Interaction between genes and macronutrient intake on the risk of developing type 2 diabetes: systematic review and findings from European Prospective Investigation into Cancer (EPIC)-InterAct

Background: Gene-diet interactions have been reported to contribute to the development of type 2 diabetes (T2D). However, to our knowledge, few examples have been consistently replicated to date.Objective: We aimed to identify existing evidence for gene-macronutrient interactions and T2D and to examine the reported interactions in a large-scale study.Design: We systematically reviewed studies reporting gene-macronutrient interactions and T2D. We searched the MEDLINE, Human Genome Epidemiology Network, and WHO International Clinical Trials Registry Platform electronic databases to identify studies published up to October 2015. Eligibility criteria included assessment of macronutrient quantity (e.g., total carbohydrate) or indicators of quality (e.g., dietary fiber) by use of self-report or objective biomarkers of intake. Interactions identified in the review were subsequently examined in the EPIC (European Prospective Investigation into Cancer)-InterAct case-cohort study (n = 21,148, with 9403 T2D cases; 8 European countries). Prentice-weighted Cox regression was used to estimate country-specific HRs, 95% CIs, and P-interaction values, which were then pooled by random-effects meta-analysis. A primary model was fitted by using the same covariates as reported in the published studies, and a second model adjusted for additional covariates and estimated the effects of isocaloric macronutrient substitution.Results: Thirteen observational studies met the eligibility criteria (n < 1700 cases). Eight unique interactions were reported to be significant between macronutrients [carbohydrate, fat, saturated fat, dietary fiber, and glycemic load derived from self-report of dietary intake and circulating n-3 (ω-3) polyunsaturated fatty acids] and genetic variants in or near transcription factor 7-like 2 (TCF7L2), gastric inhibitory polypeptide receptor (GIPR), caveolin 2 (CAV2), and peptidase D (PEPD) (P-interaction < 0.05). We found no evidence of interaction when we tried to replicate previously reported interactions. In addition, no interactions were detected in models with additional covariates.Conclusions: Eight gene-macronutrient interactions were identified for the risk of T2D from the literature. These interactions were not replicated in the EPIC-InterAct study, which mirrored the analyses undertaken in the original reports. Our findings highlight the importance of independent replication of reported interactions.

Consumption of Fish Is Not Associated with Risk of Differentiated Thyroid Carcinoma in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study

Background: Differentiated thyroid cancer (TC) is the most common endocrine cancer. Fish can be an important source of iodine and other micronutrients and contaminants that may affect the thyroid gland and TC risk.Objective: We prospectively evaluated the relations between the consumption of total fish and different fish types and shellfish and TC risk in the EPIC (European Prospective Investigation into Cancer and Nutrition) study.Methods: EPIC is a cohort of >500,000 men and women, mostly aged 35-70 y, who were recruited in 10 European countries. After a mean follow-up of 14 y, 748 primary differentiated TC cases were diagnosed; 666 were in women and 601 were papillary TC. Data on intakes of lean fish, fatty fish, fish products, and shellfish were collected by using country-specific validated dietary questionnaires at recruitment. Multivariable Cox regression was used to calculate HRs and 95% CIs adjusted for many potential confounders, including dietary and nondietary factors.Results: No significant association was observed between total fish consumption and differentiated TC risk for the highest compared with the lowest quartile (HR: 1.03; 95% CI: 0.81, 1.32; P-trend = 0.67). Likewise, no significant association was observed with the intake of any specific type of fish, fish product, or shellfish. No significant heterogeneity was found by TC subtype (papillary or follicular tumors), by sex, or between countries with low and high TC incidence.Conclusion: This large study shows that the intake of fish and shellfish was not associated with differentiated TC risk in Europe, a region in which iodine deficiency or excess is rare.

Measured Adiposity in Relation to Head and Neck Cancer Risk in the European Prospective Investigation into Cancer and Nutrition

Background: Emerging evidence from cohort studies indicates that adiposity is associated with greater incidence of head and neck cancer. However, most studies have used self-reported anthropometry which is prone to error.Methods: Among 363,094 participants in the European Prospective Investigation into Cancer and Nutrition study (EPIC) with measured anthropometry, there were 837 incident cases of head and neck cancer. Head and neck cancer risk was examined in relation to body mass index (BMI) [lean: <22.5 kg/m2, normal weight (reference): 22.5-24.9 kg/m2, overweight 25-29.9 kg/m2, obese: ≥30 kg/m2], waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR) using Cox proportional hazards models.Results: Among men, a BMI < 22.5 kg/m2 was associated with higher head and neck cancer risk [HR 1.62; 95% confidence interval (CI), 1.23-2.12)]; BMI was not associated with head and neck cancer among women. WC and WHR were associated with greater risk of head and neck cancer among women (WC per 5 cm: HR, 1.08; 95% CI, 1.02-1.15; WHR per 0.1 unit: HR, 1.64; 95% CI, 1.38-1.93). After stratification by smoking status, the association for WHR was present only among smokers (Pinteraction = 0.004). Among men, WC and WHR were associated with head and neck cancer only upon additional adjustment for BMI (WC per 5 cm: HR 1.16; 95% CI, 1.07-1.26; WHR per 0.1 unit: HR, 1.42; 95% CI, 1.21-1.65).Conclusions: Central adiposity, particularly among women, may have a stronger association with head and neck cancer risk than previously estimated.Impact: Strategies to reduce obesity may beneficially impact head and neck cancer incidence. Cancer Epidemiol Biomarkers Prev; 26(6); 895-904. ©2017 AACR.

Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma: a nested case-control study

BACKGROUND

Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking.

METHODS

We used a case-control study design nested within a large prospective cohort to assess the association between circulating levels of anti-lipopolysaccharide (LPS) and anti-flagellin immunoglobulin A (IgA) and G (IgG) (reflecting long-term exposures to LPS and flagellin, respectively) and risk of hepatocellular carcinoma. A total of 139 men and women diagnosed with hepatocellular carcinoma between 1992 and 2010 were matched to 139 control subjects. Multivariable rate ratios (RRs), including adjustment for potential confounders, hepatitis B/C positivity, and degree of liver dysfunction, were calculated with conditional logistic regression.

RESULTS

Antibody response to LPS and flagellin was associated with a statistically significant increase in the risk of hepatocellular carcinoma (highest vs. lowest quartile: RR = 11.76, 95% confidence interval = 1.70-81.40; P trend = 0.021). This finding did not vary substantially by time from enrollment to diagnosis, and did not change after adjustment for chronic infection with hepatitis B and C viruses.

CONCLUSIONS

These novel findings, based on exposures up to several years prior to diagnosis, support a role for gut-derived bacterial products in hepatocellular carcinoma development. Further study into the role of gut barrier failure and exposure to bacterial products in liver diseases is warranted.

Outdoor air pollution and risk for kidney parenchyma cancer in 14 European cohorts

Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor air pollution at the residence and the incidence of kidney parenchyma cancer in the general population. We used data from 14 European cohorts from the ESCAPE study. We geocoded and assessed air pollution concentrations at baseline addresses by land-use regression models for particulate matter (PM10 , PM2.5 , PMcoarse , PM2.5 absorbance (soot)) and nitrogen oxides (NO2 , NOx ), and collected data on traffic. We used Cox regression models with adjustment for potential confounders for cohort-specific analyses and random effects models for meta-analyses to calculate summary hazard ratios (HRs). The 289,002 cohort members contributed 4,111,908 person-years at risk. During follow-up (mean 14.2 years) 697 incident cancers of the kidney parenchyma were diagnosed. The meta-analyses showed higher HRs in association with higher PM concentration, e.g. HR = 1.57 (95%CI: 0.81-3.01) per 5 μg/m3 PM2.5 and HR = 1.36 (95%CI: 0.84-2.19) per 10-5 m-1 PM2.5 absorbance, albeit never statistically significant. The HRs in association with nitrogen oxides and traffic density on the nearest street were slightly above one. Sensitivity analyses among participants who did not change residence during follow-up showed stronger associations, but none were statistically significant. Our study provides suggestive evidence that exposure to outdoor PM at the residence may be associated with higher risk for kidney parenchyma cancer; the results should be interpreted cautiously as associations may be due to chance.

Ambient air pollution and primary liver cancer incidence in four European cohorts within the ESCAPE project

BACKGROUND

Tobacco smoke exposure increases the risk of cancer in the liver, but little is known about the possible risk associated with exposure to ambient air pollution.

OBJECTIVES

We evaluated the association between residential exposure to air pollution and primary liver cancer incidence.

METHODS

We obtained data from four cohorts with enrolment during 1985-2005 in Denmark, Austria and Italy. Exposure to nitrogen oxides (NO₂ and NO_X), particulate matter (PM) with diameter of less than 10µm (PM₁₀), less than 2.5µm (PM_2.5), between 2.5 and 10µm (PM_2.5-10) and PM_{2.5 absorbance} (soot) at baseline home addresses were estimated using land-use regression models from the ESCAPE project. We also investigated traffic density on the nearest road. We used Cox proportional-hazards models with adjustment for potential confounders for cohort-specific analyses and random-effects meta-analyses to estimate summary hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Out of 174,770 included participants, 279 liver cancer cases were diagnosed during a mean follow-up of 17 years. In each cohort, HRs above one were observed for all exposures with exception of PM_{2.5 absorbance} and traffic density. In the meta-analysis, all exposures were associated with elevated HRs, but none of the associations reached statistical significance. The summary HR associated with a 10-μg/m³ increase in NO₂ was 1.10 (95% confidence interval (CI): 0.93, 1.30) and 1.34 (95% CI: 0.76, 2.35) for a 5-μg/m³ increase in PM_2.5.

CONCLUSIONS

The results provide suggestive evidence that ambient air pollution may increase the risk of liver cancer. Confidence intervals for associations with NO₂ and NO_X were narrower than for the other exposures.

