Fibre intake and the development of inflammatory bowel disease: A European prospective multi-centre cohort study (EPIC-IBD)

BACKGROUND AND AIMS

Population-based prospective cohort studies investigating fibre intake and development of inflammatory bowel disease are lacking. Our aim was to investigate the association between fibre intake and the development of Crohn's disease [CD] and ulcerative colitis [UC] in a large European population.

METHODS

In total, 401326 participants, aged 20-80 years, were recruited in eight countries in Europe between 1991 and 1998. At baseline, fibre intake [total fibres, fibres from fruit, vegetables and cereals] was recorded using food frequency questionnaires. The cohort was monitored for the development of inflammatory bowel disease. Each case was matched with four controls and odds ratios [ORs] for the exposures were calculated using conditional logistic regression. Sensitivity analyses according to smoking status were computed.

RESULTS

In total, 104 and 221 participants developed incident CD and UC, respectively. For both CD and UC, there were no statistically significant associations with either quartiles, or trends across quartiles, for total fibre or any of the individual sources. The associations were not affected by adjusting for smoking and energy intake. Stratification according to smoking status showed null findings apart from an inverse association with cereal fibre and CD in non-smokers [Quartile 4 vs 1 OR = 0.12, 95% confidence interval = 0.02-0.75, p = 0.023, OR trend across quartiles = 0.50, 95% confidence interval = 0.29-0.86, p = 0.017].

CONCLUSION

The results do not support the hypothesis that dietary fibre is involved in the aetiology of UC, although future work should investigate whether there may be a protective effect of specific types of fibre according to smoking status in CD.

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.

Diabetes and onset of natural menopause: results from the European Prospective Investigation into Cancer and Nutrition

STUDY QUESTION

Do women who have diabetes before menopause have their menopause at an earlier age compared with women without diabetes?

SUMMARY ANSWER

Although there was no overall association between diabetes and age at menopause, our study suggests that early-onset diabetes may accelerate menopause.

WHAT IS KNOWN ALREADY

Today, more women of childbearing age are being diagnosed with diabetes, but little is known about the impact of diabetes on reproductive health.

STUDY DESIGN, SIZE, DURATION

We investigated the impact of diabetes on age at natural menopause (ANM) in 258 898 women from the European Prospective Investigation into Cancer and Nutrition (EPIC), enrolled between 1992 and 2000.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Determinant and outcome information was obtained through questionnaires. Time-dependent Cox regression analyses were used to estimate the associations of diabetes and age at diabetes diagnosis with ANM, stratified by center and adjusted for age, smoking, reproductive and diabetes risk factors and with age from birth to menopause or censoring as the underlying time scale.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, no association between diabetes and ANM was found (hazard ratio (HR) = 0.94; 95% confidence interval (CI) 0.89-1.01). However, women with diabetes before the age of 20 years had an earlier menopause (10-20 years: HR = 1.43; 95% CI 1.02-2.01, <10 years: HR = 1.59; 95% CI 1.03-2.43) compared with non-diabetic women, whereas women with diabetes at age 50 years and older had a later menopause (HR = 0.81; 95% CI 0.70-0.95). None of the other age groups were associated with ANM.

LIMITATIONS, REASONS FOR CAUTION

Strengths of the study include the large sample size and the broad set of potential confounders measured. However, results may have been underestimated due to survival bias. We cannot be sure about the sequence of the events in women with a late age at diabetes, as both events then occur in a short period. We could not distinguish between type 1 and type 2 diabetes.

WIDER IMPLICATIONS OF THE FINDINGS

Based on the literature, an accelerating effect of early-onset diabetes on ANM might be plausible. A delaying effect of late-onset diabetes on ANM has not been reported before, and is not in agreement with recent studies suggesting the opposite association.

STUDY FUNDING/COMPETING INTERESTS

The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l'Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ) and Federal Ministry of Education and Research (BMMF) (Germany); Ministry of Health and Social Solidarity, Stavros Niarchos Foundation and Hellenic Health Foundation (Greece); Italian Association for Research on Cancer (AIRC) and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC-2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), Regional Governments of Andalucía, Asturias, Basque Country, Murcia (no. 6236) and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Scientific Council and Regional Government of Skåne and Västerbotten (Sweden); Cancer Research UK, Medical Research Council, Stroke Association, British Heart Foundation, Department of Health, Food Standards Agency, and Wellcome Trust (UK). None of the authors reported a conflict of interest.

Dietary folate intake and breast cancer risk: European prospective investigation into cancer and nutrition

BACKGROUND

There is limited evidence on the association between dietary folate intake and the risk of breast cancer (BC) by hormone receptor expression in the tumors. We investigated the relationship between dietary folate and BC risk using data from the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

A total of 367993 women age 35 to 70 years were recruited in 10 European countries. During a median follow-up of 11.5 years, 11575 women with BC were identified. Dietary folate intake was estimated from country-specific dietary questionnaires. Cox proportional hazards regression models were used to quantify the association between dietary variables and BC risk. BC tumors were classified by receptor status. Subgroup analyses were performed by menopausal status and alcohol intake. Intake of other B vitamins was considered. All statistical tests were two-sided.

