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E Riboli

Publications and source records attributed to E Riboli.

At least 73 records · Page 4Linked to original sources
PubMed2001

Determinants of circulating insulin-like growth factor (IGF)-I and IGF binding proteins 1-3 in premenopausal women: physical activity and anthropometry (Netherlands).

OBJECTIVE: Epidemiologic studies suggest that subjects with elevated plasma concentrations of insulin-like growth factor (IGF)-I are at increased risk of developing cancer. The objective of our study was to assess whether cancer risk factors such as lack of physical activity, obesity, and central body fat distribution are associated with plasma levels of IGF-I and related proteins (i.e. IGF binding proteins 1-3 and C-peptide). METHODS: A cross-sectional study was conducted in a population of 225 premenopausal women, aged 49-57, participating in the Prospect-EPIC study in the Netherlands. Plasma concentrations of IGF-I, IGFBP-1, IGFBP-2, IGFBP-3, and C-peptide were determined. On the day of blood collection height, weight, and waist and hip circumference were measured. Habitual physical activity was assessed using a validated self-administered questionnaire. RESULTS: Mean concentrations of plasma IGF-I, IGFBP-1, IGFBP-2, IGFBP-3, and C-peptide were 156.1, 14.3, 434.4, 3062, and 2.86 ng/ml, respectively. Women in the highest tertile for physical activity had lower plasma concentrations of IGF-I, IGFBP-3, and C-peptide, and higher concentrations of IGFBP-1 and IGFBP-2, as compared to women in the lowest tertile. However, these differences were not statistically significant. BMI and related measures were significantly inversely associated with IGFBP-1 and IGFBP-2, and positively with IGFBP-3 and C-peptide. Linear regression analyses showed that the non-significant association of physical activity with components of the plasma IGF system was further attenuated by adjusting for obesity and central body fat distribution. CONCLUSIONS: Our data suggest that an active lifestyle is not independently associated with the plasma IGF system. We did confirm that a lean body shape is associated with higher concentrations of IGFBP-1 and IGFBP-2, and possibly also with lower concentrations of IGF-I and IGFBP-3.

Aged↗
PubMed2001

Prospect-EPIC Utrecht: study design and characteristics of the cohort population. European Prospective Investigation into Cancer and Nutrition.

The European Prospective Investigation into Cancer and Nutrition (EPIC), which has been established in order to investigate the relations between nutrition and cancer, was initiated in 1990 and involves 10 European countries with heterogeneous dietary patterns and differing cancer incidence rates. This manuscript presents the design, recruitment and baseline characteristics of the Prospect-EPIC cohort co-ordinated in Utrecht, The Netherlands. The cohort is based on volunteers recruited among women participating in a regional breast cancer screening program. It comprises of 17,357 subjects aged 50-69 years at enrolment from Utrecht and vicinity, who have consented to participate in the study and its follow-up. Each participant filled out a general questionnaire and a food frequency questionnaire. Participants were also physically examined and have donated a blood sample. Participation rate was 34.5%. Blood samples were donated by most participants (97.5%) and detailed informed consents were obtained from 87.4% of participants. Mean age at enrolment was 57 years. Anthropometric, lifestyle and morbidity characteristics of the cohort population did not differ largely from those of similar study populations in The Netherlands. Based on the Prospect-EPIC population, we intend to conduct prospective total cohort, nested case-control or case-cohort studies, in order to investigate relations between consumption of certain food groups or nutrients and chronic diseases, including hormone dependant cancers such as breast, colon, endometrial and ovary cancers.

Aged↗
PubMed2001

Plasma carotenoids in relation to food consumption in Granada (southern Spain) and Malmö (southern Sweden).