Dietary and lifestyle determinants of acrylamide and glycidamide hemoglobin adducts in non-smoking postmenopausal women from the EPIC cohort

PURPOSE

Acrylamide was classified as 'probably carcinogenic' to humans in 1994 by the International Agency for Research on Cancer. In 2002, public health concern increased when acrylamide was identified in starchy, plant-based foods, processed at high temperatures. The purpose of this study was to identify which food groups and lifestyle variables were determinants of hemoglobin adduct concentrations of acrylamide (HbAA) and glycidamide (HbGA) in 801 non-smoking postmenopausal women from eight countries in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

Biomarkers of internal exposure were measured in red blood cells (collected at baseline) by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) . In this cross-sectional analysis, four dependent variables were evaluated: HbAA, HbGA, sum of total adducts (HbAA + HbGA), and their ratio (HbGA/HbAA). Simple and multiple regression analyses were used to identify determinants of the four outcome variables. All dependent variables (except HbGA/HbAA) and all independent variables were log-transformed (log2) to improve normality. Median (25th-75th percentile) HbAA and HbGA adduct levels were 41.3 (32.8-53.1) pmol/g Hb and 34.2 (25.4-46.9) pmol/g Hb, respectively.

RESULTS

The main food group determinants of HbAA, HbGA, and HbAA + HbGA were biscuits, crackers, and dry cakes. Alcohol intake and body mass index were identified as the principal determinants of HbGA/HbAA. The total percent variation in HbAA, HbGA, HbAA + HbGA, and HbGA/HbAA explained in this study was 30, 26, 29, and 13 %, respectively.

CONCLUSIONS

Dietary and lifestyle factors explain a moderate proportion of acrylamide adduct variation in non-smoking postmenopausal women from the EPIC cohort.

Alcohol consumption and the risk of renal cancers in the European Prospective Investigation into Cancer and Nutrition (EPIC). Wozniak MB, Brennan P, Brenner DR, Overvad K, Olsen A, Tjønneland A, Boutron-Ruault MC, Clavel-Chapelon F, Fagherazzi G, Katzke V, Kühn T, Boeing H, Bergmann MM, Steffen A, Naska A, Trichopoulou A, Trichopoulos D, Saieva C, Grioni S, Panico S, Tumino R, Vineis P, Bueno-de-Mesquita HB, Peeters PH, Hjartåker A, Weiderpass E, Arriola L, Molina-Montes E, Duell EJ, Santiuste C, Alonso de la Torre R, Barricarte Gurrea A, Stocks T, Johansson M, Ljungberg B, Wareham N, Khaw KT, Travis RC, Cross AJ, Murphy N, Riboli E, Scelo G.Int J Cancer. 2015 Oct 15;137(8):1953-66. [Epub 2015 Apr 28]. doi: 10.1002/ijc.29559

Epidemiologic studies have reported that moderate alcohol consumption is inversely associated with the risk of renal cancer. However, there is no information available on the associations in renal cancer subsites. From 1992 to 2010, 477,325 men and women in the European Prospective Investigation into Cancer and Nutrition cohort were followed for incident renal cancers (n = 931). Baseline and lifetime alcohol consumption was assessed by country-specific, validated dietary questionnaires. Information on past alcohol consumption was collected by lifestyle questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated from Cox proportional hazard models. In multivariate analysis, total alcohol consumption at baseline was inversely associated with renal cancer; the HR and 95% CI for the increasing categories of total alcohol consumption at recruitment vs. the light drinkers category were 0.78 (0.62-0.99), 0.82 (0.64-1.04), 0.70 (0.55-0.90), and 0.91 (0.63-1.30), respectively, (ptrend = 0.001). A similar relationship was observed for average lifetime alcohol consumption and for all renal cancer subsites combined or for renal parenchyma subsite. The trend was not observed in hypertensive individuals and not significant in smokers. In conclusion, moderate alcohol consumption was associated with a decreased risk of renal cancer.

Polyphenol intake and cardiovascular risk factors in a population with type 2 diabetes: The TOSCA.IT study

BACKGROUND

The role of polyphenol intake on cardiovascular risk factors is little explored, particularly in people with diabetes.

AIM

To evaluate the association between the intake of total polyphenols and polyphenol classes with the major cardiovascular risk factors in a population with type 2 diabetes.

METHODS

Dietary habits were investigated in 2573 males and females participants of the TOSCA.IT study. The European Prospective Investigation on Cancer and Nutrition (EPIC) questionnaire was used to assess dietary habits. In all participants, among others, we assessed anthropometry, plasma lipids, blood pressure, C-reactive protein and HbA1c following a standard protocol. The USDA and Phenol-Explorer databases were used to estimate the polyphenol content of the habitual diet.

RESULTS

Average intake of polyphenols was 683.3 ± 5.8 mg/day. Flavonoids and phenolic acids were the predominant classes (47.5% and 47.4%, respectively). After adjusting for potential confounders, people with the highest intake of energy-adjusted polyphenols (upper tertile) had a more favorable cardiovascular risk factors profile as compared to people with the lowest intake (lower tertile) (BMI was 30.7 vs 29.9 kg/m², HDL-cholesterol was 45.1 vs 46.9 mg/dl, LDL-cholesterol was 103.2 vs 102.1 mg/dl, triglycerides were 153.4 vs 148.0 mg/dl, systolic and diastolic blood pressure were respectively 135.3 vs 134.3 and 80.5 vs 79.6 mm/Hg, HbA1c was 7.70 vs 7.67%, and C-reactive Protein was 1.29 vs 1.25 mg/dl, p < .001 for all). The findings were very similar when the analysis was conducted separately for flavonoids or phenolic acids, the two main classes of polyphenols consumed in this population.