RESULTS

A borderline inverse association was observed between dietary folate and BC risk (hazard ratio comparing top vs bottom quintile [HRQ5-Q1] = 0.92, 95% CI = 0.83 to 1.01, P trend = .037). In premenopausal women, we observed a statistically significant trend towards lower risk in estrogen receptor-negative BC (HRQ5-Q1 = 0.66, 95% CI = 0.45 to 0.96, P trend = .042) and progesterone receptor-negative BC (HRQ5-Q1 = 0.70, 95% CI = 0.51 to 0.97, P trend = .021). No associations were found in postmenopausal women. A 14% reduction in BC risk was observed when comparing the highest with the lowest dietary folate tertiles in women having a high (>12 alcoholic drinks/week) alcohol intake (HRT3-T1 = 0.86, 95% CI = 0.75 to 0.98, P interaction = .035).

CONCLUSIONS

Higher dietary folate intake may be associated with a lower risk of sex hormone receptor-negative BC in premenopausal women.

[Anaphylaxis to blue dyes]

In medicine, vital blue dyes are mainly used for the evaluation of sentinel lymph nodes in oncologic surgery. Perioperative anaphylaxis to blue dyes is a rare but significant complication. Allergic reactions to blue dyes are supposedly IgE-mediated and mainly caused by triarylmethanes (patent blue and isosulfane blue) and less frequently by methylene blue. These substances usually do not feature on the anesthesia record and should not be omitted from the list of suspects having caused the perioperative reaction, in the same manner as latex and chlorhexidine. The diagnosis of hypersensitivity to vital blue dyes can be established by skin test. We illustrate this topic with three clinical cases.

[Genetic predispositions in drug allergy: the role of HLA]

The pathophysiology of drug allergy is complex and relies on the interaction between the drug and the immune system in combination with environmental factors, in particular viruses. Genetic predisposition plays an important role in drug allergy. Recent publications have shown the importance of HLA genes, particularly in the delayed hypersensitivity reactions. In fact, particular HLA alleles were identified as risk factors in the development of severe allergic reactions to certain drugs, identifying people at risk of hypersensitivity before initiation of specific treatment. In the future, identification of other alleles in HLA genes will improve patients care by preventing hypersensitivity reactions associated with significant morbidity and mortality.

Association between high dietary intake of the n-3 polyunsaturated fatty acid docosahexaenoic acid and reduced risk of Crohn's disease

BACKGROUND

There are plausible mechanisms for how dietary docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, could prevent Crohn's disease (CD).

AIM

To conduct a prospective study to investigate the association between increased intake of DHA and risk of CD.

METHODS

Overall, 229 702 participants were recruited from nine European centres between 1991 and 1998. At recruitment, dietary intakes of DHA and fatty acids were measured using validated food frequency questionnaires. The cohort was monitored through to June 2004 to identify participants who developed incident CD. In a nested case-control analysis, each case was matched with four controls; odds ratios (ORs) were calculated for quintiles of DHA intake, adjusted for total energy intake, smoking, other dietary fatty acids, dietary vitamin D and body mass index.

RESULTS

Seventy-three participants developed incident CD. All higher quintiles of DHA intake were inversely associated with development of CD; the highest quintile had the greatest effect size (OR = 0.07; 95% CI = 0.02-0.81). The OR trend across quintiles of DHA was 0.54 (95% CI = 0.30-0.99, Ptrend  = 0.04). Including BMI in the multivariate analysis, due to its correlation with dietary fat showed similar associations. There were no associations with the other dietary fatty acids studied.

CONCLUSION

There were inverse associations, with a biological gradient between increasing dietary docosahexaenoic acid intakes and incident Crohn's disease. Further studies in other populations should measure docosahexaenoic acid to determine if the association is consistent and the hypothesis tested in randomised controlled trials of purely docosahexaenoic acid supplementation.

Alcohol consumption and risk of type 2 diabetes in European men and women: influence of beverage type and body size The EPIC-InterAct study

OBJECTIVE

To investigate the association between alcohol consumption and type 2 diabetes, and determine whether this is modified by sex, body mass index (BMI) and beverage type.

DESIGN

Multicentre prospective case-cohort study.

SETTING

Eight countries from the European Prospective Investigation into Cancer and Nutrition cohort.

SUBJECTS

A representative baseline sample of 16 154 participants and 12 403 incident cases of type 2 diabetes.

INTERVENTIONS

Alcohol consumption assessed using validated dietary questionnaires.

MAIN OUTCOME MEASURES

Occurrence of type 2 diabetes based on multiple sources (mainly self-reports), verified against medical information.

