S. Sieri

General and Abdominal Adiposity and Risk of Death in Europe

BACKGROUNDnPrevious studies have relied predominantly on the body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) to assess the association of adiposity with the risk of death, but few have examined whether the distribution of body fat contributes to the prediction of death.nnnMETHODSnWe examined the association of BMI, waist circumference, and waist-to-hip ratio with the risk of death among 359,387 participants from nine countries in the European Prospective Investigation into Cancer and Nutrition (EPIC). We used a Cox regression analysis, with age as the time variable, and stratified the models according to study center and age at recruitment, with further adjustment for educational level, smoking status, alcohol consumption, physical activity, and height.nnnRESULTSnDuring a mean follow-up of 9.7 years, 14,723 participants died. The lowest risks of death related to BMI were observed at a BMI of 25.3 for men and 24.3 for women. After adjustment for BMI, waist circumference and waist-to-hip ratio were strongly associated with the risk of death. Relative risks among men and women in the highest quintile of waist circumference were 2.05 (95% confidence interval [CI], 1.80 to 2.33) and 1.78 (95% CI, 1.56 to 2.04), respectively, and in the highest quintile of waist-to-hip ratio, the relative risks were 1.68 (95% CI, 1.53 to 1.84) and 1.51 (95% CI, 1.37 to 1.66), respectively. BMI remained significantly associated with the risk of death in models that included waist circumference or waist-to-hip ratio (P<0.001).nnnCONCLUSIONSnThese data suggest that both general adiposity and abdominal adiposity are associated with the risk of death and support the use of waist circumference or waist-to-hip ratio in addition to BMI in assessing the risk of death.

Plasma carotenoids as biomarkers of intake of fruits and vegetables: individual-level correlations in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Objective:The aim in this study was to assess the association between individual plasma carotenoid levels (α-carotene, β-carotene, lycopene, β-cryptoxanthin, lutein, zeaxanthin) and fruit and vegetable intakes recorded by a calibrated food questionnaire (FQ) and 24-h dietary recall records (24HDR) in nine different European countries with diverse populations and widely varying intakes of plant foods.Design:A stratified random subsample of 3089 men and women from nine countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), who had provided blood samples and dietary and other lifestyle information between 1992 and 2000, were included.Results:β-Cryptoxanthin was most strongly correlated with total fruits (FQ r=0.52, 24HDR r=0.39), lycopene with tomato and tomato products (FQ r=0.38, 24HDR r=0.25), and α-carotene with intake of root vegetables (r=0.39) and of total carrots (r=0.38) for FQ only. Based on diet measured by FQ and adjusting for possible confounding by body mass index (BMI), age, gender, smoking status, alcohol intake, and energy intake, the strongest predictors of individual plasma carotenoid levels were fruits (R partial 2=17.2%) for β-cryptoxanthin, total carrots (R partial 2=13.4%) and root vegetables (R partial 2=13.3%) for α-carotene, and tomato products (R partial 2=13.8%) for lycopene. For 24HDR, the highest R partial 2 was for fruits in relation to β-cryptoxanthin (7.9%).Conclusions:Intakes of specific fruits and vegetables as measured by food questionnaires are good predictors of certain individual plasma carotenoid levels in our multicentre European study. At individual subject levels, FQ measurements of fruits, root vegetables and carrots, and tomato products are, respectively, good predictors of β-cryptoxanthin, α-carotene, and lycopene in plasma.

Diet in the Italian EPIC cohorts: presentation of data and methodological issues.

