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Nikolaus Becker

Publications and source records attributed to Nikolaus Becker.

25 records · Page 2Linked to original sources
PubMed2003

Trends in cigarette smoking in the German centers of the European Prospective Investigation into Cancer and Nutrition (EPIC): the influence of the educational level.

BACKGROUND: Several studies in Germany and other European countries have already shown smoking prevalence to be related to education. This study was aimed to investigate time trends in smoking habits in the German cohorts Heidelberg and Potsdam of the European Prospective Investigation into Cancer and Nutrition (EPIC) according to sex, birth cohort, and level of education. METHODS: Within EPIC, 25,546 and 27,548 participants were recruited in Heidelberg and Potsdam, respectively. Data on smoking were collected by means of a computer-guided interview during the baseline examination between 1994 and 1998. For each birth cohort smoking prevalence and mean number of cigarettes smoked per day at different ages were calculated. Odds ratios and 95% confidence interval for associations between smoking prevalence and educational level were computed by using logistic regression. RESULTS: Smoking prevalence was higher among men than among women, with a smaller difference in younger birth cohorts. Between 1950 and 1960, smoking prevalence among women in the Heidelberg cohort rose sharply (from 12.8% to 51.8% in the least educated group). This strong increase was delayed by 10 years in the Potsdam cohort. Men and women in Heidelberg smoked more cigarettes per day than their counterparts in Potsdam, but in both study centers less educated subjects smoked more than subjects with a higher education. CONCLUSIONS: Smoking patterns in the Potsdam and Heidelberg cohorts are quite similar with respect to prevalence and years of lifetime smoking. Since an increasing difference between smoking prevalence of less and high educated individuals is observable, programs on smoking cessation should especially concentrate on persons of lower educational level.

Adult↗
PubMed2003

Randomized trial with fruits and vegetables in prevention of cancer.

Along with tobacco use, diet has the greatest impact on the development of human cancer. Within the broad category 'diet', the consumption of fruits and vegetables apparently plays a dominant role. Considerable efforts have been made to prove the preventive effect of different kinds of fruits and vegetables but randomized chemoprevention trials have failed to prove this presumed effectiveness of their single ingredients. The conclusive demonstration of a cancer-protective effect of a high consumption of fruits and vegetables is considered to be impractical. However, current historical changes in Europe offer a unique opportunity to conduct such a randomized trial in specific European countries. This study describes the nutritional situation and the conditions of the health system in the Baltic countries as appropriate geographic areas and demonstrates some basic design issues of the trial for three variants of outcome assumptions. A realistic assumption would be that a trial needs about 30000 participants, an intervention period of 10 years and a subsequent follow-up time of 20 years. Annual costs could range between dollars 5 and dollars 10 million. A high intake of fruits and vegetables should be proven scientifically as a valid tool for cancer prevention. For a comparably short period the Baltic countries offer a time-window for a randomized trial. It is unlikely that the costs of such a trial would considerably exceed the costs of the available chemoprevention trials.

Baltic States↗
PubMed2002

Polymorphisms in candidate obesity genes and their interaction with dietary intake of n-6 polyunsaturated fatty acids affect obesity risk in a sub-sample of the EPIC-Heidelberg cohort.

BACKGROUND/AIM: In several genes coding for molecules involved in the regulation of body weight (fat mass) and thermogenesis, polymorphisms have been reported which possibly modify human obesity risk. The aim of this study was a) to reproduce these observations with data and biological material from the Heidelberg cohort of EPIC, a large European prospective investigation into diet and cancer, and b) to investigate potential effects of interactions between dietary fatty acid intake and allelic variants on obesity risk. SUBJECTS AND METHODS: Within EPIC-Heidelberg, 154 subjects with a body mass index > 35 kg/m(2) and 154 age- and sex-matched normal-weight controls were selected and genotypes determined for 11 candidate genes. Dietary intake was assessed by a validated food frequency questionnaire. Odds ratios (OR) were computed by means of unconditional logistic regression and different adjustment models. Genotyping was performed by PCR-RFLP and allele-specific PCR. RESULTS: For most of the investigated genes (PPARA, PPARG2, UCP1, UCP2, UCP3, BAR-2, APM1, leptin, SORBS1, HSL, and TNFA) an indication for a minor effect on obesity risk was found. Indication of a risk-increasing effect was strongest for the homozygous form of leptin -2548AA with an adjusted OR of 3.53 (p < 0.009). Additionally, for the polymorphic sites of BAR-2 (Arg16Gly and Gln27Glu) a significant effect on obesity risk was seen. Importantly, the results of the analysis of gene-diet interactions suggest that the allelic variants of candidate genes (leptin, TNFA, PPARG2) might strongly affect diet-related obesity risk. CONCLUSIONS: The results support some but not all previous reports about a risk-modulating effect of polymorphisms in genes affecting obesity risk. The most important finding is an indication of substantial interaction between allelic variants of particular genes and fatty acid intake-related obesity risk. These observations suggest that future studies on polymorphisms in obesity genes should take data on dietary habits into account.

