with increased risk of nonadvanced adenomas and, much more pronounced, advanced neoplasms. The similarly strong association in relative terms across all levels of genetic risk implies that a healthy lifestyle may be particularly beneficial in those at highest genetic risk, given that the same relative risk reduction in this group would imply a stronger absolute risk reduction. Genetic factors may be of particular relevance for the transition of nonadvanced to advanced adenomas. PREVENTION RELEVANCE: Genetic factors have strong impact on the risk of colorectal neoplasms, which may be reduced by healthy lifestyle. Similarly strong associations in relative terms across all levels of genetic risk imply that a healthy lifestyle may be beneficial due to higher absolute risk reduction in those at highest genetic risk.

Higher healthy lifestyle scores are associated with greater bone mineral density in middle-aged and elderly Chinese adults

This study examined the association between healthy lifestyle score (HLS), which contained 7 items (smoking, BMI, physical activity, diet, alcohol, sleep and anxiety) and BMD. Results showed HLS was positively associated with BMD at all studied sites, suggesting that healthier lifestyle patterns might be beneficial to bone health.

PURPOSE

Previous studies have reported favourable associations of individual healthy lifestyle factors with bone mineral density (BMD), but limited evidence showed the relationship of a combined healthy lifestyle score (HLS) with BMD. This study examined the association between the HLS and BMD.

METHODS

This community-based cross-sectional study included 3051 participants aged 40-75 years. The HLS contained 7 items (smoking, BMI, physical activity, diet quality, alcohol intake, sleep and anxiety). BMD values of whole body (WB), lumbar spine 1-4 (L_1-4), total hip (TH) and femur neck (FN) were measured using dual-energy X-ray absorptiometry.

RESULTS

After adjusting for potential covariates, HLS was positively associated with BMD at all studied sites (P-trend < 0.01). The mean BMDs were 2.69% (WB), 5.62% (L_1-4), 6.13% (TH) and 5.71% (FN) higher in participants with HLS of 6-7 points than in those with HLS of 0-2 points. The per 1 of 7 unit increase in the HLS was associated with increases of 7.63 (WB)-13.4 (TH) mg/cm² BMD levels at all sites. These favourable associations tended to be more pronounced in men than in women. Among the 7 items, physical activity contributed most to the favourable associations, followed by BMI, non-smoking and diet; the other three items played little roles. Sensitivity analyses showed that the significant associations remained after excluding any one of the 7 components or excluding fracture subjects at all sites.

CONCLUSION

Higher HLS was associated with greater BMD in middle-aged and elderly Chinese, suggesting that healthier lifestyle patterns might be beneficial to bone health.

A healthy lifestyle pattern has a protective association with colorectal polyps

BACKGROUND

Colorectal cancer is associated with lifestyle characteristics such as diet, physical inactivity, obesity, and smoking, but these are not incorporated in screening recommendations. Moreover, the joint association of these factors with various colorectal polyps is not established.

METHODS

A case-control study, among consecutive subjects aged 40-70 years, undergoing colonoscopy. Cases with colorectal polyps were compared with controls. Detailed information was gathered regarding polyp histology and anatomic location, demographics, medical history, anthropometrics, and lifestyle. The healthy lifestyle index was estimated as the sum of: non-smoking, maintaining a healthy weight, healthy diet, and physical activity.

RESULTS

A total of 788 participants were included (cases n = 403, controls n = 385). The healthy lifestyle index had a negative association with colorectal polyps (OR = 0.72, 95% CI 0.62-0.85, P < 0.001), both adenomas and serrated polyps (OR = 0.75, 0.64-0.89, and OR = 0.59, 0.44-0.79, respectively), and both proximal and distal adenomas (OR = 0.77, 0.62-0.95, and OR = 0.73, 0.59-0.90, respectively). Adherence to ≥ 2 healthy lifestyle components was strongly related with colorectal polyps (OR = 0.50, 0.34-0.75, P = 0.001). Abstinence from smoking, and a healthy diet were the factors most strongly associated with lower odds of colorectal polyps (OR = 0.58, 0.42-0.79, and OR = 0.61, 0.44-0.85, respectively).