CONCLUSIONS

Polyphenol intake is associated with a more favorable cardiovascular risk factors profile, independent of major confounders. These findings support the consumption of foods and beverages rich in different classes of polyphenols particularly in people with diabetes.

CLINICAL TRIAL

http://www.clinicaltrials.gov; Study ID number: NCT00700856.

Circulating vitamin D in relation to cancer incidence and survival of the head and neck and oesophagus in the EPIC cohort

Experimental and epidemiological data suggest that vitamin D play a role in pathogenesis and progression of cancer, but prospective data on head and neck cancer (HNC) and oesophagus cancer are limited. The European Prospective Investigation into Cancer and Nutrition (EPIC) study recruited 385,747 participants with blood samples between 1992 and 2000. This analysis includes 497 case-control pairs of the head and neck and oesophagus, as well as 443 additional controls. Circulating 25(OH)D3 were measured in pre-diagnostic samples and evaluated in relation to HNC and oesophagus cancer risk and post-diagnosis all-cause mortality. After controlling for risk factors, a doubling of 25(OH)D3 was associated with 30% lower odds of HNC (OR 0.70, 95% confidence interval [95% CI] 0.56-0.88, Ptrend = 0.001). Subsequent analyses by anatomical sub-site indicated clear inverse associations with risk of larynx and hypopharynx cancer combined (OR 0.55, 95CI% 0.39-0.78) and oral cavity cancer (OR 0.60, 95CI% 0.42-0.87). Low 25(OH)D3 concentrations were also associated with higher risk of death from any cause among HNC cases. No clear association was seen with risk or survival for oesophageal cancer. Study participants with elevated circulating concentrations of 25(OH)D3 had decreased risk of HNC, as well as improved survival following diagnosis.

Association Between Low-Density Lipoprotein Cholesterol-Lowering Genetic Variants and Risk of Type 2 Diabetes: A Meta-analysis

Importance

Low-density lipoprotein cholesterol (LDL-C)-lowering alleles in or near NPC1L1 or HMGCR, encoding the respective molecular targets of ezetimibe and statins, have previously been used as proxies to study the efficacy of these lipid-lowering drugs. Alleles near HMGCR are associated with a higher risk of type 2 diabetes, similar to the increased incidence of new-onset diabetes associated with statin treatment in randomized clinical trials. It is unknown whether alleles near NPC1L1 are associated with the risk of type 2 diabetes.

Objective

To investigate whether LDL-C-lowering alleles in or near NPC1L1 and other genes encoding current or prospective molecular targets of lipid-lowering therapy (ie, HMGCR, PCSK9, ABCG5/G8, LDLR) are associated with the risk of type 2 diabetes.

Design, Setting, and Participants

The associations with type 2 diabetes and coronary artery disease of LDL-C-lowering genetic variants were investigated in meta-analyses of genetic association studies. Meta-analyses included 50 775 individuals with type 2 diabetes and 270 269 controls and 60 801 individuals with coronary artery disease and 123 504 controls. Data collection took place in Europe and the United States between 1991 and 2016.

Exposures

Low-density lipoprotein cholesterol-lowering alleles in or near NPC1L1, HMGCR, PCSK9, ABCG5/G8, and LDLR.

Main Outcomes and Measures

Odds ratios (ORs) for type 2 diabetes and coronary artery disease.

Results

Low-density lipoprotein cholesterol-lowering genetic variants at NPC1L1 were inversely associated with coronary artery disease (OR for a genetically predicted 1-mmol/L [38.7-mg/dL] reduction in LDL-C of 0.61 [95% CI, 0.42-0.88]; P = .008) and directly associated with type 2 diabetes (OR for a genetically predicted 1-mmol/L reduction in LDL-C of 2.42 [95% CI, 1.70-3.43]; P < .001). For PCSK9 genetic variants, the OR for type 2 diabetes per 1-mmol/L genetically predicted reduction in LDL-C was 1.19 (95% CI, 1.02-1.38; P = .03). For a given reduction in LDL-C, genetic variants were associated with a similar reduction in coronary artery disease risk (I2 = 0% for heterogeneity in genetic associations; P = .93). However, associations with type 2 diabetes were heterogeneous (I2 = 77.2%; P = .002), indicating gene-specific associations with metabolic risk of LDL-C-lowering alleles.

Conclusions and Relevance

In this meta-analysis, exposure to LDL-C-lowering genetic variants in or near NPC1L1 and other genes was associated with a higher risk of type 2 diabetes. These data provide insights into potential adverse effects of LDL-C-lowering therapy.

Sex differences in food choices, adherence to dietary recommendations and plasma lipid profile in type 2 diabetes - The TOSCA.IT study

BACKGROUND AND AIMS

Diabetic women have a more adverse plasma lipid profile than men. Sex differences in dietary habits may play a role, but are little investigated. The study evaluates the quality of diet, adherence to the nutritional recommendations of the Diabetes and Nutrition Study Group and their relation with plasma lipid in men and women with diabetes.