One of the aims of the EPIC study is to produce accurate descriptions of the dietary habits of the participants recruited in the 27 EPIC centers of 10 European countries. To do this, different dietary assessment instruments were developed and applied to capture the wide range of diets characterizing the different European populations. Three different food frequency questionnaires were developed for Italy: one for the centers of Varese, Turin and Florence, one for Ragusa and one for Naples. These inquired about eating habits over the previous year and were completed by 46,839 Italian EPIC participants. Specially developed software analyzed the responses and linked them to food composition tables in order to provide a nutritional breakdown of individual and collective diets. A further aim of EPIC was to develop a method of rendering data from different dietary questionnaires comparable. To do this, dietary data were collected from a sample of about 8% of the Italian EPIC cohort, using a standardized computer-driven 24-hour dietary recall interview, and then compared with the dietary data collected by the questionnaires. This paper provides an extensive description of the technical features and performance of the food frequency questionnaires and the 24-hour recall interview, including a comparison of estimates of the intake of different food groups provided by the two instruments. From this comparison, the repeatability and reliability of consumption estimates was assessed, resulting in indications for improving data comparability. The paper also presents food frequency questionnaire estimates of the daily intake of foods and nutrients by center, sex and age group, as well as information on dietary habits such as place and time of intake, and food preparation and preservation methods as provided by the 24-hour recall interview. The picture that emerged is that Italian eating habits are undergoing marked changes, with a tendency to less healthy eating. Documentation of these changes in relation to age, sex and region provides an essential starting point for investigating the influence of diet on the development of cancer and other chronic diseases.

Sex hormones and risk of breast cancer in premenopausal women: a collaborative reanalysis of individual participant data from seven prospective studies

BACKGROUNDnAssociations between circulating concentrations of oestrogens, progesterone, and androgens with breast cancer and related risk factors in premenopausal women are not well understood. We aimed to characterise these associations with a pooled analysis of data from seven studies.nnnMETHODSnIndividual participant data for prediagnostic sex hormone and sex hormone-binding globulin (SHBG) concentrations were contributed from seven prospective studies. We restricted analyses to women who were premenopausal and younger than 50 years at blood collection, and to women with breast cancer diagnosed before age 50 years. We estimated odds ratios (ORs) with 95% CIs for breast cancer associated with hormone concentrations by conditional logistic regression in cases and controls matched for age, date of blood collection, and day of cycle, with stratification by study and further adjustment for cycle phase. We examined associations of hormones with risk factors for breast cancer in control women by comparing geometric mean hormone concentrations in categories of these risk factors, adjusted for study, age, phase of menstrual cycle, and body-mass index (BMI). All statistical tests were two-sided.nnnFINDINGSnWe included data for up to 767 women with breast cancer and 1699 controls in the risk analyses. Breast cancer risk was associated with a doubling in concentrations of oestradiol (OR 1·19, 95% CI 1·06-1·35), calculated free oestradiol (1·17, 1·03-1·33), oestrone (1·27, 1·05-1·54), androstenedione (1·30, 1·10-1·55), dehydroepiandrosterone sulphate (1·17, 1·04-1·32), testosterone (1·18, 1·03-1·35), and calculated free testosterone (1·08, 0·97-1·21). Breast cancer risk was not associated with luteal phase progesterone (doubling in concentration OR 1·00, 95% CI 0·92-1·09), and adjustment for other factors had little effect on any of these ORs. Cross-sectional analyses in control women showed several associations of sex hormones with breast cancer risk factors.nnnINTERPRETATIONnCirculating oestrogens and androgens are positively associated with the risk for breast cancer in premenopausal women.

Diet, serum insulin-like growth factor-I and IGF-binding protein-3 in European women

Objective:The aim of this study was to examine the relationship of diet with serum insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 in women.Design:Cross-sectional study.Setting and subjects:The population are 2109 women who were control subjects in a case–control study of breast cancer nested in the European Prospective Investigation into Cancer and Nutrition. Control subjects were randomly chosen among risk sets consisting of female cohort members alive and free of cancer (except non-melanoma skin cancer) at the time of diagnosis of the index case. Matching criteria were age at enrolment, follow-up time, time of the day of blood collection and study centre. Diet was measured through validated questionnaires. Serum hormone concentrations were measured by enzyme-linked immunosorbent assays. The relationship between serum IGF-I, IGFBP-3, and intake of nutrients and foods was explored by linear regression in models adjusted for energy intake, age, body mass index, smoking, physical activity, centre and laboratory batch.Results:Serum IGF-I levels were positively related to protein intake (P trend<0.001), but not related to energy, fat or carbohydrate intake. Positive relationships were observed with the intake of milk (P trend=0.007), calcium (P trend<0.001), magnesium (P trend=0.003), phosphorus (P trend<0.001), potassium (P trend=0.002), vitamin B6 (P trend=0.03), vitamin B2 (P trend=0.001) and inverse relationships with vegetables (P trend=0.02) and beta-carotene (P trend=0.02). IGFBP-3 was not related with most of the nutrients and foods in this study.Conclusions:In this population, circulating IGF-I is modestly related with the intake of protein and minerals, and with milk and cheese, while IGFBP-3 does not appear to be related with diet.