CONCLUSIONS

Adherence to a healthy lifestyle (≥2 healthy lifestyle components) is inversely associated with colorectal polyps, especially serrated and distal polyps, with no dose-response association. Components most strongly associated with lower odds of colorectal polyps were maintaining a healthy diet and abstinence from smoking. Lifestyle-related characteristics may assist in risk stratification and are potential goals for colorectal neoplasia prevention.

Physically active individuals have a 23% lower risk of any colorectal neoplasia and a 27% lower risk of advanced colorectal neoplasia than their non-active counterparts: systematic review and meta-analysis of observational studies

BACKGROUND

Few studies have examined the associations between physical activity (PA), sedentary behaviour (SB) and risk of colorectal neoplasia (CN).

METHODS

We systematically searched Medline, Embase, PsyInfo, Cochrane and other sources from their inception to 30 September 2018 for cohort, case-control and cross-sectional studies that evaluated these associations in asymptomatic, average-risk subjects. Random-effect models were used to estimate relative risks (RRs) of any-type CN, advanced CN, and non-advanced CN, respectively, in individuals with the highest versus the lowest level of PA and SB. Dose-response analyses and subgroup analyses were conducted. The I² statistic was used to examine heterogeneity among studies.

RESULTS

We identified 32 observational studies, including 17 cross-sectional studies, 10 case-control studies and five longitudinal studies. PA (highest vs lowest) was inversely associated with risk for any-type CN (n=23 studies) and advanced CN (n=15 studies), with a RR of 0.77 (95% CI=0.71 to 0.83, I²=57.5%) and 0.73 (95% CI=0.63 to 0.82, I²=45.5%), respectively. There was no association between PA and non-advanced CN (n=5 studies). There was an as association between PA and any-type CN in both sexes, and also for the distal colon. We found no dose-response relationship between PA and any-type or advanced CN. Based on three studies identified, SB time (longest vs shortest) was associated with an increased risk of advanced CN (RR=1.24, 95% CI 1.04 to 1.49, I²=14.4%). No publication bias was detected by Begg's test.

CONCLUSION

We report a 23% lower relative risk of any type of CN and a 27% lower risk of advanced CN in people with the highest level of PA compared with those in the lowest.

Strong associations of a healthy lifestyle with all stages of colorectal carcinogenesis: Results from a large cohort of participants of screening colonoscopy

The risk of developing colorectal cancer (CRC) is associated with a wide range of dietary and lifestyle factors. The individual contribution of single modifiable factors, such as alcohol consumption, physical activity, smoking, body mass index (BMI) or dietary components, to the development of CRC has been investigated extensively, but evidence on their combined effect at various stages of colorectal carcinogenesis is sparse. The aim of our study was to analyze the association of a healthy lifestyle pattern with prevalence of early and advanced colorectal neoplasms. A total of 13,600 participants of screening colonoscopy in Saarland/Germany (mean age 62.9 years) who were enrolled in the KolosSal study (Effektivität der Früherkennungs-Koloskopie: eine Saarland-weite Studie) from 2005 until 2013 were included in this cross-sectional analysis. Dietary and lifestyle data were collected and colonoscopy results were extracted from physicians' reports. The association of an a priori defined healthy lifestyle score-including dietary intake, alcohol consumption, physical activity, smoking and BMI-with early and advanced colorectal neoplasms was assessed by multiple logistic regression analyses with comprehensive adjustment for potential confounders. Strong inverse dose-response relationships were observed between an overall healthier lifestyle pattern and presence of advanced colorectal neoplasms, nonadvanced adenomas and hyperplastic polyps (p value <0.0001 in all cases), with adjusted odds ratios (95% CI) for the highest compared to the lowest category of the healthy lifestyle score of 0.41 (0.30-0.56), 0.42 (0.33-0.54) and 0.39 (0.29-0.54) respectively. A healthy lifestyle is strongly associated with lower risk of all stages of colorectal neoplasms.