METHODS AND RESULTS

We studied 2573 people, aged 50-75, enrolled in the TOSCA.IT study (clinicaltrials.gov; NCT00700856). Plasma lipids were measured centrally. Diet was assessed with a semi-quantitative food frequency questionnaire. Women had a more adverse plasma lipid profile than men. Women consumed significantly more legumes, vegetables, fruits, eggs, milk, vegetable oils, and added sugar, whereas men consumed more starchy foods, soft drinks and alcoholic beverages. This stands for a higher proportion (%) of energy intake from saturated fat and added sugar (12.0 ± 2.4 vs 11.5 ± 2.5 and 3.4 ± 3.2 vs 2.3 ± 3.2, P < 0.04), and a higher intake of fiber (11.2 ± 2.8 vs 10.4 ± 2.6 g/1000 Kcal/day) in women. Adherence to the recommendations for saturated fat and fiber consumption was associated with significantly lower LDL-cholesterol regardless of sex. Adherence to the recommendations for added sugars was associated with significantly lower triglycerides and higher HDL-cholesterol in men and women.

CONCLUSIONS

Men and women with diabetes show significant differences in adherence to nutritional recommendations, but sex differences in plasma lipid profile are unlikely to be explained by nutritional factors. Adherence to the nutritional recommendations is associated with a better plasma lipid profile regardless of sex, thus reinforcing the importance of substituting saturated for unsaturated fat sources, increasing fiber and reducing added sugar intake.

Are 6-8 year old Italian children moving away from the Mediterranean diet?

BACKGROUND

The Mediterranean diet (MD) is considered one of the healthiest dietary models, as it decreases the risk of chronic diseases and may modulate the organism's early response to environmental pollution. In recent decades, Mediterranean countries have been replacing their traditional diet with other less healthy eating habits, especially among children and teenagers.

OBJECTIVE

The aim of this study was to evaluate the MD and the level of adherence to it in 6-8 year old Italian children, in relation to residence, lifestyle, and social and family contexts.

METHODS

A questionnaire was administered to the children's parents in two seasons in 5 Italian towns. The diet section contained 116 questions investigating the frequency of consumption of different types of food. The Italian Mediterranean Index (IMI) was calculated according to the intake of 6 typical Mediterranean and 4 non-Mediterranean foods. On the basis of IMI score, MD adherence was classified as low (≤ 3 IMI score), medium (4-5) and high (≥ 6). Total energy load and diet composition in micro- and macronutrients were calculated from consumption frequency.

RESULTS

Diet analysis was computed on 1164 subjects with two complete questionnaires. Body mass index, calculated for each subject, showed that 28.9% of the children were overweight, the figure varying slightly with area of residence. Our findings showed that 59.0% of the children had a low score for MD adherence.

CONCLUSIONS

The results of this study showed that most Italian children did not follow the MD and socio-economic characteristics appeared not to be associated with type of diet.

Urinary excretions of 34 dietary polyphenols and their associations with lifestyle factors in the EPIC cohort study

Urinary excretion of 34 dietary polyphenols and their variations according to diet and other lifestyle factors were measured by tandem mass spectrometry in 475 adult participants from the European Prospective Investigation into Cancer and Nutrition (EPIC) cross-sectional study. A single 24-hour urine sample was analysed for each subject from 4 European countries. The highest median levels were observed for phenolic acids such as 4-hydroxyphenylacetic acid (157 μmol/24 h), followed by 3-hydroxyphenylacetic, ferulic, vanillic and homovanillic acids (20-50 μmol/24 h). The lowest concentrations were observed for equol, apigenin and resveratrol (<0.1 μmol/24 h). Urinary polyphenols significantly varied by centre, followed by alcohol intake, sex, educational level, and energy intake. This variability is largely explained by geographical variations in the diet, as suggested by the high correlations (r > 0.5) observed between urinary polyphenols and the intake of their main food sources (e.g., resveratrol and gallic acid ethyl ester with red wine intake; caffeic, protocatechuic and ferulic acids with coffee consumption; and hesperetin and naringenin with citrus fruit intake). The large variations in urinary polyphenols observed are largely determined by food preferences. These polyphenol biomarkers should allow more accurate evaluation of the relationships between polyphenol exposure and the risk of chronic diseases in large epidemiological studies.

Combined effects of smoking and HPV16 in oropharyngeal cancer

BACKGROUND

Although smoking and HPV infection are recognized as important risk factors for oropharyngeal cancer, how their joint exposure impacts on oropharyngeal cancer risk is unclear. Specifically, whether smoking confers any additional risk to HPV-positive oropharyngeal cancer is not understood.

METHODS

Using HPV serology as a marker of HPV-related cancer, we examined the interaction between smoking and HPV16 in 459 oropharyngeal (and 1445 oral cavity and laryngeal) cancer patients and 3024 control participants from two large European multi-centre studies. Odds ratios and credible intervals [CrI], adjusted for potential confounders, were estimated using Bayesian logistic regression.

RESULTS

Both smoking [odds ratio (OR [CrI]: 6.82 [4.52, 10.29]) and HPV seropositivity (OR [CrI]: 235.69 [99.95, 555.74]) were independently associated with oropharyngeal cancer. The joint association of smoking and HPV seropositivity was consistent with that expected on the additive scale (synergy index [CrI]: 1.32 [0.51, 3.45]), suggesting they act as independent risk factors for oropharyngeal cancer.

CONCLUSIONS

Smoking was consistently associated with increase in oropharyngeal cancer risk in models stratified by HPV16 seropositivity. In addition, we report that the prevalence of oropharyngeal cancer increases with smoking for both HPV16-positive and HPV16-negative persons. The impact of smoking on HPV16-positive oropharyngeal cancer highlights the continued need for smoking cessation programmes for primary prevention of head and neck cancer.