RESULTS

Amongst men, moderate alcohol consumption was nonsignificantly associated with a lower incidence of diabetes with a hazard ratio (HR) of 0.90 (95% CI: 0.78-1.05) for 6.1-12.0 versus 0.1-6.0 g day(-1) , adjusted for dietary and diabetes risk factors. However, the lowest risk was observed at higher intakes of 24.1-96.0 g day(-1) with an HR of 0.86 (95% CI: 0.75-0.98). Amongst women, moderate alcohol consumption was associated with a lower incidence of diabetes with a hazard ratio of 0.82 (95% CI: 0.72-0.92) for 6.1-12.0 g day(-1) (P interaction gender <0.01). The inverse association between alcohol consumption and diabetes was more pronounced amongst overweight (BMI ≥ 25 kg m(-2) ) than normal-weight men and women (P interaction < 0.05). Adjusting for waist and hip circumference did not alter the results for men, but attenuated the association for women (HR=0.90, 95% CI: 0.79-1.03 for 6.1-12.0 g day(-1) ). Wine consumption for men and fortified wine consumption for women were most strongly associated with a reduced risk of diabetes.

CONCLUSIONS

The results of this study show that moderate alcohol consumption is associated with a lower risk of type 2 diabetes amongst women only. However, this risk reduction is in part explained by fat distribution. The relation between alcohol consumption and type 2 diabetes was stronger for overweight than normal-weight women and men.

The association of education with long-term weight change in the EPIC-PANACEA cohort

BACKGROUND/OBJECTIVES

Cross-sectionally, educational attainment is strongly associated with the prevalence of obesity, but this association is less clear for weight change during adult life. The objective of this study is to examine the association between educational attainment and weight change during adult life in the European Prospective Investigation into Cancer and Nutrition (EPIC).

SUBJECTS/METHODS

EPIC is a cohort study with 361,467 participants and up to 10 years of follow-up. Educational attainment was categorized according to the highest obtained school level (primary school or less, vocational secondary training, other secondary education and university). Multivariate mixed-effects linear regression models were used to study education in relation to weight at age 20 years (self-reported), to annual change in weight between age 20 years and measured weight at recruitment, and to annual change in weight during follow-up time.

RESULTS

Higher educational attainment was associated with on average a lower body mass index (BMI) at age 20 years and a lower increase in weight up to recruitment (highest vs lowest educational attainment in men: -60 g per year (95% confidence interval (CI) -80; -40), women -110 g per year (95% CI -130; -80)). Although during follow-up after recruitment an increase in body weight was observed in all educational levels, gain was lowest in men and women with a university degree (high vs low education -120 g per year (95% CI -150; -90) and -70 g per year (95% CI -90; -60), respectively).

CONCLUSIONS

Existing differences in BMI between higher and lower educated individuals at early adulthood became more pronounced during lifetime, which possibly impacts on obesity-related chronic disease risk in persons with lower educational attainment.

Aspirin in the aetiology of Crohn's disease and ulcerative colitis: a European prospective cohort study

BACKGROUND

Aspirin has detrimental effects on the gastrointestinal tract mucosa and may play a role in the aetiology of inflammatory bowel disease.

AIM

To investigate if the regular use of aspirin is associated with the development of Crohn's disease (CD) and ulcerative colitis (UC) using, for the first time, a prospective cohort study design.

METHODS

A total of 135,780 men and women in Europe, aged 30-74years, were recruited into the European Prospective Investigation into Cancer and Nutrition study. Participants completed questionnaires at baseline detailing their regular aspirin use and were then followed up to identify those who developed either incident CD or UC. Each case was matched with four controls and odds ratios (OR) were calculated, adjusting for cigarette smoking. Potential interactions between aspirin and smoking were assessed.

RESULTS

A total of 35 participants developed CD and a further 84 were diagnosed with UC. Regular aspirin intake was positively associated with the risk of developing CD (OR=6.14, 95% CI=1.76-21.35). In those who took aspirin and smoked there was no detectable increased risk of CD (OR=0.30, 95% CI=0.03-3.08). No association was found between regular aspirin use and UC (OR=1.29, 95% CI=0.67-2.46).

CONCLUSIONS

A strong positive association between regular aspirin use and CD, but not UC, was observed. The data suggest that regular aspirin use should be measured in epidemiological work on CD. If such findings are consistent in other work then aspirin may affect the development of CD in a middle-aged to elderly population.

The association of lifetime alcohol use with measures of abdominal and general adiposity in a large-scale European cohort

BACKGROUND/OBJECTIVES

The relation between lifetime use of alcohol and measures of abdominal and general adiposity is unknown.

SUBJECTS/METHODS

Among 99,381 men and 158,796 women of the European Prospective Investigation into Cancer and Nutrition (EPIC) study, means of waist circumference (WC), waist-to-hip-ratio (WHR) and body mass index (BMI), and odds ratios (OR) for a larger WC than predicted for a given BMI (WClp=positive residuals of gender specific linear regression of BMI on WC) across categories of average lifetime use of alcohol (total, from wine and from beer) were calculated, all adjusted for socio-demographic, lifestyle and health factors.