We conducted a cross-sectional pilot study on healthy pre-menopausal women (aged 45-50 years) living in Granada, in the south of Spain (n = 39) and Malmö, in the south of Sweden (n = 38) in order to compare their plasma carotenoid levels and to investigate the relationship between the differences in food consumption. Plasma concentrations of six carotenoids were measured using high performance liquid chromatography, habitual diet (at individual level) was estimated by food frequency questionnaires and 24-hour diet recalls were used for standardised measurement of diet at group-level. We found that women in Granada consumed more fruit and vegetables than women in Malmö. Plasma concentrations of beta-cryptoxanthin, lycopene, zeaxanthin, total carotenoids and alpha-tocopherol were higher in Granada than in Malmö, although plasma concentrations of alpha-carotene and retinol were higher in Malmö. Both within and between study centres, consumption of fruit and vegetables correlated positively with plasma concentrations of different carotenoids. The study showed that differences in consumption of fruit and vegetables between the two European centres were reflected in plasma carotenoid concentrations.

Carotenoids↗
PubMed2001

Comparison of fatty acid profile in plasma phospholipids in women from Granada (southern Spain) and Malmö (southern Sweden).

We conducted a first pilot study on healthy women living in two countries with different dietary habits, Granada in the south of Spain and Malmö in the south of Sweden, in order to compare their levels of plasma phospholipid fatty acids, and to examine the relationship between the differences in food consumption. This study is part of a pilot study which is nested in the European Prospective Investigation into Cancer and Nutrition, a multi-centre prospective cohort study on diet, plasma concentrations of antioxidants and fatty acids, and markers of oxidative stress. Thirty-nine women in Granada and thirty-eight women in Malmö, aged 45-50 years (all pre-menopausal) were selected among the female participants in the cohorts from these two countries. Individual measurements of the women's habitual diet were obtained by a food frequency questionnaire. 24-hour diet recalls were used for the standardised measurement of diet at group level. Plasma phospholipid fatty acid composition was determined by capillary gas chromatography. We found a different fatty acid profile in plasma between the two populations, with higher mean levels of palmitic acid (16:0), palmitoleic acid (16:1) (n-7), oleic acid (18:1), alpha-linolenic acid (18:3) (n-3) and eicosapentaenoic acid (20:5) (n-3), and lower mean levels of stearic acid (18:0) in Malmö compared to Granada. Women in Malmö consumed more meat, alcoholic beverages and sugar, and less fish and shellfish than women in Granada. We conclude that the fatty acid composition in plasma phospholipids is different between women from the two European centres. For polyunsaturated fatty acids, differences were observed for (n-3) fatty acids. In relation to these differences, we observed that specific food intakes, particularly meat and fish, varied between the two centres.

Chromatography, Gas↗
PubMed2001

Serum carotenoids as biomarkers of fruit and vegetable consumption in the New York Women's Health Study.

OBJECTIVE: To investigate the usefulness of serum carotenoids as biomarkers of fruit and vegetable consumption. DESIGN: : Reproducibility study on three repeat measurements of serum carotenoids. Correlation analysis of carotenoids and dietary food intake, and regression analysis of potential predictive parameters for serum carotenoid levels. SETTING: New York, USA. SUBJECT: : Women participating in the New York Women's Health Study, a prospective study of sex hormones, diet and breast cancer. Forty-eight women with three repeat blood samples and 302 women having a blood sample and a dietary history questionnaire (including 47 subjects from the reproducibility study). RESULTS: Serum carotenoid concentrations were highly reproducible between one- and two-year repeat samples. Estimated fruit and vegetable consumption was positively correlated with serum carotenoid concentrations but correlation coefficients were low. Consumption of fruit was predictive for serum levels of beta-carotene, alpha-carotene and beta-cryptoxanthin, while vegetable consumption was predictive for serum beta-carotene, lutein, zeaxanthin and lycopene. Serum concentrations of cholesterol and triglycerides were predictive for serum carotenoids but adjustment for their levels had little or no influence on the correlation between fruit and vegetable consumption and serum carotenoid concentrations. CONCLUSIONS: One single serum measurement of alpha-carotene, beta-carotene and lutein can accurately rank subjects according to their usual serum level. Serum concentrations, however, correlate only moderately with estimated dietary intake of fruits or vegetables and should therefore be used with caution as biomarkers of fruit and vegetable intake.

Biomarkers↗
PubMed2001

Cancer prevention and diet: opportunities in Europe.