A genomic approach to therapeutic target validation identifies a glucose-lowering GLP1R variant protective for coronary heart disease

Regulatory authorities have indicated that new drugs to treat type 2 diabetes (T2D) should not be associated with an unacceptable increase in cardiovascular risk. Human genetics may be able to guide development of antidiabetic therapies by predicting cardiovascular and other health endpoints. We therefore investigated the association of variants in six genes that encode drug targets for obesity or T2D with a range of metabolic traits in up to 11,806 individuals by targeted exome sequencing and follow-up in 39,979 individuals by targeted genotyping, with additional in silico follow-up in consortia. We used these data to first compare associations of variants in genes encoding drug targets with the effects of pharmacological manipulation of those targets in clinical trials. We then tested the association of those variants with disease outcomes, including coronary heart disease, to predict cardiovascular safety of these agents. A low-frequency missense variant (Ala316Thr; rs10305492) in the gene encoding glucagon-like peptide-1 receptor (GLP1R), the target of GLP1R agonists, was associated with lower fasting glucose and T2D risk, consistent with GLP1R agonist therapies. The minor allele was also associated with protection against heart disease, thus providing evidence that GLP1R agonists are not likely to be associated with an unacceptable increase in cardiovascular risk. Our results provide an encouraging signal that these agents may be associated with benefit, a question currently being addressed in randomized controlled trials. Genetic variants associated with metabolic traits and multiple disease outcomes can be used to validate therapeutic targets at an early stage in the drug development process.

Plasma Riboflavin and Vitamin B-6, but Not Homocysteine, Folate, or Vitamin B-12, Are Inversely Associated with Breast Cancer Risk in the European Prospective Investigation into Cancer and Nutrition-Varese Cohort

BACKGROUND

One-carbon metabolism-important for DNA stability and integrity-may play a role in breast carcinogenesis. However, epidemiologic studies addressing this issue have yielded inconsistent results.

OBJECTIVE

We prospectively investigated associations between breast cancer and plasma folate, riboflavin, vitamin B-6, vitamin B-12, and homocysteine in women recruited to the Varese (Italy) cohort of the EPIC (European Prospective Investigation into Cancer and Nutrition) study.

METHODS

We performed a nested case-control study on women aged 35-65 y at recruitment with a median body mass index of 25.3 kg/m(2) who gave blood samples in 1987-1992 and again in 1993-1998. Breast cancer cases identified by 31 December 2009 were individually matched to controls. RRs of breast cancer (and subtypes defined by hormone receptor status) with 95% CIs were estimated by unconditional logistic regression, controlling for matching factors and breast cancer risk factors.

RESULTS

After a median of 14.9 y, 276 breast cancer cases were identified and matched to 276 controls. Increasing plasma vitamin B-6 was associated with decreased risk of overall (RR: 0.78; 95% CI: 0.63, 0.96 for 1-SD increase), premenopausal (RR: 0.66; 95% CI: 0.48, 0.92 for 1-SD increase), estrogen receptor-positive (RR: 0.79; 95% CI: 0.63, 1.00 for 1-SD increase), and progesterone receptor-positive (RR: 0.72; 95% CI: 0.55, 0.95 for 1-SD increase) breast cancers. Increased plasma vitamin B-6 was also associated with decreased breast cancer risk in alcohol consumers (≥7 g/d) compared with consumption of <7 g/d or nonconsumption (RR: 0.71; 95% CI: 0.51, 0.99). High plasma riboflavin was associated with significantly lower risk in premenopausal women (RR: 0.45; 95% CI: 0.21, 0.94; highest compared with the lowest quartile, P trend = 0.021). Plasma homocysteine, folate, and vitamin B-12 were not associated with breast cancer risk.

CONCLUSIONS

High plasma vitamin B-6 and riboflavin may lower breast cancer risk, especially in premenopausal women. Additional research is necessary to further explore these associations.

Evaluation of a Modified Italian European Prospective Investigation into Cancer and Nutrition Food Frequency Questionnaire for Individuals with Celiac Disease

BACKGROUND

To date, it is unclear whether individuals with celiac disease following a gluten-free (GF) diet for several years have adequate intake of all recommended nutrients. Lack of a food frequency questionnaire (FFQ) for individuals with celiac disease could be partly responsible for this still-debated issue.

OBJECTIVE

The aim of the study is to evaluate the performance of a modified European Prospective Investigation into Cancer and Nutrition (EPIC) FFQ in estimating nutrient and food intake in a celiac population.

DESIGN

In a cross-sectional study, the dietary habits of individuals with celiac disease were reported using a modified Italian EPIC FFQ and were compared to a 7-day weighed food record as a reference method.

PARTICIPANTS/SETTING

A total of 200 individuals with histologically confirmed celiac disease were enrolled in the study between October 2012 and August 2014 at the Center for Prevention and Diagnosis of Celiac Disease (Milan, Italy).

MAIN OUTCOME MEASURES

Nutrient and food category intake were calculated by 7-day weighed food record using an Italian food database integrated with the nutrient composition of 60 GF foods and the modified EPIC FFQ, in which 24 foods were substituted with GF foods comparable for energy and carbohydrate content.