A molecular epidemiology project on diet and cancer: The EPIC-Italy prospective study. Design and baseline characteristics of participants

EPIC-Italy is the Italian section of a larger project known as EPIC (European Prospective Investigation into Cancer and Nutrition), a prospective study on diet and cancer carried out in 10 European countries. In the period 1993-1998, EPIC-Italy completed the recruitment of 47,749 volunteers (15,171 men, 32,578 women, aged 35-65 years) in 4 different areas covered by cancer registries: Varese (12,083 volunteers) and Turin (10,604) in the Northern part of the country; Florence (13,597) and Ragusa (6,403) in Central and Southern Italy, respectively. An associate center in Naples enrolled 5,062 women. Detailed information for each individual volunteer about diet and life-style habits, anthropometric measurements and a blood sample was collected, after signing an informed consent form. A food frequency questionnaire specifically developed for the Italian dietary pattern was tested in a pilot phase. A computerized data base with the dietary and lifestyle information of each participant was completed. Blood samples were processed in the same day of collection, aliquoted (RBC, WBC, serum and plasma) and stored in liquid nitrogen containers. Follow-up procedures were validated and implemented for the identification of newly diagnosed cancer cases. Cancer incidence was related to dietary habits and biochemical markers of food consumption and individual susceptibility in order to test the role of diet-related exposure in the etiology of cancer and its interaction with other environmental or genetic determinants. The comparability of information in a prospective study design is much higher than in other studies. The availability of such a large biological bank linked to individual data on dietary and life-style exposures also provides the unique opportunity of evaluating the role of selected genotypes involved in the metabolism of chemical compounds and DNA repair, potentially related to the risk of cancer, in residents of geographic areas of Italy characterized by specific cancer risk and different dietary patterns. Baseline characteristics of participants are briefly described.

Effects of dietary intervention on IGF-I and IGF-binding proteins, and related alterations in sex steroid metabolism: the Diet and Androgens (DIANA) Randomised Trial

Objective: To assess the effects of a comprehensive change in dietary composition on endogenous hormone metabolism. The specific aim was to examine whether this intervention could lead to favourable changes in insulin sensitivity, levels of IGF-I and IGF-binding proteins (IGFBPs), and total and bioavailable testosterone and estradiol, that would be expected to reduce breast cancer risk.Design: Randomised dietary intervention study; duration of 5 months.Subjects: From a total of 99 postmenopausal women, who had elevated baseline plasma testosterone levels, 49 women were randomly assigned to the dietary intervention arm and the other 50 to a control group.Interventions: Main aspects of the dietary intervention were reductions in the intake of total fat and refined carbohydrates, an increase in the ratio of n-3 over n-6 plus saturated fatty acids, and increased intakes of foods rich in dietary fibre and phytooestrogens.Results: Relative to the control group, women of the intervention group showed a significant reduction of body weight, waist circumference, fasting serum levels of testosterone, C peptide, glucose, and insulin area after glucose tolerance test, and a significant increase of serum levels of sex hormone-binding globulin, IGFBP-1, -2, and growth hormone-binding protein. Serum levels of IGF-I did not change.Conclusions: This comprehensive dietary intervention strategy proved to be successful in inducing changes in endogenous hormone metabolism that might eventually result in reduced breast cancer risk. Additional studies are needed to show whether the dietary intervention and related hormonal changes can be both maintained over longer periods, of at least several years.