Over the past 20 years, a large number of epidemiological studies, particularly case-control and cohort studies, have been conducted to investigate the role of diet and the risk of developing different types of cancer. The most consistent finding so far is the association observed between consumption of vegetables and fruit and reduced risk of cancers of the digestive and respiratory tracts. More recently, evidence has accumulated indicating that high consumption of red meat (mainly beef, lamb and pork) and of preserved meat ('charcuterie') is specifically associated with a modest but significant increase in colorectal cancer risk. Finally, there is epidemiological evidence supporting an association between the risk of developing gastric cancer and the intake of salt and salt-preserved foods. Cancer incidence and dietary habits vary substantially across Europe, and the expected benefit of dietary changes may be somewhat different in different populations. Despite some uncertainty, it is generally agreed that an increase in the consumption of vegetables and fruits and a decrease in the intake of red meat, processed meat, alcoholic beverages, salt and salt-preserved foods should contribute to a reduction in the incidence of cancers of the digestive and respiratory tract.

Animals↗
PubMed2001

Circulating insulin-like growth factor-I and benign prostatic hyperplasia--a prospective study.

OBJECTIVE: The aim of this study was to investigate the role of insulin-like growth factor-I (IGF-I), a strongly mitogenic and anti-apoptotic factor, in the development of benign prostatic hyperplasia (BPH). The bioactivity of IGF-I within tissues depends on circulating levels, as well as on the local production of IGF-I and the presence of IGF-binding proteins (IGFBPs). The IGFBPs regulate the efflux of IGF-I to the extravascular space and the bioavailability of IGF-I within tissues. MATERIAL AND METHODS: Within the Northern Sweden Health and Disease Study, 60 cases of BPH defined by a history of prostate resection were identified, and two controls per case were selected. IGF-I, IGFBP-1, IGFBP-3 and insulin were measured by immuno-radiometric assays in stored plasma samples drawn a mean of 3.2 years before surgery. RESULTS: The risk of BPH increased with increasing quartile levels of IGF-I adjusted for IGFBP-3 (p(trend) = 0.10) up to a relative risk of 2.16 (95% confidence interval 0.83-5.64) for the highest quartile. The risk decreased with increasing levels of IGFBP-1 (p(trend) = 0.10). CONCLUSIONS: Our results suggest that elevated IGF-I bioactivity may stimulate the development of BPH; however, they were not statistically significant and require confirmation from larger studies.

Humans↗
PubMed2001

Inverse correlation between alcohol consumption and lymphocyte levels of 8-hydroxydeoxyguanosine in humans.

In a cross-sectional study of 115 premenopausal non-smoking women, we examined the relationship between lymphocyte levels of 8-hydroxy-2'-deoxyguanosine (8-oxodGuo) and habitual alcohol consumption. The study was conducted in four different regions of Europe, including Potsdam (Germany), Turin (Italy), Malmö (Sweden) and Granada (Spain). Mean 8-oxodGuo levels differed significantly across study centres (P = 0.001), with the highest levels in Granada [2.17 8-oxodGuox10(-6) 2'-deoxyguanosine (95% confidence interval 1.27-4.40)] and lowest levels in Turin [1.19 (0.36-4.29)]. Mean levels of total alcohol intake and of types of alcoholic beverages consumed (wine, fortified wines, beer and cider) also differed across the study centres (P < 0.05), with the highest total alcohol consumption in Turin, and the lowest intake in GRANADA: When combining all the data, but adjusting for study centre, individual 8-oxodGuo level correlated inversely with alcohol intake. This inverse association remained unaltered after further adjustment for Quetelet Index, fruit and vegetable consumption, and plasma carotenoid levels. Furthermore, the inverse association was also observed for each of the study centres separately, and for different beverage types, with the exception of Granada, where the majority of women were non-drinkers and where alcohol intakes were also very low for the consumers. Finally, on a group level, mean levels of 8-oxodGuo and alcohol intake were also inversely associated between the four study centres. The finding of a relationship between alcohol consumption and 8-oxodGuo in lymphocytes was unexpected and not based on a prior hypothesis. This finding consequently requires confirmation from a randomized intervention study.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

Risk of breast cancer in relation to anthropometry, blood pressure, blood lipids and glucose metabolism: a prospective study within the Malmö Preventive Project.