RESULTS

WC, WHR and BMI in men using lifetime ≤6 g/d alcohol were 95.1 cm, 0.942 and 27.3 kg/m(2), and 96.2 cm, 0.961 and 28.3 kg/m(2) when using >96 g/d. WC and WHR in women was 83.2 cm and 0.813 for ≤6 g/d, and 84.6 cm and 0.830 for >60 g/d, whereas BMI deviated only slightly with the lowest BMI (26.7 kg/m(2)) observed for >6-24 g/d. Compared with ≤6 g/d, OR for a WClp in both genders increased steadily across categories of alcohol use (up to 1.40 (95% confidence interval 1.32, 1.49) in men using >60 g/d and 1.63 (1.54, 1.73) in women using >24 g/d), though increase was higher for alcohol from beer than from wine (P for difference between beer and wine<0.001 (men) and=0.002 (women)).

CONCLUSION

Lifetime alcohol use is positively related to abdominal and general adiposity in men, possibly following the male weight gain pattern; in women, it is positively related only to abdominal adiposity. In this context, beer may contribute additionally to abdominal adiposity.

Linoleic acid, a dietary n-6 polyunsaturated fatty acid, and the aetiology of ulcerative colitis: a nested case-control study within a European prospective cohort study

OBJECTIVE

Dietary linoleic acid, an n-6 polyunsaturated fatty acid, is metabolised to arachidonic acid, a component of colonocyte membranes. Metabolites of arachidonic acid have pro-inflammatory properties and are increased in the mucosa of patients with ulcerative colitis. The aim of this investigation was to conduct the first prospective cohort study investigating if a high dietary intake of linoleic acid increases the risk of developing incident ulcerative colitis.

DESIGN AND SETTING

Dietary data from food frequency questionnaires were available for 203 193 men and women aged 30-74 years, resident in the UK, Sweden, Denmark, Germany or Italy and participating in a prospective cohort study, the European Prospective Investigation into Cancer and Nutrition (EPIC). These participants were followed up for the diagnosis of ulcerative colitis. Each case was matched with four controls and the risk of disease calculated by quartile of intake of linoleic acid adjusted for gender, age, smoking, total energy intake and centre.

RESULTS

A total of 126 participants developed ulcerative colitis (47% women) after a median follow-up of 4.0 years (range, 1.7-11.3 years). The highest quartile of intake of linoleic acid was associated with an increased risk of ulcerative colitis (odds ratio (OR) = 2.49, 95% confidence interval (CI) = 1.23 to 5.07, p = 0.01) with a significant trend across quartiles (OR = 1.32 per quartile increase, 95% CI = 1.04 to 1.66, p = 0.02 for trend).

CONCLUSIONS

The data support a role for dietary linoleic acid in the aetiology of ulcerative colitis. An estimated 30% of cases could be attributed to having dietary intakes higher than the lowest quartile of linoleic acid intake.

Beer consumption and the 'beer belly': scientific basis or common belief?

BACKGROUND/OBJECTIVES

The term 'beer belly' expresses the common belief that beer consumption is a major determinant of waist circumference (WC). We studied the gender-specific associations between beer consumption and WC (partially in relation to body weight and hip circumference (HC) change).

PARTICIPANTS/METHODS

Within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study (7876 men, 12 749 women), cross-sectional associations were investigated applying general linear models. Prospective analyses of baseline beer consumption and an 8.5-year WC change were assessed using multivariate general linear models and polytomous logistic regression. To test the site-specific effect of beer consumption on WC, an adjustment for concurrent changes in body weight and HC was carried out. In addition, the relationship between change in beer consumption and change in WC was studied.

RESULTS

A positive association in men and no association in women were seen between beer consumption and WC at baseline. Men consuming 1000 ml/d beer were at 17% higher risk for WC gain compared with very light consumers. Significantly lower odds for WC gain (odds ratio=0.88; 95% confidence interval 0.81, 0.96) were found in beer-abstaining women than in very-light-drinking women. The adjustment for concurrent body weight and HC change diminished effect estimates notably, explaining most of the association between beer and change in WC. Decreasing beer consumption was related to higher relative odds for WC loss, although not statistically significant.

CONCLUSIONS

Beer consumption leads to WC gain, which is closely related to concurrent overall weight gain. This study does not support the common belief of a site-specific effect of beer on the abdomen, the beer belly.

Die Rolle des Gemeinsamen Krebsregisters bei der Identifizierung von Krebsfällen in der EPIC-Potsdam-Studie - Ergebnisse des ersten Datenabgleichs

AIM

The follow-up of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study has been identifying cancer diagnoses by an active follow-up through participant's self-report which is then confirmed by pathology registries or medical doctors. To utilise another source of information, a record linkage was performed with the Common Cancer Registry (CCR) of the states of Berlin, Brandenburg, Mecklenburg-Western Pomerania, Saxony-Anhalt and of the free states Saxony and Thuringia in November 2001, using the EPIC-Potsdam database of compliant study participants at that point in time (n = 27 087). This methodological study compares data of identified cancer cases in the EPIC-Potsdam study with those generated through the record linkage.