Body mass index, waist circumference and waist-hip ratio and serum levels of IGF-I and IGFBP-3 in European women

Objective:To examine the relationship between body mass index (BMI) and waist–hip ratio (WHR) with serum levels of insulin-like growth factor-I (IGF-I), and its binding protein (IGFBP)-3.Design:Cross-sectional study on 2139 women participating in a case–control study on breast cancer and endogenous hormones. Data on lifestyle and reproductive factors were collected by means of questionnaires. Body height, weight, waist and hip circumferences were measured. Serum levels of IGF-I and insulin-like binding protein (IGFBP)-3 were measured by enzyme-linked immunosorbent assays. Adjusted mean levels of IGF-I and IGFBP-3 across quintiles of BMI, waist circumference, and WHR were calculated by linear regression. Results were adjusted for potential confounders associated with IGF-I and IGFBP-3.Results:Adjusted mean serum IGF-I values were lower in women with BMI<22.5u2009kg/m2 or BMI>29.2u2009kg/m2 compared to women with BMI within this range (Pheterogeneity<0.0001, Ptrend=0.35). Insulin-like growth factor-I was not related to WHR after adjustment for BMI. IGF-binding protein-3 was linearly positively related to waist and WHR after mutual adjustment. The molar ratio IGF-I/IGFBP-3 had a non-linear relation with BMI and a linear inverse relationship with WHR (P trend=0.005).Conclusions:Our data confirm the nonlinear relationship of circulating IGF-I to total adiposity in women. Serum IGFBP-3 was positively related to central adiposity. These suggest that bioavailable IGF-I levels could be lower in obese compared to non-obese women and inversely related to central adiposity.

Dietary intakes and food sources of phytoestrogens in the European Prospective Investigation into Cancer and Nutrition (EPIC) 24-hour dietary recall cohort

BACKGROUND/OBJECTIVES:Phytoestrogens are estradiol-like natural compounds found in plants that have been associated with protective effects against chronic diseases, including some cancers, cardiovascular diseases and osteoporosis. The purpose of this study was to estimate the dietary intake of phytoestrogens, identify their food sources and their association with lifestyle factors in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.SUBJECTS/METHODS:Single 24-hour dietary recalls were collected from 36u2009037 individuals from 10 European countries, aged 35–74 years using a standardized computerized interview programe (EPIC-Soft). An ad hoc food composition database on phytoestrogens (isoflavones, lignans, coumestans, enterolignans and equol) was compiled using data from available databases, in order to obtain and describe phytoestrogen intakes and their food sources across 27 redefined EPIC centres.RESULTS:Mean total phytoestrogen intake was the highest in the UK health-conscious group (24.9u2009mg/day in men and 21.1u2009mg/day in women) whereas lowest in Greece (1.3u2009mg/day) in men and Spain-Granada (1.0u2009mg/day) in women. Northern European countries had higher intakes than southern countries. The main phytoestrogen contributors were isoflavones in both UK centres and lignans in the other EPIC cohorts. Age, body mass index, educational level, smoking status and physical activity were related to increased intakes of lignans, enterolignans and equol, but not to total phytoestrogen, isoflavone or coumestan intakes. In the UK cohorts, the major food sources of phytoestrogens were soy products. In the other EPIC cohorts the dietary sources were more distributed, among fruits, vegetables, soy products, cereal products, non-alcoholic and alcoholic beverages.CONCLUSIONS:There was a high variability in the dietary intake of total and phytoestrogen subclasses and their food sources across European regions.

Fruits and vegetables consumption and the risk of histological subtypes of lung cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)

ObjectiveTo examine the association between fruit and vegetable consumption and risk of different histological subtypes of lung cancer among participants of the European Prospective Investigation into Cancer and Nutrition study.MethodsMultivariable Cox proportional hazard models were used to analyze the data. A calibration study in a subsample was used to reduce dietary measurement errors.ResultsDuring a mean follow-up of 8.7xa0years, 1,830 incident cases of lung cancer (574 adenocarcinoma, 286 small cell, 137 large cell, 363 squamous cell, 470 other histologies) were identified. In line with our previous conclusions, we found that after calibration a 100xa0g/day increase in fruit and vegetables consumption was associated with a reduced lung cancer risk (HR 0.94; 95% CI 0.89–0.99). This was also seen among current smokers (HR 0.93; 95% CI 0.90–0.97). Risks of squamous cell carcinomas in current smokers were reduced for an increase of 100xa0g/day of fruit and vegetables combined (HR 0.85; 95% CI 0.76–0.94), while no clear effects were seen for the other histological subtypes.ConclusionWe observed inverse associations between the consumption of vegetables and fruits and risk of lung cancer without a clear effect on specific histological subtypes of lung cancer. In current smokers, consumption of vegetables and fruits may reduce lung cancer risk, in particular the risk of squamous cell carcinomas.