Insulin resistance may be a risk factor for breast cancer, possibly through increased levels of oestrogens or insulin-like growth factor I. Insulin resistance has been associated with obesity, hypertension, dyslipidaemia and impaired glucose tolerance. We studied the relation of these factors to breast cancer risk in a prospective cohort study of 9738 women. Menopausal status was defined a priori, and 112 cases of invasive breast carcinoma occurred in women who were premenopausal at baseline and 157 cases in subjects who were peri/postmenopausal. Relative risks (RR) for breast cancer were calculated by Cox's proportional hazards analysis for different quartiles of height, weight, body mass index, blood pressure, pulse rate and serum levels of total cholesterol, triglycerides, fasting blood glucose and glucose at 120 min after an oral dose of glucose. Peri/postmenopausal women had a significantly increased age-adjusted relative risk of breast cancer associated with height (RR = 1.78 for the highest versus lowest quartile), and the RR was increased over quartiles of cholesterol levels (P-value for trend: 0.05). No other significant associations were found. Adjustments for potential confounding factors or restriction of the analysis to cases and person-years before 55 years of age (premenopausal women), or after 55 years (peri/postmenopausal women), did not change

Anthropometry↗
PubMed2001

A cross-sectional study of IGF-I determinants in women.

Evidence is accumulating that elevated circulating insulin-like growth factor I (IGF-I) is related to increased cancer risk. The identification of hormonal, reproductive and lifestyle characteristics influencing its synthesis and bioavailability is of particular interest. Data from 400 women, who served as controls in two case-control studies nested within the same prospective cohort study, were combined. IGF-I, IGF-binding proteins 1, 2 and 3 (IGFBP-1, -2, -3) and insulin were measured in serum samples from all subjects and cotinine in 186 samples. Age appears to be the most important determinant of total IGF-I levels in women. Anthropometric measures, such as body mass index (BMI) or waist-to-hip ratio (WHR) do not seem to influence total IGF-I concentrations in peripheral blood, but may modulate IGF-I bioavailability through insulin-dependent changes in IGFBP-1 and -2 concentrations. Age at menarche, phase of the menstrual cycle at blood draw, parity, menopause, past oral contraceptive or hormone replacement therapy use, and tobacco smoking do not appear to exert an independent effect on IGF-I and its binding proteins. There was some suggestion that regular physical activity may increase total IGF-I and that women with positive family history of breast cancer might have higher IGF-I levels than those without such diagnosis in their relatives.

Age Factors↗
PubMed2001

Meat consumption and colorectal cancer: a review of epidemiologic evidence.

This article reviews the epidemiologic evidence on colorectal cancer risk and meat consumption from 32 case-control and 13 cohort studies published in English from 1970 to 1999 and retrieved from the Medline database. The results support the hypothesis that meat consumption is associated with a modest increase in colorectal cancer risk. This association, however, seems to have been more consistently found for red meat and processed meat. The studies on cooking methods and meat "doneness" are not consistent and the evidence is not conclusive.

Animals↗
PubMed2001

Ratios of IGF-I, IGF binding protein-3, and prostate-specific antigen in prostate cancer detection.

Recent studies have suggested that IGF-I and IGF-binding protein (IGFBP)-3, in combination with prostate-specific antigen (PSA), may enhance prostate cancer detection. In this study, we sought to determine the effect on the prediction of future prostate cancer occurrence by incorporating ratios of total and free PSA, IGF-I, IGFBP-3 into PSA testing. Within a population-based prospective cohort study, we investigated the validity (sensitivity and specificity) of plasma concentrations of total and free PSA, IGF-I, and IGFBP-3 and combinations thereof, in 114 cases and 97 controls, in the range of 1.75-13.5 microg/l for PSA, as used by Khosravi et al. (See Ref. 7 ). Validity estimated by the area under the curve in receiver operator characteristics analysis (with 95% confidence interval) for total PSA was 0.78 (range, 0.71-0.84); total/free PSA, 0.69 (range, 0.62-0.76); total PSA/IGF-I, 0.72 (range, 0.65-0.79); free PSA/IGF-I, 0.55 (range, 0.48-0.63); total PSA/IGFBP-3, 0.74 (range, 0.68-0.81); and free PSA/IGFBP-3, 0.57 (range, 0.49-0.64). Analysis of ratios of IGF-I, IGFBP-3, and free and total PSA did not improve validity of PSA testing in the prediction of future occurrence of prostate cancer. It is unlikely that these combinations will improve prostate cancer detection.