METHODS

The GKR identified 1468 study participants of the EPIC-Potsdam study. Cases (n = 108) with non-melanoma skin cancer were excluded. A separate analysis was done for prevalent (date of cancer diagnosis before baseline examination) and incident cancers (date of diagnosis after baseline examination). We examined how many subjects with at least one cancer were known to EPIC-Potsdam and the CCR, how many had been known only to the CCR and how many only to the EPIC-Potsdam study. Of incident cancer cases each diagnosis was counted. It was analyzed whether the diagnoses as they had been collected by EPIC-Potsdam were identified by the record linkage. Focus was on the diagnoses that had been unknown in EPIC-Potsdam before. The concordance of information from both sources was also considered.

RESULTS

According to the record linkage, 1298 subjects with at least one prevalent cancer were identified in the EPIC-Potsdam cohort, 593 (46 %) of whom were identified in both data sources, 241 (19 %) were newly identified, and 464 (36 %) participants self-reported at least one prevalent tumour which was not identified through the record linkage. Seven tumours were diagnosed before 1961 (the CCR's computerised data are only available since 1961). Fifty-seven percent (n = 187) of all tumours which could not be identified in the cancer registry dated from 1990 - 1995. After completion of the record linkage a total of 582 medically verified incident cancer cases were identified. These comprised 397 medically verified cases that were identified in the EPIC-cohort study prior to the record linkage, 18 self-reported cases where the medical verification was pending, and 167 newly identified cases. Eighty-five of the latter cases have not been identified by other sources in the two following years after record linkage indicating that 15 % of the medically verified cases have been found solely through the linkage.

CONCLUSION

The EPIC-Potsdam study had a significant benefit of the record linkage due to both the additional identification and verification of prevalent and incident cancer cases, as well as a timely advanced identification of incident diagnoses. The record linkage with the cancer registry improved the quality of the endpoint data of the EPIC-Potsdam study.

Physical activity of subjects aged 50-64 years involved in the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVE

To describe physical activity of participants in the European Prospective Investigation into Cancer and Nutrition (EPIC).

DESIGN

A cross-sectional analysis of baseline data of a European prospective cohort study.

SUBJECTS

This analysis was restricted to participants in the age group 50-64 years, which was represented in all EPIC centres. It involved 236 386 participants from 25 centres in nine countries. In each EPIC centre, physical activity was assessed by standardised and validated questions. Frequency distribution of type of professional activity and participation in non-professional activities, and age-adjusted means, medians and percentiles of time dedicated to non-professional activities are presented for men and women from each centre.

RESULTS

Professional activity was most frequently classified as sedentary or standing in all centres. There was a wide variation regarding participation in different types of non-professional activities and time dedicated to these activities across EPIC centres. Over 80% of all EPIC participants engaged in walking, while less than 50% of the subjects participated in sport. Total time dedicated to recreational activities was highest among the Dutch participants and lowest among men from Malmö (Sweden) and women from Naples (Italy). In all centres, total time dedicated to recreational activity in the summer was higher than in the winter. Women from southern Europe spent the most time on housekeeping.

CONCLUSIONS

There is a considerable variation of physical activity across EPIC centres. This variation was especially evident for recreational activities in both men and women.

Recent weight changes and weight cycling as predictors of subsequent two year weight change in a middle-aged cohort

OBJECTIVE

To evaluate the influence of recent weight changes (weight gain, loss and cycling) on subsequent weight changes.

DESIGN

Prospective cohort study with 2 y of follow-up. Data analysis with a polytomous logistic regression model.

SUBJECTS

A total of 18 001 non-smoking subjects, 6689 men and 11 312 women, from the general population.

MEASUREMENTS

Body height and weight measurements and interview data on lifestyle habits and medical history at baseline. For follow-up, self-administered questionnaires for assessment of body weight and incident diseases.

RESULTS

Recent changes in body weight, that is weight gain, weight loss and weight cycling, were significant predictors of subsequent weight changes in both men and women after controlling for age, baseline BMI and several lifestyle and behavioural characteristics as potential confounding factors. Weight cycling before baseline was the strongest predictor of subsequent large weight gain (> or =2 kg) with an odds ratio (OR) of 4.84 (95% confidence interval (CI) 3.34-7.02) in men. In women, prior weight loss was the strongest predictor of subsequent large weight gain (OR 4.77; 95% CI 3.63-6.03), followed by weight cycling (OR 3.02; 95% CI 2.15-4.25).

CONCLUSION

These data indicate the need for thorough weight history assessment to identify those who are most likely to gain weight. Effective weight control before the development of obesity or after intentional weight loss due to obesity should be a primary goal in the management of obesity.

Assignment to menopausal status and estimation of age at menopause for women with missing or invalid data--a probabilistic approach with weighting factors in a large-scale epidemiological study

OBJECTIVE

Gynaecologic surgeries and hormone medication increasingly interfere with the concept of determining menopausal status based on self-reported data about the last menstrual period-an approach frequently applied in epidemiological studies. This analysis compared different approaches of menopausal status determination, including a probabilistic approach that was developed to reduce misclassification of menopausal status.

