Biomedical subjects

Sabina Sieri

Publications and source records attributed to Sabina Sieri.

28 records · Page 2Linked to original sources

PubMed2004

Dietary patterns and risk of breast cancer in the ORDET cohort.

The aim of this study was to evaluate the association between dietary patterns and risk of developing breast cancer in an Italian cohort. Women volunteers were recruited from 1987 to 1992 from residents in Varese province, northern Italy, an area covered by a cancer registry. Participants completed a semiquantitative food frequency questionnaire, and anthropometric and other data were collected systematically. Using nutritional data from 8984 women with an average follow up of 9.5 years and 207 incident cases of breast cancer, we conducted an exploratory factor analysis to identify major dietary patterns. Four dietary patterns, which explained 30% of the variance, emerged: salad vegetables (mainly consisting of raw vegetables and olive oil); western (mainly consisting of potatoes, red meat, eggs and butter); canteen (pasta and tomato sauce); and prudent (cooked vegetables, pulses, and fish, with negative loading on wines and spirits). After adjustment for potential confounders, only the salad vegetables pattern was associated with significantly lower (34-35%) breast cancer incidence (RR = 0.66, CI(95%) = 0.47+/-0.95 comparing highest with lowest tertile) with a significant linear trend (P = 0.016). Women with body mass index <25 had an even greater risk reduction in the highest tertile of the salad vegetables pattern (>50% less risk than the lowest tertile, RR = 0.39, CI(95%) = 0.22-0.69) with a significant trend (P = 0.001); whereas women with body mass index > or =25 had no protective effect for the consumption of salad vegetables. These findings suggest that a diet rich in raw vegetables and olive oil protects against breast cancer.

Adult↗

PubMed2003

Group level validation of protein intakes estimated by 24-hour diet recall and dietary questionnaires against 24-hour urinary nitrogen in the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study.

A calibration approach was developed to correct for systematic between-cohort dietary measurement errors in the European Prospective Investigation into Cancer and Nutrition (EPIC), a large multicenter cohort study. To validate the 24-h diet recalls (24-HDRs) as reference measurements for between-cohort calibration, we estimated the agreement between center mean nitrogen (N) and total energy intakes and mean 24-h urinary N. Similar analyses using N and energy intake data from different dietary questionnaires (DQs) used at study baseline were conducted to estimate the effect of the calibration approach. This study was conducted between 1995 and 1999, and involved 1103 volunteers of both genders from 12 centers participating in European Prospective Investigation into Cancer and Nutrition. Pearson's correlation coefficients were weighted for study center sample size. When both genders were considered together (n = 22), the correlation coefficients between the center mean log-transformed urinary estimates and the center mean log-transformed dietary N estimates from the 24-HDRs were 0.86 and 0.94 after exclusion of outliers. The corresponding correlation with the DQs was 0.53. When center mean total energy intakes were regressed on center mean urinary N, the correlation remained slightly higher with 24-HDRs (0.91; 0.95 after exclusion of outliers) than DQs (0.86). When stratified by gender, these correlations were systematically higher in men than women with both dietary methods. The beta regression coefficients were not significantly different from 1 when mean N (or total energy intakes) from 24-HDR or DQ were regressed on urinary estimates, except with N from 24-HDRs in men and, in most cases, after adjustment for age, body mass index, and sex with both genders together. This suggests that overall the systematic bias across centers is of uniform magnitude. Although relatively high correlations were observed between urinary N and both dietary methods in men, the errors in DQs tend to vary in both directions (under- and over-reporting) in contrast with 24-HDRs in women. This observation may have implications on the dietary measurement error characteristics and support the potential benefit of between-cohort calibration.

Calibration↗

PubMed2003

Toenail selenium as biomarker: reproducibility over a one-year period and factors influencing reproducibility.