Biomarkers, Tumor↗
PubMed2001

Reliability and validity of commercially available, direct radioimmunoassays for measurement of blood androgens and estrogens in postmenopausal women.

In large-scale epidemiological studies on endogenous sex steroids and cancer risk, direct immunoassays of circulating hormone levels have the advantage of being fast and comparatively inexpensive while requiring only small sample volumes. On the other hand, indirect assays after organic extraction and chromatographic prepurification have the advantage of reducing specific interferences and matrix effects and hence are thought to have better validity. We compared direct assays of testosterone (T, six different assays), Delta4-androstenedione (A, four assays), estrone (E(1), one assay), and 17beta-estradiol (E(2), five assays) with measurements obtained by an indirect assay in a representative subset of 20 postmenopausal women who were part of a large prospective cohort study. Within-batch reproducibilities of the subject rankings by relative hormone levels were good (intraclass correlations >0.89) for all direct assays tested. Between batches, reproducibilities generally were also acceptable (r > 0.80) to good (r > 0.90) in terms of Pearson's correlations. The between-batch reproducibility in terms of intraclass correlations was systematically lower in terms of Pearson's correlations, however, because of between-batch variations in the absolute scale of measurements. The relative validity of direct versus indirect assays in terms of the subjects' ranking by relative hormone levels was also high for most of the kits tested for T, A, and E(1) (Pearson's correlations between 0.70 and 0.89) but was high for only two kits of five tested for E(2) (correlations of 0.86 and 0.84). On an absolute scale, mean measurement values were generally higher for direct assays than for the indirect assay and, for each hormone, varied substantially, depending on the kit used. Overall, the results of this study show that, with careful selection, commercial kits for direct radioimmunoassays of steroid hormones in postmenopausal serum can be found that may allow a reliable estimation of relative risks in epidemiological studies. However, standardization of the absolute scale of assays remains problematic.

Aged↗
PubMed2000

Plasma insulin-like growth factor-I, insulin-like growth factor-binding proteins, and prostate cancer risk: a prospective study.

BACKGROUND: Recent studies have suggested that men with elevated plasma levels of insulin-like growth factor-I (IGF-I) may have an increased risk of prostate cancer. Furthermore, IGF-binding proteins (IGFBPs) and insulin can modulate the activity of IGF-I. In this study, we sought to determine the role of IGF-I as well as IGFBPs-1, -2, and -3 and insulin as possible etiologic factors for prostate cancer. METHODS: We conducted a nested case-control study within the Northern Sweden Health and Disease Cohort Study. We measured levels of IGF-I, IGFBP-1, IGFBP-2, IGFBP-3, and insulin in plasma samples from 149 men who had a diagnosis of prostate cancer between 1 month and 10 years after blood collection and among 298 control men. All statistical tests are two-sided. RESULTS: Case subjects had statistically significantly higher mean levels of IGF-I than control subjects (229 ng/mL; 95% confidence interval [CI] = 218-240 ng/mL] versus 214 ng/mL [95% CI = 208-221 ng/mL]; P =.02) and IGFBP-3 (2611 ng/mL [95% CI = 2518-2704 ng/mL] versus 2498 ng/mL [95% CI = 2437-2560 ng/mL]; P =.04). Conditional logistic regression analyses showed increases in prostate cancer risk with rising levels of IGF-I (P:(for trend) =.02) and IGFBP-3 (P(for trend) =.03). In case subjects younger than 59 years at the time of blood collection, the risk associated with increased IGF-I was higher (P:(for trend) =.01), whereas the risk associated with increased IGFBP-3 was lower (P(for trend) =.44) than the corresponding risks in the full cohort. Prostate cancer risk was not associated with levels of IGFBP-1, IGFBP-2, or insulin. CONCLUSIONS: Prostate cancer risk is increased in men with elevated plasma IGF-I. This association was particularly strong in younger men in this study, suggesting that circulating IGF-I may be specifically involved in the early pathogenesis of prostate cancer.

Age Factors↗
PubMed2000

Serum C-peptide, insulin-like growth factor (IGF)-I, IGF-binding proteins, and colorectal cancer risk in women.

BACKGROUND: Leading a Western lifestyle, being overweight, and being sedentary are associated with an increased risk of colorectal cancer. Recent theories propose that the effects of these risk factors may be mediated by increases in circulating insulin levels and in the bioactivity of insulin-like growth factor (IGF)-I. To test this hypothesis, we conducted a case-control study nested within a cohort of 14 275 women in New York. METHODS: We used blood samples that had been obtained from these women from March 1985 through June 1991 and stored in a biorepository. C-peptide (a marker for insulin secretion), IGF-I, and IGF-binding proteins (IGFBPs)-1, -2, and -3 were assayed in the serum of 102 women who subsequently developed colorectal cancer and 200 matched control subjects. Logistic regression was used to relate cancer risk to these peptide levels, by adjustment for other risk factors. All statistical tests used are two-sided. RESULTS: Colorectal cancer risk increased with increasing levels of C-peptide (P:(trend) =.001), up to an odds ratio (OR) of 2. 92 (95% confidence interval [CI] = 1.26-6.75) for the highest versus the lowest quintiles, after adjustment for smoking. For colon cancer alone (75 case subjects and 146 control subjects), ORs increased up to 3.96 (95% CI = 1.49-10.50; P:(trend) <.001) for the highest versus the lowest quintiles. A statistically significant decrease in colorectal cancer risk was observed for increasing levels of IGFBP-1 (P:(trend) =.02; OR in the upper quintile = 0.48 [95% CI = 0.23-1. 00]), as well as for the highest quintile of IGFBP-2 levels (P:(trend) =.06; OR = 0.38 [95% CI = 0.15-0.94]). Colorectal cancer risk showed a modest but statistically nonsignificant positive association with levels of IGF-I and was statistically significantly increased for the highest quintile of IGFBP-3 (OR = 2.46 [95% CI = 1. 09-5.57]). CONCLUSIONS: Chronically high levels of circulating insulin and IGFs associated with a Western lifestyle may increase colorectal cancer risk, possibly by decreasing IGFBP-1 and increasing the bioactivity of IGF-I.

Adult↗
PubMed2000

Fatty acid composition of the red blood cell membrane in relation to menopausal status.

PURPOSE: Menopausal status effects female anatomical functioning at a variety of system-wide and cellular levels, including cellular membrane composition. This study analyzed a nested case-control ORDET data set of 433 pre and post-menopausal breast cancer controls to examine the effects of menopausal status on the fatty acid composition of the red blood cell membrane.METHODS: ORDET is a prospective cohort study conducted in Italy to investigate the etiologic role of hormones and diet in breast cancer development. The fatty acid composition was measured and analyzed by gas chromotography, comparing retention time with standard measurement. Twenty-two individual fatty acids were measured, recorded, and categorized into four fatty acid groups: saturated, monounsaturated, polyunsaturated n-6 (PUFA n-6), and polyunsaturated (PUFA n-3) fatty acids.RESULTS: Post-menopausal women had consistently lower mean values for all four fatty acid categories and all individual fatty acids. Statistically significant mean differences, by menopausal status, were observed for three of the four fatty acid categories: saturated fatty acids (p = 0.006), PUFA n-6 acids (p = 0.001), and PUFA n-3 acids (p = 0.000). The biggest statistically significant differences in mean values among individual fatty acids for each category were observed for Palmitic acid (p = 0.009), Oleic acid (p = 0.040), Linoleic acid (p = 0.000), and Docosahexaenoic acid (p = 0.000). Individual fatty acids were also less highly correlated among post-menopausal women.CONCLUSIONS: There was an observed relationship between menopausal status and the fatty acid composition of the red blood cell membrane that warrants further study. This relationship may contribute to the physiological and psychological changes that occur during and after menopause, and may have far-reaching implications for women's health.

Journal Article↗