METHODS

Interview and questionnaire data relating to hormone status from about 16,000 German women were used to determine menopausal status using different approaches: menses based, age based, self-assessment based, and a probabilistic approach.

RESULTS

Applying strict menses-based criteria, 29.1% of the women were found to be with undetermined menopausal status. The probabilistic approach was applied to determine menopausal status and age at menopause for these women. The proposed approach uses the current age of the women with undetermined menopausal status, and the relative age-dependent frequencies of pre- or postmenopausal status among those with natural menopausal status to calculate weighting factors, which represent the probabilities of being pre- and postmenopausal of each woman previously undetermined. Correspondingly, the missing age at menopause was estimated with the same probabilistic approach. Applying various approaches to determine menopausal status, the ratio of pre- to postmenopausal women differed considerably, ranging from 1.03 to 1.61. In addition, considerable differences were observed with respect to the number of missing values for both menopausal status and age at menopause.

CONCLUSION

The probabilistic approach allowed to estimate menopausal status and age at menopause with the advantage that all available information from the entire study population and from the individual is used.

Differences of blood pressure estimates between consecutive measurements on one occasion: implications for inter-study comparability of epidemiologic studies

Currently, substantial variation in epidemiologic studies exists regarding the number of blood pressure (BP) readings obtained and the way in which they are combined. This might result in systematically different BP estimates. We therefore analysed data from 25,891 subjects (10,124 men and 15,767 women) of the EPIC-Potsdam Study (European Prospective Investigation into Cancer and Nutrition) to estimate the magnitude of differences between consecutive BP readings and their combinations. Three measurements with 2 min intervals were performed in the sitting position on the right arm with the supported arm elevated at heart level by trained interviewers using oscillometric devices. Mean BP declined from first to second reading and further to third reading by systolic 5.0/0.9 mmHg in men and 4.9/0.8 mmHg in women and by diastolic 1.5/0.3 mmHg in men and 1.9/0.5 mmHg in women, as well as pulse pressure (PP) (3.5/0.6 in men, 3.0/0.3 in women) and hypertension prevalence (9.1/1.7%-points). The magnitude of BP decline depended on BP level, age, body mass index (BMI), and BP medication. Combinations including the first reading lead to generally higher estimates than subsequent readings or their combination. Published data on mean BP, PP and hypertension prevalence depend on the number and subsequent handling of BP readings which might introduce bias to the comparison of different studies unless the same defined readings were used. The combination of the second and third reading seems to be favourable over any single reading or other combinations.

[Data protection--an obstacle for prospective studies? Solutions exemplified by a cohort study]

Prospective studies require the storage of the participants' personal data for follow-up. This demands special precautions for the protection of these data. Additional to the informed consent of the participant which enables the researchers to collect the prospective study data, the participant's right of informal self-determination should be protected. In the EPIC (European Prospective Investigation into Cancer and Nutrition) Potsdam study, therefore, an internal trustee was established that collects follow-up information from participants, physicians, clinics, health offices, tumour and population registries with the aim to obtain valid information on vital status and diseases of the participants. The internal trustee is a spatial and organizational separated working group. The isolated electronic data processing network, the alarm system which controls the rooms of the working group, the access control for employees are special security arrangements. During follow-up the individual identification number of the study data base is replaced by a specific identification number solely for the follow-up. Further, unique identification numbers are allocated to every single action and every single document such as inquiry forms which are sent to physicians, health offices, or population registries, that allow anonymous mailing and processing of the collected information. On copies of important documents, the name is erased and replaced by a specific record number. The inquiry forms for the physicians, for instance, contain the name of the participant at the head which has to be cut off before returning the form to the internal trustee. The identification number is also printed as bar code on each document facilitating its processing with technical aids such as scanners. If checkbacks are necessary, only certain work group members are able to reconnect the document number with the name. Depending on the task, the computer programmes confine automatically the details presented to the assistant. All arrangements to protect personal data do not interfere with research interests; on the contrary they lead to an efficient work routine and guarantee follow-up according to international rules.

Influence of body composition on quantitative ultrasound parameters of the os calcis in a population-based sample of pre- and postmenopausal women

Body mass is known to be related to measures of bone mineral density (BMD) as well as to parameters of quantitative ultrasound (US). To examine the effect of the body compartment's fat mass and lean body mass on quantitative ultrasonic bone parameters, data from a sample of 3241 German women were analyzed. Anthropometric measures, including skinfold thickness, were obtained from standardized measurements, and fat and lean body mass were derived from classical regression formulas based on skinfold measurements. Ultrasonic bone measurements were performed on the right os calcis, and speed of sound (SOS) and broadband ultrasound attenuation (BUA) were determined. Women were grouped into pre- and postmenopausal status; postmenopausal women were further stratified into ever and never hormone-replacement user. Correlation analysis indicated lean body mass to be stronger correlated with BUA than fat mass in both pre- (r = 0.23; P = 0.0001) and postmenopausal women with (r = 0.19; P = 0.0001) and without hormone replacement therapy (HRT) (r = 0.26; p = 0.0001). SOS demonstrated very small or no associations with body mass or its components. Multiple linear regression models were used to describe the relationship among body weight, fat mass, and lean body mass on BUA after adjustment for confounding variables. Both in pre- and postmenopausal women lean body mass was more strongly related to BUA than fat mass. However, body mass measures explained only small amounts of the overall variance in BUA (R(2) = 1-3% in premenopausal women; R(2) = 1% postmenopausal with HRT; R(2) = 4-5% in postmenopausal women without HRT). In conclusion, the strong influence of body mass and its components previously reported for BMD was not observed for quantitative ultrasonic bone parameters.

Measures of quality control in the German component of the EPIC study. European Prospective Investigation into Cancer and Nutrition

Quality control is an indispensable part of quality assurance in any study, intending to ensure high standards during data acquisition. The aim of this paper is to describe the measures of quality control undertaken in the German EPIC study centers and to present selected results of these procedures (EPIC = European Prospective Investigation into Cancer and Nutrition). For all data assessment tools applied in the German EPIC study, procedures were developed to monitor both the personnel as well as the technical instruments. These procedures combined quantitative and qualitative measurements of quality control. Interviewer performance was evaluated through direct observation and rated according to an evaluation score. Blood pressure and anthropometric measurements were both controlled through direct observation of measurement procedures as well as through periodical technical control of measurement devices. Blood sampling procedures were directly monitored and subsequent handling of the probes tightly recorded, including information on time sequence of work-up and room temperature. With these diverse control measurements and the obtained rating of assessment procedures a broad pool of information has been made available to support a critical evaluation of the data obtained in the EPIC study centers in Heidelberg and Potsdam.

Recruitment procedures of EPIC-Germany. European Investigation into Cancer and Nutrition

EPIC is among the largest cohort studies, with approximately 475,000 study participants, on the etiological influence of diet and chronic diseases. During a 4-year recruitment period, two German EPIC centers, located in Heidelberg and Potsdam, aimed to recruit a total of 60,000 study participants from the local populations. The recruitment process was based on addresses from general population registries and started 4-5 weeks in advance with an initial invitation by mail to the basic examination for this study. Subjects not responding within 2 weeks were reminded. In Potsdam, this was done by mail and telephone, and in Heidelberg by telephone. During the recruitment phase, from 1994 to 1998, 53,162 subjects in total were examined for the cohort studies in Heidelberg (n = 25,546) and Potsdam (n = 27,616). The participation rate, compared to the invited number of subjects, was 22.7% in Potsdam and 38.3% in Heidelberg, with a considerable variation by municipality and gender. A comparison with data from the National Health Survey 1991/1992 revealed that the cohort populations were of higher socio-economic status and were healthier than the source population. We concluded that the selective participation would help to ensure high maintenance of the cohort during active follow-up. Selective participation does not harm etiological conclusions because disease associations are derived internally as relative risk. The relative risk estimates can be used to calculate population-attributable risk and preventable proportion, based on exposure prevalence derived by surveys and other studies.

Follow-up procedures in EPIC-Germany--data quality aspects. European Prospective Investigation into Cancer and Nutrition

With 475,000 participants throughout Europe, EPIC is one of the largest cohort studies investigating the association between diet and cancer and other chronic diseases. The German part of EPIC comprises about 53,000 participants in Potsdam (n = 27,616) and in Heidelberg (n = 25,546). In the German study centers, follow-up started in 1998 and will be continued in 2-year intervals over the next 10-15 years. To ensure high follow-up data quality at an European level, an international working group developed guidelines for endpoint data collection in every country. A follow-up phase in Germany comprises mailing of a questionnaire, tracing of individuals to whom mail could not be delivered, obtaining information on deceased participants including cause of death, and verifying self- reported diagnoses. Furthermore, activities aimed at motivating study participants are part of the follow-up. The first round of follow-up of those who entered the study in 1994 and 1995 included 8, 706 participants in Potsdam and 6,289 in Heidelberg. Due to a comprehensive and intensive reminder and tracing system, vital status of the study subjects is known from almost 100% in Potsdam and 99% in Heidelberg. Two years after baseline examination, and with twice as many addresses in Potsdam as in Heidelberg, addresses had to be traced or checked via population registry (13 versus 6%). Tracing, the application of different mailing strategies, and intensive reminder activities resulted in a 95% return of the questionnaire in Potsdam and 90% in Heidelberg. The system of follow-up data entry and control, including completion of missing information via telephone, verification of self-reports and causes of death, has been set up for EPIC-Germany and works efficiently and successfully. The aim of this paper is to describe the follow-up procedures in EPIC-Germany with a focus on the generation of valid and complete outcome data.

Validity of self-reported diagnoses leading to hospitalization: a comparison of self-reports with hospital records in a prospective study of American adults

The authors compared interview reports with hospitalization records of participants in a nationally representative survey to determine the accuracy of self-reports of ischemic heart disease, stroke, gallbladder disease, ulcers, cataract, hip fracture, colon polyps, and cancers of the colon, breast, prostate, and lung. The study cohort consisted of 10,523 participants from the First National Health and Nutrition Examination Survey in 1971-1975 who were aged 25-74 years at the baseline examination and who completed a follow-up interview in 1982-1984. Self-reports of hospitalization for breast cancer were confirmed as accurate for 100% of cases where a hospital record was available. Self-report accuracy was also high for ischemic heart disease (84%), cataract (83%), and hip fracture (81%); it was moderate for lung cancer (78%), prostate cancer (75%), gallbladder disease (74%), colon cancer (71%), and stroke (67%); but it was low for ulcers (54%) and colon polyps (32%). Some of the self-reports of ulcers (20%), hip fracture (9%), ischemic heart disease (7%), and stroke (7%) were found to reflect diagnoses of other conditions of anatomic proximity. Accuracy of self-reports improved with higher levels of education, but was not generally related to age, gender, race, alcohol use, or smoking. The results suggest that self-reports of some diseases can be taken as accurate, but self-reports of other conditions might require medical record verification in epidemiologic follow-up studies.

Validity of self-reported cancers in a prospective cohort study in comparison with data from state cancer registries

The accuracy of self-reported cancer diagnoses in a prospective study was compared with population-based cancer registry data in four states. The study cohort included 65,582 men and women aged 39-96 years who were participants in the Cancer Prevention Study II Nutrition Survey, begun by the American Cancer Society in 1992. Estimates of sensitivity (the proportion of study participants with a registry-documented cancer who self-reported the cancer) ranged from 0.79 for an exact match of cancer site and year of diagnosis (+/- 1 year) to 0.93 for a match of any reported cancer. The sensitivity of exact matches varied considerably by cancer site and was highest for breast, prostate, and lung cancers (0.91, 0.90, and 0.90, respectively) and lowest for rectal cancer and melanoma (0.16 and 0.53, respectively). Sensitivity also varied slightly by the age, education, and smoking status of study participants. Estimates of sensitivity were virtually identical for each of the four states. The positive predictive value (the proportion of self-reported cancers that were confirmed by the registries) was 0.75 overall and also varied by cancer site. Unlike sensitivity, however, this proportion varied considerably by state. All self-reports of cancer that were not confirmed by the registries were further investigated by repeat questionnaires and acquisition of medical records. Low positive predictive values were due to underascertainment of true cancer cases by the registries, inaccurate reporting on the part of study participants, and problems with the algorithm used by the state to link the study population to the registry data. In conclusion, the ability of members of this cohort to report a past diagnosis of cancer accurately is quite high, especially for cancers of the breast, prostate, lung, and colon, or for the occurrence of any cancer.

Energy intake and net weight gain in pregnant women according to body mass index (BMI) status

OBJECTIVE

To investigate whether body mass index (BMI) is related to energy intake during pregnancy, and whether BMI, energy intake and other factors are related to net weight gain.

DESIGN

Longitudinal, duration of pregnancy.

SUBJECTS

156 healthy pregnant women residing in Quedlinburg county, Germany.

METHODS

Weighed 7 d food records and standardized anthropometric measures in the first, second and third trimester. The analysis of variance (ANOVA) statistical technique was used to analyze differences in energy intake, net weight gain and birthweight across BMI groups, and the Cochran-Mantel Haenszel test was used to analyze food group intake by BMI group.

RESULTS

Women at the highest level of BMI were significantly less often in the high energy intake category than women at the medium or low level of BMI (15% vs 36% and 48%). Net weight gain during pregnancy was independently influenced by BMI status and energy intake. Women at the highest level of BMI gained significantly less weight (4.2 kg) from first to third trimester than women at the medium or low levels of BMI (weight gains of 6.2 kg and 5.9 kg, respectively). Women with a low daily energy intake gained 4.6 kg during pregnancy, while women with medium and high energy intakes gained 6.0 kg and 6.1 kg, respectively. Examination of net weight gain simultaneously across BMI and parity groups revealed a much lower net weight gain among multigravid women at the highest BMI level (3.3 kg). Primigravid high BMI women, in contrast, gained 6.9 kg, whereas multigravid and primigravid women at medium and low BMI levels gained average of 4.8 kg and 6.5 kg, respectively. The mean birth weight in the three BMI groups did not differ and was not influenced by age, marital status, education, parity or smoking.

CONCLUSION

Because other studies have shown that weight gain during pregnancy increases the risk of subsequent overweight, multigravid high BMI women may prevent an increased weight retention after pregnancy due to lower weight gain in the current gestation. A lower caloric diet may help to accomplish a lower weight gain during pregnancy in overweight women without increased risk of low birth weight infants. These findings indicate further investigation of the associations between BMI, parity and caloric intake during pregnancy are needed to increase understanding of factors affecting subsequent weight gain.