We assessed the reproducibility of selenium levels in toenails, comparing concentrations in two sets of specimens collected about a year apart, from 80 women (40 pre-menopausal and 40 post-menopausal) in the period October 1990 to February 1992. The women were participants in a prospective study on hormones and diet in relation to prediagnostic breast cancer (the ORDET study) conducted in northern Italy. Toenail selenium was determined by electrothermal atomic absorption spectrometry. The data were log-transformed as they were not normally distributed. To assess reproducibility Pearson correlation coefficients (r) for the two selenium determinations were calculated in pre- and post-menopausal women, according to smoking status and acetone treatment. A weighted kappa statistic (k) assessed inter-quintile agreement between the two sets of measures. Toenail selenium levels were highly reproducible (r = 0.57, p < 0.001), especially in pre-menopausal women (r = 0.66, p <0.001). Smoking lowered selenium levels (mean difference of 0.24 microg/g, p < 0.05 between smokers and non smokers) but did not significantly influence reproducibility. Acetone treatment to remove nail polish did not modify selenium levels but affected inter-quintile agreement, with moderate agreement (k = 0.58, p < 0.001) when acetone was used at both or neither samplings; and fair non significant agreement (k = 0.39, p = 0.06) when acetone was used at one sampling but not the other. As selenium levels in toenails are highly reproducible, notwithstanding variation in selenium levels in food and long-term changes in individuals' food choices, toenail selenium may be a useful biomarker of selenium exposure, particularly since toenail samples provide a measure of long-term exposure. However age, smoking status and acetone treatment are possible causes of misclassification.

Acetone↗

PubMed2002

Fat and protein intake and subsequent breast cancer risk in postmenopausal women.

The role of diet in the etiology of breast cancer has been extensively evaluated. Case-control studies generally support an association, while cohort studies have produced inconsistent results. This study, carried out on the ORDET cohort, is the first prospective Italian study to address the relation between diet and breast cancer. Female volunteers were recruited from 1987 to 1992 among residents of Varese Province, Northern Italy, an area covered by a cancer registry. A semiquantitative self-administered food questionnaire was completed by participants. After a mean 5.5 yr of follow-up, 56 cases of invasive breast cancer were identified among the 3,367 postmenopausal members; 214 controls were randomly chosen from the cohort, matched to cases for age, menopausal status at recruitment, recruitment center, and recruitment period. The adjusted odds ratios for the highest tertile of intake vs. the lowest were 3.47 [95% confidence interval (CI) = 1.43-8.44] for total fat, 3.78 (95% CI = 0.95-15.0) for animal protein, and 0.42 (95% CI = 0.18-0.95) for total carbohydrates. These findings indicate a significant positive association between total fat and animal protein and risk of breast cancer and an inverse association with carbohydrates and constitute new evidence for a role of diet in the etiology of breast cancer.

Adult↗

PubMed2002

Fasting glucose is a risk factor for breast cancer: a prospective study.

There is some evidence that glucose and other factors related to glucose metabolism, such as insulin and insulin-like growth-factors (IGFs) may contribute to breast cancer development. The present study analyzed the hypothesis that serum glucose, insulin levels, and IGF-I pattern are associated with breast cancer using a nested case-control study. Between 1987 and 1992, 10,786 women ages 35-69 were recruited in a prospective study in Italy. Women with history of cancer and on hormone therapy were excluded at baseline. At recruitment, blood samples were collected after a 12-h fast between 7:30 and 9:00 a.m. from all of the study participants. After 5.5 years, 144 breast cancer cases were identified among the participants of the cohort. Four matched controls were chosen for each breast cancer case from members of the cohort who did not develop breast cancer during the follow-up period. In premenopausal women, glucose was associated with breast cancer risk: the age, body mass index, and reproductive variable adjusted relative risk (RR) for the highest quartile of serum glucose versus the lowest was 2.8 [95% confidence interval (CI), 1.2-6.5], and P for trend was 0.02. Insulin showed a weaker association with breast cancer, the adjusted RR of the highest quartile versus the lowest was 1.7 (95% CI, 0.7-4.1), and P for trend was 0.14, whereas the adjusted RR of the highest quartile of IGF-I was 3.1 (95% CI, 1.1-8.6), and P for trend was 0.01. Increased levels of insulin-like growth factor binding protein-3 (IGFBP)-3 were related to breast cancer risk: the adjusted RR for the highest quartile was 2.1 (95% CI, 0.95-4.75), and P for trend was 0.02. In postmenopausal women, the associations of glucose, insulin, and IGF-1 pattern were associated with breast cancer risk in heavier subjects characterized by a body mass index higher than 26. These results indicate that chronic alteration of glucose metabolism is related to breast cancer development.

Adult↗

PubMedDate not supplied

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 life-style 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.

Adult↗

PubMedDate not supplied

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.

Age Distribution↗

PubMedDate not supplied

EPIC-Italy cohorts and multipurpose national surveys. A comparison of some socio-demographic and life-style characteristics.

BACKGROUND: EPIC-Italy cohort study recruited subjects who voluntarily accepted to participate in the project. From the self-selected bases of the population sample, some bias could derive in the data interpretation when risk estimation for cancer disease related to life-style factors is the principal concern. Knowledge of the bias related to self-selected sampling is important for better directing the interpretation of the EPIC-Italy study results. METHODS: We investigated the characteristics of volunteer subjects recruited in the EPIC-Italy cohorts and compared them with those of the randomly selected subjects recruited in the Multipurpose ISTAT Surveys realized in the same period (1993-1998) in which the EPIC-cohorts were recruited. RESULTS: We found some differences, and in particular a different attitude towards cigarettes smoking and wine consumption, between the EPIC cohort and the Multipurpose ISTAT Surveys, as well as among geographical areas within the EPIC cohort. CONCLUSIONS: The uneven distribution of some characteristics suggests that the self-selected subjects were characterized by an overall lower consumption of wine and cigarette smoking even when the educational level was considered. This could suggest a generally more healthy life-style among subjects recruited on a volountary bases.

Adult↗

PubMedDate not supplied

Relationship between plasma fatty acid composition and diet over previous years in the Italian centers of the European Prospective Investigation into Cancer and Nutrition (EPIC).

Fatty acid levels in plasma phospholipids were related to food intake over the previous year as estimated by semiquantitative food frequency questionnaires compiled by 280 men and 246 women from the EPIC centers of Varese, Turin, Florence and Ragusa (Italy). Fatty acid content was determined by gas chromatography and analyzed in relation to age, sex and center. The most important finding was that plasma monounsaturated fatty acid levels, mainly oleic acid, were associated with olive oil consumption (r = 0.28 men, r = 0.19 women, both P <0.01). To our knowledge, this is the first time that these non-essential plasma fatty acids have been related to their dietary source in a population eating a varied and freely chosen diet. We confirmed that long-chain n-3 fatty acids in plasma phospholipids are associated with fish consumption and that odd chain 15 : 0 and 17 : 0 fatty acid levels are associated with dairy products and pizza-with-mozzarella consumption. N-6 polyunsaturated fatty acid levels reflected dietary intake of seed oils, mayonnaise and biscuits. Alcohol intake was positively associated with palmitic and palmitoleic acid and negatively associated with linoleic acid. These associations suggest indirect relations between alcohol consumption and other features of diet, and also that ethanol has an effect on fat metabolism. We found numerous indirect relationships (ie, not due to dietary consumption of food sources of the fatty acids) between plasma fatty acids and diet, which we propose as due to the influence of complex life-style factors.

Adult↗

PubMedDate not supplied

Association between social class and food consumption in the Italian EPIC population.

AIMS AND BACKGROUND: The objectives of the present study were to validate the social stratification variables adopted by the European Prospective Investigation into Cancer and Nutrition (EPIC) by comparing them with data from another independent source and to evaluate the geographic and social distribution of eating habits in the Italian EPIC population. METHODS: The validation of the socioeconomic data collected by the EPIC study was performed with the Turin Longitudinal Study as gold standard and using Cohen's kappa statistics to evaluate the concordance between the studies. We then analyzed food groups based on the consumption of meat and fats, carbohydrates, sweets and alcohol, and on an index of the Mediterranean diet. The standardized scores for each food group were subdivided into quartiles, which were used to compare persons in the extreme quartiles. Analysis of the differences in eating habits by center and by educational level was conducted separately for men and women, calculating the prevalence rate ratios and controlling for age, area of birth and body mass index. RESULTS: Concordance between the two data sources was high for educational level and low for the social-class index based on occupation. Most of the eating habits considered to be potentially harmful (high consumption of meat or fats and alcohol and low consumption of olive oil and fish) were more frequent in Northern than in Southern Italy. These habits were inversely correlated with educational level, especially in the South. CONCLUSIONS: A significant improvement in health could be obtained in the Italian population if culturally and socioeconomically disadvantaged individuals were to abandon their diet rich in meat and fats, as done by more advantaged persons. In the absence of preventive interventions specifically addressed to disadvantaged groups, it is likely that social inequalities in mortality and morbidity will increase.

Adult↗