Adult↗
PubMed2002

Development of a short questionnaire to assess the dietary intake of heterocyclic aromatic amines.

OBJECTIVE: Development and validation of a short instrument to assess the dietary intake of heterocyclic aromatic amines (HCA). DESIGN: At first, a longer instrument asking for the consumption of 11 meat and fish items and different preparation methods was developed. The degree of browning of these foods was assessed by means of photos. This questionnaire was sent to 500 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg, Germany, in June 1999. Using 385 completed questionnaires, a short questionnaire was developed covering just seven food items, which was sent to the participants again. Of these, 344 were returned within four months. Total dietary intake of HCA as well as the intake of different HCA were calculated and compared between both versions. RESULTS: Median dietary intake of total HCA was 103 ng day-1 as assessed with the short version; the intakes of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx) were 63, 34 and 2 ng day-1, respectively. These results did not differ significantly from those obtained with the longer version. Spearman rank correlation coefficients between the long and the short version ranged from 0.46 to 0.6. In quartile cross-classification, 70-78% of the participants were assigned into the same or an adjacent quartile while categorisation into opposite quartiles was < or =3.5%. CONCLUSION: The short version of the HCA questionnaire demonstrates good validity compared with the longer version. The intake of HCA as assessed with the short questionnaire is comparable to that found in other studies using a short questionnaire.

Adult↗
PubMed2002

Disease mapping of stage-specific cancer incidence data.

We propose two approaches for the spatial analysis of cancer incidence data with additional information on the stage of the disease at time of diagnosis. The two formulations are extensions of commonly used models for multicategorical response data on an ordinal scale. We include spatial and age-group effects in both formulations, which we estimate in a nonparametric smooth way. More specifically, we adopt a fully Bayesian approach based on Gaussian pairwise difference priors where additional smoothing parameters are treated as unknown as well. We argue that the methods are useful in monitoring the effectiveness of mass cancer screening and illustrate this through an application to data on cervical cancer in the former German Democratic Republic. The results suggest that there are large spatial differences in the stage proportions, which indicate spatial variability with respect to the introduction and effectiveness of Pap smear screening programs.

Biometry↗
PubMed2002

Linear regression calibration: theoretical framework and empirical results in EPIC, Germany.

Large scale dietary assessment instruments are usually based on the food frequency technique and have therefore to be tailored to the involved populations with respect to mode of application and inquired food items. In multicenter studies with different populations, the direct comparability of dietary data is therefore a challenge because each local dietary assessment tool might have its specific measurement error. Thus, for risk analysis the direct use of dietary measurements across centers requires a common reference. For example, in the European prospective cohort study EPIC (European Prospective Investigation into Cancer and Nutrition) a 24-hour recall was chosen to serve as such a reference instrument which was based on a highly standardized computer-assisted interview (EPIC-SOFT). The 24-hour recall was applied to a representative subset of EPIC participants in all centers. The theoretical framework of combining multicenter dietary information was previously published in several papers and is called linear regression calibration. It is based on a linear regression of the food frequency questionnaire to the reference. The regression coefficients describe the absolute and proportional scaling bias of the questionnaire with the 24-hour recall taken as reference. This article describes the statistical basis of the calibration approach and presents first empirical results of its application to fruit, cereals and meat consumption in EPIC Germany represented by the two EPIC centers, Heidelberg and Potsdam. It was found that fruit could be measured well by the questionnaire in both centers (lambdacirc; = 0.98 (males) and lambdacirc; = 0.95 (females) in Heidelberg, and lambdacirc; = 0.86 (males) and lambdacirc; = 0.7 (females) in Potsdam), cereals less (lambdacirc; = 0.53 (males) and lambdacirc; = 0.4 (females) in Heidelberg, and lambdacirc; = 0.53 (males) and lambdacirc; = 0.44 (females) in Potsdam), and that the assessment of meat (lambdacirc; = 0.72 (males) and lambdacirc; = 0.65 (females) in Heidelberg, and lambdacirc; = 0.49 (males) and lambdacirc; = 0.42 (females) in Potsdam) has a center-specific bias. The application of the calibration approach to the questionnaire data will change the ranking of the two centers following the data of the reference instrument, and not well-measured food items will exhibit considerably less variation compared to the original data. We conclude that calibration is a necessary step in multicenter studies. However, this exercise shows that the current statistical framework is not yet sufficiently developed for a broad application.

Adult↗