STATISTICAL ANALYSES PERFORMED

An evaluation of the modified FFQ compared to 7-day weighed food record in assessing the reported intake of nutrient and food groups was conducted using Spearman's correlation coefficients and weighted κ.

RESULTS

One hundred individuals completed the study. The Spearman's correlation coefficients of FFQ and 7-day weighed food record ranged from .13 to .73 for nutrients and from .23 to .75 for food groups. A moderate agreement, which was defined as a weighted κ value of .40 to .60, was obtained for 30% of the analyzed nutrients, and 40% of the nutrients showed values between .30 and .40. The weighted κ exceeded .40 for 60% of the 15 analyzed food groups.

CONCLUSIONS

The modified EPIC FFQ demonstrated moderate congruence with a weighed food record in ranking individuals by dietary intakes, particularly food groups.

Association of Multiple Biomarkers of Iron Metabolism and Type 2 Diabetes: The EPIC-InterAct Study

OBJECTIVE

Observational studies show an association between ferritin and type 2 diabetes (T2D), suggesting a role of high iron stores in T2D development. However, ferritin is influenced by factors other than iron stores, which is less the case for other biomarkers of iron metabolism. We investigated associations of ferritin, transferrin saturation (TSAT), serum iron, and transferrin with T2D incidence to clarify the role of iron in the pathogenesis of T2D.

RESEARCH DESIGN AND METHODS

The European Prospective Investigation into Cancer and Nutrition-InterAct study includes 12,403 incident T2D cases and a representative subcohort of 16,154 individuals from a European cohort with 3.99 million person-years of follow-up. We studied the prospective association of ferritin, TSAT, serum iron, and transferrin with incident T2D in 11,052 cases and a random subcohort of 15,182 individuals and assessed whether these associations differed by subgroups of the population.

RESULTS

Higher levels of ferritin and transferrin were associated with a higher risk of T2D (hazard ratio [HR] [95% CI] in men and women, respectively: 1.07 [1.01-1.12] and 1.12 [1.05-1.19] per 100 μg/L higher ferritin level; 1.11 [1.00-1.24] and 1.22 [1.12-1.33] per 0.5 g/L higher transferrin level) after adjustment for age, center, BMI, physical activity, smoking status, education, hs-CRP, alanine aminotransferase, and γ-glutamyl transferase. Elevated TSAT (≥45% vs. <45%) was associated with a lower risk of T2D in women (0.68 [0.54-0.86]) but was not statistically significantly associated in men (0.90 [0.75-1.08]). Serum iron was not associated with T2D. The association of ferritin with T2D was stronger among leaner individuals (Pinteraction < 0.01).

CONCLUSIONS

The pattern of association of TSAT and transferrin with T2D suggests that the underlying relationship between iron stores and T2D is more complex than the simple link suggested by the association of ferritin with T2D.

Prospective association of liver function biomarkers with development of hepatobiliary cancers

INTRODUCTION

Serum liver biomarkers (gamma-glutamyl transferase, GGT; alanine aminotransferase, ALT; aspartate aminotransferase, AST; alkaline phosphatase, ALP; total bilirubin) are used as indicators of liver disease, but there is currently little data on their prospective association with risk of hepatobiliary cancers.

METHODS

A nested-case control study was conducted within the prospective EPIC cohort (>520,000 participants, 10 European countries). After a mean 7.5 mean years of follow-up, 121 hepatocellular carcinoma (HCC), 34 intrahepatic bile duct (IHBC) and 131 gallbladder and biliary tract (GBTC) cases were identified and matched to 2 controls each. Circulating biomarkers were measured in serum taken at recruitment into the cohort, prior to cancer diagnosis. Multivariable adjusted conditional logistic regression was used to calculate odds ratios and 95% confidence intervals (OR; 95%CI).

RESULTS

In multivariable models, 1SD increase of each log-transformed biomarker was positively associated with HCC risk (OR(GGT)=4.23, 95%CI:2.72-6.59; OR(ALP)=3.43, 95%CI:2.31-5.10;OR(AST)=3.00, 95%CI:2.04-4.42; OR(ALT)=2.69, 95%CI:1.89-3.84; OR(Bilirubin)=2.25, 95%CI:1.58-3.20). Each liver enzyme (OR(GGT)=4.98; 95%CI:1.75-14.17; OR(AST)=3.10, 95%CI:1.04-9.30; OR(ALT)=2.86, 95%CI:1.26-6.48, OR(ALP)=2.31, 95%CI:1.10-4.86) but not bilirubin (OR(Bilirubin)=1.46,95%CI:0.85-2.51) showed a significant association with IHBC. Only ALP was significantly associated with GBTC risk (OR(ALP)=1.59, 95%CI:1.20-2.09).

CONCLUSION

This study shows positive associations between circulating liver biomarkers in sera collected prior to cancer diagnoses and the risks of developing HCC or IHBC, but not GBTC.

Consumption of soft drinks and juices and risk of liver and biliary tract cancers in a European cohort

PURPOSE

The aim of the study was to assess associations between intake of combined soft drinks (sugar sweetened and artificially sweetened) and fruit and vegetable juices and the risk of hepatocellular carcinoma (HCC), intrahepatic bile duct (IHBC) and biliary tract cancers (GBTC) using data from the European Prospective Investigation into Cancer and Nutrition cohort of 477,206 participants from 10 European countries.