Adherence to Nutrition and Physical Activity Cancer Prevention Guidelines and Development of Colorectal Adenoma

Adherence to the American Cancer Society’s (ACS) Nutrition and Physical Activity Cancer Prevention Guidelines is associated with reductions in overall cancer incidence and mortality, including site-specific cancers such as colorectal cancer. We examined the relationship between baseline adherence to the ACS guidelines and (1) baseline adenoma characteristics and (2) odds of recurrent colorectal adenomas over 3 years of follow-up. Cross-sectional and prospective analyses with a pooled sample of participants from the Wheat Bran Fiber (n = 503) and Ursodeoxycholic Acid (n = 854) trials were performed. A cumulative adherence score was constructed using baseline self-reported data regarding body size, diet, physical activity and alcohol consumption. Multivariable logistic regression demonstrated significantly reduced odds of having three or more adenomas at baseline for moderately adherent (odds ratio [OR] = 0.67, 95% confidence intervals [CI]: 0.46–0.99) and highly adherent (OR = 0.50, 95% CI: 0.31–0.81) participants compared to low adherers (p-trend = 0.005). Conversely, guideline adherence was not associated with development of recurrent colorectal adenoma (moderate adherence OR = 1.16, 95% CI: 0.85–1.59, high adherence OR = 1.23, 95% CI: 0.85–1.79).

Association of dietary insulinemic potential and colorectal cancer risk in men and women

Background

Insulin response may be important in colorectal cancer development. Diet modulates insulin response and may be a modifiable factor in colorectal cancer prevention.

Objective

We examined associations between hyperinsulinemic diets and colorectal cancer risk with the use of an empirical dietary index for hyperinsulinemia (EDIH), a food-based index that characterizes dietary insulinemic potential on the basis of circulating C-peptide concentrations.

Design

Diet was assessed every 4 y with food-frequency questionnaires in 46,210 men (Health Professionals Follow-Up Study, 1986-2012) and 74,191 women (Nurses' Health Study, 1984-2012) to calculate EDIH scores. Multivariable-adjusted Cox regression was used to calculate HRs and 95% CIs for colorectal, proximal/distal colon, and rectal cancer risk.

Results

During 26 y of follow-up, we documented 2683 incident colorectal cancer cases. Comparing participants in the highest with those in the lowest quintiles, higher EDIH scores were associated with 33% (men: HR: 1.33; 95% CI: 1.11, 1.61; P-trend = 0.0005), 22% (women: HR: 1.22; 95% CI: 1.03, 1.45; P-trend = 0.01), and 26% (men and women: pooled HR: 1.26; 95% CI: 1.12, 1.42; P-trend <0.0001) higher risk of developing colorectal cancer. The positive associations were limited to the distal colon and rectum in men and to the distal and proximal colon in women; however, combined risk estimates were significant for all anatomic locations except for the rectum. For example, comparing participants in extreme EDIH quintiles, there was no significant association for proximal colon cancer in men (HR: 1.15; 95% CI: 0.84, 1.57; P-trend = 0.32), but the risk was elevated for distal colon (HR: 1.63; 95% CI: 1.14, 2.32; P-trend = 0.002) and rectal (HR: 1.63; 95% CI: 1.09, 2.44; P-trend = 0.01) cancer. Among women, the risk was elevated for proximal (HR: 1.28; 95% CI: 1.00, 1.63; P-trend = 0.03) and distal (HR: 1.46; 95% CI: 1.05, 2.03; P-trend = 0.03) colon cancer but not for rectal cancer (HR: 0.88; 95% CI: 0.60, 1.29; P-trend = 0.61).

Conclusion

The findings suggest that the insulinemic potential of diet may partly underlie the influence of dietary intake on colorectal cancer development. This observational study was registered at www.clinicaltrials.gov as NCT03364582.

Changes in the Inflammatory Potential of Diet Over Time and Risk of Colorectal Cancer in Postmenopausal Women

We examined the associations between changes in dietary inflammatory potential and risk of colorectal cancer (CRC) in 87,042 postmenopausal women recruited from 1993-1998 by the Women's Health Initiative, conducted in the United States. Food frequency questionnaire data were used to compute patterns of change in dietary inflammatory index (DII) scores and cumulative average DII scores over 3 years. Cox regression models were used to estimate hazard ratios for CRC risk. After a median of 16.2 years of follow-up, 1,038 CRC cases were diagnosed. DII changes were not substantially associated with overall CRC, but proximal colon cancer risk was higher in the proinflammatory-change DII group than in the antiinflammatory-stable DII group (hazard ratio = 1.32, 95% confidence interval: 1.01, 1.74). Among nonusers of nonsteroidal antiinflammatory drugs (NSAIDs) (Pinteraction = 0.055), the proinflammatory-stable DII group was at increased risk of overall CRC and proximal colon cancer. Also among nonusers of NSAIDs, risks of overall CRC, colon cancer, and proximal colon cancer were higher in the highest quintile compared with the lowest cumulative average DII quintile (65%, 61%, and 91% higher risk, respectively). Dietary changes toward, or a history of, proinflammatory diets are associated with an elevated risk of colon cancer, particularly for proximal colon cancer and among nonusers of NSAIDs.

An Empirical Dietary Inflammatory Pattern Score Enhances Prediction of Circulating Inflammatory Biomarkers in Adults

Background: Two indexes exist to describe dietary inflammatory potential: an empirical dietary inflammatory pattern (EDIP) composed of food groups as reported on a food-frequency questionnaire (FFQ) and a literature-derived dietary inflammatory index (DII) composed mainly of nutrients.Objective: We compared the ability of the 2 indexes to predict concentrations of inflammatory markers and hypothesized that the EDIP would be more predictive because it was derived on the basis of circulating inflammatory markers.Methods: Both EDIP and DII scores were calculated from FFQ data reported by 5826 women in the Nurses' Health Study II and 5227 men in the Health Professionals Follow-Up Study. We used multivariable-adjusted linear regression analyses to calculate relative differences in concentrations of 4 plasma inflammatory markers-C-reactive protein (CRP; milligrams per liter), interleukin 6 (IL-6; picograms per milliliter), tumor necrosis factor α receptor 2 (TNFαR2; picograms per milliliter), and adiponectin (nanograms per milliliter)-in quintiles of the dietary indexes.Results: Spearman correlations between the EDIP and DII scores were modest (r = 0.29 and 0.21 for women and men, respectively; all P < 0.0001). Higher scores on both dietary indexes were associated with higher concentrations of inflammatory markers, although they were associated with lower adiponectin concentrations and there was no association between the DII and adiponectin in men. For example, percentage differences in concentrations of biomarkers in quintile 5 generally were higher (lower for adiponectin) than in quintile 1 (for the EDIP and DII, respectively-women: CRP, +60% and +49%; IL-6, +23% and +21%; TNFαR2, +7% and +4%; adiponectin, -21% and -14%; men: CRP, +38% and +29%; IL-6, +14% and +24%; TNFαR2, +9% and +5%; adiponectin, -16% and -4%.)Conclusion: Despite design differences, the EDIP and DII both assess dietary inflammatory potential in men and women, with the EDIP showing a greater ability to predict concentrations of plasma inflammatory markers.

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

Associations of individual base excision repair (BER) genotypes with colorectal adenoma risk are unclear, but likely modest. However, genetic risk scores (GRS) that aggregate information from multiple genetic variants might be useful for assessing genetic predisposition to colorectal adenoma. We analyzed data pooled from three colonoscopy-based case-control studies of incident, sporadic colorectal adenoma (n = 488 cases, 604 controls) that collected blood for genotyping and extensive dietary and other data. We randomly split our population sample into training samples (half of the participants) and validation samples (the remaining participants) 10 times. Associations of 65 individual single nucleotide polymorphisms (SNPs) in 15 BER genes were assessed in the training samples and used to combine information from multiple risk variants into a BER GRS among the validation samples using unweighted and weighted methods. We also combined 15 extrinsic exposures with known pro- or antioxidant properties into an oxidative balance score (OBS). Associations of the BER GRS with colorectal adenoma, overall and jointly with the OBS, were assessed using multivariable logistic regression. The odds ratio for those in the highest relative to the lowest tertile of the weighted BER GRS was 2.07 (95% confidence interval, 1.26-3.40; p_trend  = 0.01). Relative to those with both a low GRS and a high (more antioxidant) OBS, the estimated direct association for those with both a high BER GRS and a low OBS was stronger than for those in other GRS/OBS categories. Our findings suggest that BER genotypes collectively may be associated with incident sporadic colorectal adenomas.

Case-control study of candidate gene methylation and adenomatous polyp formation

PURPOSE

Colorectal cancer (CRC) is one of the most common and preventable forms of cancer but remains the second leading cause of cancer-related death. Colorectal adenomas are precursor lesions that develop in 70-90 % of CRC cases. Identification of peripheral biomarkers for adenomas would help to enhance screening efforts. This exploratory study examined the methylation status of 20 candidate markers in peripheral blood leukocytes and their association with adenoma formation.

METHODS

Patients recruited from a local endoscopy clinic provided informed consent and completed an interview to ascertain demographic, lifestyle, and adenoma risk factors. Cases were individuals with a histopathologically confirmed adenoma, and controls included patients with a normal colonoscopy or those with histopathological findings not requiring heightened surveillance (normal biopsy, hyperplastic polyp). Methylation-specific polymerase chain reaction was used to characterize candidate gene promoter methylation. Odds ratios (ORs) and 95 % confidence intervals (95% CIs) were calculated using unconditional multivariable logistic regression to test the hypothesis that candidate gene methylation differed between cases and controls, after adjustment for confounders.

RESULTS

Complete data were available for 107 participants; 36 % had adenomas (men 40 %, women 31 %). Hypomethylation of the MINT1 locus (OR 5.3, 95% CI 1.0-28.2) and the PER1 (OR 2.9, 95% CI 1.1-7.7) and PER3 (OR 11.6, 95% CI 1.6-78.5) clock gene promoters was more common among adenoma cases. While specificity was moderate to high for the three markers (71-97 %), sensitivity was relatively low (18-45 %).

CONCLUSION

Follow-up of these epigenetic markers is suggested to further evaluate their utility for adenoma screening or surveillance.

Development and Validation of an Empirical Dietary Inflammatory Index

BACKGROUND

Knowledge on specific biological pathways mediating disease occurrence (e.g., inflammation) may be utilized to construct hypotheses-driven dietary patterns that take advantage of current evidence on disease-related hypotheses and the statistical methods of a posteriori patterns.

OBJECTIVE

We developed and validated an empirical dietary inflammatory index (EDII) based on food groups.

METHODS

We entered 39 pre-defined food groups in reduced rank regression models followed by stepwise linear regression analyses in the Nurses' Health Study (NHS, n = 5230) to identify a dietary pattern most predictive of 3 plasma inflammatory markers: interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor α receptor 2 (TNFαR2). We evaluated the construct validity of the EDII in 2 independent samples from NHS-II (n = 1002) and Health Professionals Follow-up Study (HPFS, n = 2632) using multivariable-adjusted linear regression models to examine how well the EDII predicted concentrations of IL-6, CRP, TNFαR2, adiponectin, and an overall inflammatory marker score combining all biomarkers.

RESULTS

The EDII is the weighted sum of 18 food groups; 9 are anti-inflammatory and 9 proinflammatory. In NHS-II and HPFS, the EDII significantly predicted concentrations of all biomarkers. For example, the relative concentrations comparing extreme EDII quintiles in NHS-II were: adiponectin, 0.88 (95% CI, 0.80, 0.96), P-trend = 0.003; and CRP, 1.52 (95% CI, 1.18, 1.97), P-trend = 0.002. Corresponding associations in HPFS were: 0.87 (95% CI, 0.82, 0.92), P-trend < 0.0001; and 1.23 (95% CI, 1.09, 1.40), P-trend = 0.002.

CONCLUSION

The EDII represents, to our knowledge, a novel, hypothesis-driven, empirically derived dietary pattern that assesses diet quality based on its inflammatory potential. Its strong construct validity in independent samples of women and men indicates its usefulness in assessing the inflammatory potential of whole diets. Additionally, the EDII may be calculated in a standardized and reproducible manner across different populations thus circumventing a major limitation of dietary patterns derived from the same study in which they are applied.

Construct validation of the dietary inflammatory index among postmenopausal women

PURPOSE

Many dietary factors have either proinflammatory or anti-inflammatory properties. We previously developed a dietary inflammatory index (DII) to assess the inflammatory potential of diet. In this study, we conducted a construct validation of the DII based on data from a food frequency questionnaire and three inflammatory biomarkers in a subsample of 2567 postmenopausal women in the Women's Health Initiative Observational Study.

METHODS

We used multiple linear and logistic regression models, controlling for potential confounders, to test whether baseline DII predicted concentrations of interleukin-6, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha receptor 2, or an overall biomarker score combining all three inflammatory biomarkers.

RESULTS

The DII was associated with the four biomarkers with beta estimates (95% confidence interval) comparing the highest with lowest DII quintiles as follows: interleukin-6: 1.26 (1.15-1.38), Ptrend < .0001; tumor necrosis factor alpha receptor 2: 81.43 (19.15-143.71), Ptrend = .004; dichotomized hs-CRP (odds ratio for higher vs. lower hs-CRP): 1.30 (0.97-1.67), Ptrend = .34; and the combined inflammatory biomarker score: 0.26 (0.12-0.40), Ptrend = .0001.

CONCLUSIONS

The DII was significantly associated with inflammatory biomarkers. Construct validity of the DII indicates its utility for assessing the inflammatory potential of diet and for expanding its use to include associations with common chronic diseases in future studies.

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

PURPOSE

Inflammation is a process central to carcinogenesis and in particular to colorectal cancer (CRC). Previously, we developed a dietary inflammatory index (DII) from extensive literature review to assess the inflammatory potential of diet. In the current study, we utilized this novel index in the Women's Health Initiative to prospectively evaluate its association with risk of CRC in postmenopausal women.

METHODS

The DII was calculated from baseline food frequency questionnaires administered to 152,536 women aged 50-79 years without CRC at baseline between 1993 and 1998 and followed through 30 September 2010. Incident CRC cases were ascertained through a central physician adjudication process. Multiple covariate-adjusted Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95 % confidence intervals (95 % CI) for colorectal, colon (proximal/distal locations), and rectal cancer risk, by DII quintiles (Q).

RESULTS

During an average 11.3 years of follow-up, a total of 1,920 cases of CRC (1,559 colon and 361 rectal) were identified. Higher DII scores (representing a more pro-inflammatory diet) were associated with an increased incidence of CRC (HRQ5-Q1 1.22; 95 % CI 1.05, 1.43; p trend = 0.02) and colon cancer, specifically proximal colon cancer (HRQ5-Q1 1.35; 95 % CI 1.05, 1.67; p trend = 0.01) but not distal colon cancer (HRQ5-Q1 0.84; 95 % CI 0.61, 1.18; p trend = 0.63) or rectal cancer (HRQ5-Q1 1.20; 95 % CI 0.84, 1.72; p trend = 0.65).

CONCLUSION

Consumption of pro-inflammatory diets is associated with an increased risk of CRC, especially cancers located in the proximal colon. The absence of a significant association for distal colon cancer and rectal cancer may be due to the small number of incident cases for these sites. Interventions that may reduce the inflammatory potential of the diet are warranted to test our findings, thus providing more information for colon cancer prevention.