METHODS

After 11.4 years of follow-up, 191 HCC, 66 IHBC and 236 GBTC cases were identified. Hazard ratios and 95% confidence intervals (HR; 95% CI) were estimated with Cox regression models with multivariable adjustment (baseline total energy intake, alcohol consumption and intake pattern, body mass index, physical activity, level of educational attainment and self-reported diabetes status).

RESULTS

No risk associations were observed for IHBC or GBTC. Combined soft drinks consumption of >6 servings/week was positively associated with HCC risk: HR 1.83; 95% CI 1.11-3.02, p trend = 0.01 versus non-consumers. In sub-group analyses available for 91% of the cohort artificially sweetened soft drinks increased HCC risk by 6% per 1 serving increment (HR 1.06, 95% CI 1.03-1.09, n cases = 101); for sugar-sweetened soft drinks, this association was null (HR 1.00, 95% CI 0.95-1.06; n cases = 127, p heterogeneity = 0.07). Juice consumption was not associated with HCC risk, except at very low intakes (<1 serving/week: HR 0.60; 95% CI 0.38-0.95; p trend = 0.02 vs. non-consumers).

CONCLUSIONS

Daily intake of combined soft drinks is positively associated with HCC, but a differential association between sugar and artificially sweetened cannot be discounted. This study provides some insight into possible associations of HCC with sugary drinks intake. Further exploration in other settings is required.

The association of coffee intake with liver cancer risk is mediated by biomarkers of inflammation and hepatocellular injury: data from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Higher coffee intake has been purportedly related to a lower risk of liver cancer. However, it remains unclear whether this association may be accounted for by specific biological mechanisms.

OBJECTIVE

We aimed to evaluate the potential mediating roles of inflammatory, metabolic, liver injury, and iron metabolism biomarkers on the association between coffee intake and the primary form of liver cancer-hepatocellular carcinoma (HCC).

DESIGN

We conducted a prospective nested case-control study within the European Prospective Investigation into Cancer and Nutrition among 125 incident HCC cases matched to 250 controls using an incidence-density sampling procedure. The association of coffee intake with HCC risk was evaluated by using multivariable-adjusted conditional logistic regression that accounted for smoking, alcohol consumption, hepatitis infection, and other established liver cancer risk factors. The mediating effects of 21 biomarkers were evaluated on the basis of percentage changes and associated 95% CIs in the estimated regression coefficients of models with and without adjustment for biomarkers individually and in combination.

RESULTS

The multivariable-adjusted RR of having ≥4 cups (600 mL) coffee/d compared with <2 cups (300 mL)/d was 0.25 (95% CI: 0.11, 0.62; P-trend = 0.006). A statistically significant attenuation of the association between coffee intake and HCC risk and thereby suspected mediation was confirmed for the inflammatory biomarker IL-6 and for the biomarkers of hepatocellular injury glutamate dehydrogenase, alanine aminotransferase, aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and total bilirubin, which-in combination-attenuated the regression coefficients by 72% (95% CI: 7%, 239%). Of the investigated biomarkers, IL-6, AST, and GGT produced the highest change in the regression coefficients: 40%, 56%, and 60%, respectively.

CONCLUSION

These data suggest that the inverse association of coffee intake with HCC risk was partly accounted for by biomarkers of inflammation and hepatocellular injury.

Subtypes of fruit and vegetables, variety in consumption and risk of colon and rectal cancer in the European Prospective Investigation into Cancer and Nutrition

Previously, a lower risk of colorectal cancer was observed with fruit and vegetable consumption in the European Prospective Investigation into Cancer and Nutrition within a follow-up period of 9 years which was not fully supported by a recent meta-analysis. Therefore, we were interested in the relation with extended follow-up, also focusing on single subtypes and a variety of intake of fruit and vegetables. Fruit and vegetable consumption was assessed at baseline. After an average of 13 years of follow-up, 3,370 participants were diagnosed with colon or rectal cancer. Diet diversity scores were constructed to quantify variety in fruit and vegetable consumption. A lower risk of colon cancer was observed with higher self-reported consumption of fruit and vegetable combined (HR Q4 vs. Q1 0.87, 95% CI 0.75-1.01, p for trend 0.02), but no consistent association was observed for separate consumption of fruits and vegetables. No associations with risk of rectal cancer were observed. The few observed associations for some fruit and vegetable subtypes with colon cancer risk may have been due to chance. Variety in consumption of fruits and vegetables was not associated with a lower risk of colon or rectal cancer. Although a lower risk of colon cancer is suggested with high consumption of fruit and vegetables, this study does not support a clear inverse association between fruit and vegetable consumption and colon or rectal cancer beyond a follow-up of more than 10 years. Attenuation of the risk estimates from dietary changes over time cannot be excluded, but appears unlikely.

Dietary Total Antioxidant Capacity and Colorectal Cancer in the Italian EPIC Cohort

Background

Colorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed.

Methods

We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center.

Results

Four hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44–0.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19–3.66; 3rd tertile 2.48 95%CI: 1.32–4.66; P trend 0.007). Intakes of vitamin C, vitamin E, and ß-carotene were not significantly associated with colorectal cancer risk.

Conclusions

Further prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers.