Search PubMed⌕ Search

Biomedical subjects

Kurt Hoffmann

Publications and source records attributed to Kurt Hoffmann.

At least 19 recordsLinked to original sources
PubMed2006

Intake of fruits and vegetables and risk of cancer of the upper aero-digestive tract: the prospective EPIC-study.

Epidemiologic studies suggest that a high intake of fruits and vegetables is associated with decreased risk of cancers of the upper aero-digestive tract. We studied data from 345,904 subjects of the prospective European Investigation into Cancer and Nutrition (EPIC) recruited in seven European countries, who had completed a dietary questionnaire in 1992-1998. During 2,182,560 person years of observation 352 histologically verified incident squamous cell cancer (SCC) cases (255 males; 97 females) of the oral cavity, pharynx, larynx, and esophagus were identified. Linear and restricted cubic spline Cox regressions were fitted on variables of intake of fruits and vegetables and adjusted for potential confounders. We observed a significant inverse association with combined total fruits and vegetables intake (estimated relative risk (RR) = 0.91; 95% confidence interval (95% CI) 0.83-1.00 per 80 g/d of consumption), and nearly significant inverse associations in separate analyses with total fruits and total vegetables intake (RR: 0.97 (95% CI: 0.92-1.02) and RR = 0.89 (95% CI: 0.78-1.02) per 40 g/d of consumption). Overall, vegetable subgroups were not related to risk with the exception of intake of root vegetables in men. Restricted cubic spline regression did not improve the linear model fits except for total fruits and vegetables and total fruits with a significant decrease in risk at low intake levels (<120 g/d) for fruits. Dietary recommendations should consider the potential benefit of increasing fruits and vegetables consumption for reducing the risk of cancers of the upper aero-digestive tract, particularly at low intake.

Carcinoma, Squamous Cell↗
PubMed2006

Interleukin-6 g.-174G>C promoter polymorphism is associated with obesity in the EPIC-Potsdam Study.

Homozygosity for the interleukin-6 (IL-6) g.-174G>C promoter polymorphism has recently been associated with indices of overweight. Homozygous subjects were observed to have reduced energy expenditure, suggesting that lower IL-6 gene transcription, caused by the IL-6 g.-174G>C promoter polymorphism, may be associated with obesity. The aim of this study was to investigate the association of this polymorphism with long-term weight gain. For 334 normal weight (20 < BMI < or = 25 kg/m2) and 334 obese (BMI > 30 kg/m2) subjects matched by age and sex originating from the population-based EPIC-Potsdam Study, recalled weight change from age 25 to study enrollment was determined, the IL-6 g.-174G>C promoter polymorphism was defined, and plasma concentrations of IL-6 and C-reactive protein were measured. The IL-6 g.-174G>C promoter polymorphism was significantly associated with obesity (chi2 = 7,34, p = 0.026). Odds ratios for subjects with GC and CC genotypes for obesity were 1.19 (95% CI: 0.84 to 1.68; p = 0.323) and 1.91 (95% CI: 1.19 to 3.08; p = 0.007), respectively. Recalled weight change from age 25 years to study enrollment differed significantly according to genotype (p = 0.044) and was most pronounced in subjects with the CC genotype, suggesting that the IL-6 g.-174G>C promoter polymorphism is a susceptibility or modifying locus for common obesity and weight gain.

Adult↗
PubMed2006

Methodological approaches to study dietary patterns in relation to risk of coronary heart disease and stroke.

Dietary pattern analysis, which reflects the complexity of dietary intake, has received considerable attention by nutritional epidemiology. For a long time, two general approaches have been used to define these summary variables in observational studies. The exploratory approach is based only on the data of the study, whereas the hypothesis-oriented approach constructs pattern variables based on scientific evidence available before the study. Recently, a new statistical method, reduced rank regression, was applied to nutritional epidemiology that is exploratory by nature, but can use scientific evidence by focusing on disease-related dietary components or biomarkers. Several studies, both observational and clinical, suggest that dietary patterns may predict the risk of CHD and stroke. In the present review, we describe the results of these studies and the available evidence regarding the relationships between dietary patterns and risk of CVD and we discuss limitations and strengths of the statistical methods used to extract dietary patterns.

Coronary Disease↗
PubMed2006

Body mass index history and risk of type 2 diabetes: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study.

BACKGROUND: Obesity and increases in body weight in adults are considered to be among the most important risk factors for type 2 diabetes. OBJECTIVE: The objective was to evaluate and compare the associations between weight changes during 2 different periods of adult life and the risk of type 2 diabetes and age at diagnosis. DESIGN: The study included 7720 men and 10 371 women from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study with information on weight history; 390 men and 303 women of these participants received a clinical diagnosis of type 2 diabetes during 7 y of follow-up. Multivariate Cox regression models were used to estimate the relative risk (RR) of weight changes between ages 25 and 40 y and ages 40 and 55 y. RESULTS: RR estimates in men and women were slightly higher for each unit of BMI gain between ages 25 and 40 y [men: 1.25 (95% CI: 1.21, 1.30); women: 1.24 (1.20, 1.27)] than between ages 40 and 55 y [men: 1.13 (1.10, 1.16); women: 1.11 (1.08, 1.14)]. Severe weight gain between ages 25 and 40 y was associated with a higher diabetes risk in men (1.5 times) and in women (4.3 times) than were stable weight in early adulthood and weight gain in later life, and it resulted in an average lower age at diabetes diagnosis in men (5 y) and in women (3 y). CONCLUSION: Weight gain in early adulthood is related to a higher risk and earlier onset of type 2 diabetes than is weight gain between 40 and 55 y of age.

Adult↗
PubMed2006

The androgen receptor CAG repeat modifies the impact of testosterone on insulin resistance in women with polycystic ovary syndrome.

OBJECTIVE: Hyperandrogenism is a central feature of the polycystic ovary syndrome (PCOS) and might worsen insulin resistance (IR) often seen in PCOS. Androgens act through the androgen receptor (AR). A polymorphic CAG repeat sequence within the AR gene was reported to modulate its transactivation activity. Therefore, we investigated a putative interaction between testosterone and the CAG repeat length polymorphism with respect to IR. DESIGN: In 63 PCOS women with normal glucose tolerance free testosterone, the biallelic CAG repeat length and a multiplicative interaction term were investigated by multiple linear regression analysis for an association with IR as indicated by the homeostasis model assessment of IR (HOMA-IR). RESULTS: Free testosterone was correlated with HOMA-IR. The impact of testosterone on HOMA-IR was modified by the AR CAG length as indicated by an interaction term. This interaction remained significant after adjustment for smoking, age and body mass index. While there was a positive association of free testosterone with HOMA-IR, the interaction term was inversely associated. The model, which explained 42.5% of the variation of HOMA-IR predicted that in carriers of short CAG lengths, an increase in testosterone increased IR. This effect attenuated with rising biallelic CAG length until it turns into the opposite at a CAG length longer than 23. The results were confirmed by using CIGMA as another measure of IR. CONCLUSIONS: The association between testosterone and IR is modified by the CAG repeat polymorphism within the AR. Therefore, the evaluation of testosterone effects on IR seems to require consideration of the AR CAG repeat polymorphism in PCOS women.

Adult↗
PubMed2005

Estimating the proportion of disease due to classes of sufficient causes.

Disease can be caused by different mechanisms. A possible causal model proposed by Rothman is a complete causal mechanism or a so-called "sufficient cause" consisting of a set of component causes that can be illustrated in a pie chart. However, this model does not allow finding out what sufficient causes produce the majority of cases. The authors' objective was to extend Rothman's work by quantifying the proportion of disease that can be attributed to a class of sufficient causes. The underlying idea was to consider all combinations of a given set of known risk factors and to assign each combination to a class of sufficient causes. This assignment makes it possible to evaluate a class of sufficient causes by the population attributable fraction of the corresponding combination of risk factors. The approach presented was applied to sufficient causes of myocardial infarction by use of data on participants recruited between 1994 and 1998 into the European Prospective Investigation into Cancer and Nutrition-Potsdam Study. As a result, 51.8% of cases were attributed to only four different classes of sufficient causes. In conclusion, the statistical method described in the paper may be beneficial for quantifying the importance of different sufficient causes and for improving the efficiency of public health programs.

Causality↗
PubMed2005

The relation between dietary protein, calcium and bone health in women: results from the EPIC-Potsdam cohort.

BACKGROUND/AIMS: The role of dietary protein in bone health is controversial. The objective of the present study was to examine the association between protein intake, dietary calcium, and bone structure measured by broadband ultrasound attenuation (BUA). METHODS: Our analysis includes 8,178 female study participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) Potsdam Study. Ultrasound bone measurements were performed on the right os calcis, and BUA was determined. Dietary intake was assessed by a standardized food frequency questionnaire. We applied linear regression models to estimate the association between dietary protein and BUA. RESULTS: After multivariate adjustment, high intake of animal protein was associated with decreased BUA values (beta = -0.03; p = 0.010) whereas high vegetable protein intake was related to an increased BUA (beta = 0.11; p = 0.007). The effect of dietary animal protein on BUA was modified by calcium intake. CONCLUSION: High consumption of protein from animal origin may be unfavourable, whereas a higher vegetable protein intake may be beneficial for bone health. Our results strengthen the hypothesis that high calcium intake combined with adequate protein intake based on a high ratio of vegetable to animal protein may be protective against osteoporosis.

Adult↗
PubMed2005

Modified Mediterranean diet and survival: EPIC-elderly prospective cohort study.

OBJECTIVE: To examine whether adherence to the modified Mediterranean diet, in which unsaturates were substituted for monounsaturates, is associated with longer life expectancy among elderly Europeans. DESIGN: Multicentre, prospective cohort study. SETTING: Nine European countries (Denmark, France, Germany, Greece, Italy, the Netherlands, Spain, Sweden, United Kingdom). PARTICIPANTS: 74,607 men and women, aged 60 or more, without coronary heart disease, stroke, or cancer at enrolment and with complete information about dietary intake and potentially confounding variables. MAIN OUTCOME MEASURES: Extent of adherence to a modified Mediterranean diet using a scoring system on a 10 point scale, and death from any cause by time of occurrence, modelled through Cox regression. RESULTS: An increase in the modified Mediterranean diet score was associated with lower overall mortality, a two unit increment corresponding to a statistically significant reduction of 8% (95% confidence interval 3% to 12%). No statistically significant evidence of heterogeneity was found among countries in the association of the score with overall mortality even though the association was stronger in Greece and Spain. When dietary exposures were calibrated across countries, the reduction in mortality was 7% (1% to 12%). CONCLUSION: The Mediterranean diet, modified so as to apply across Europe, was associated with increased survival among older people.

Aged↗
PubMed2005

Comparison of two statistical approaches to predict all-cause mortality by dietary patterns in German elderly subjects.

Dietary patterns are comprehensive variables of dietary intake appropriate to model the complex exposure in nutritional research. The objectives of this study were to identify dietary patterns by applying two statistical methods, principal component analysis (PCA) and reduced rank regression (RRR), and to assess their ability to predict all-cause mortality. Motivated by previous studies we chose percentages of energy from different macronutrients as response variables in the RRR analysis. We used data from 9356 German elderly subject enrolled in the European Prospective Investigation into Cancer and Nutrition study. The first RRR pattern, subjects which explained 30.8 % of variation in energy sources and especially much variation in intake of saturated fat, monounsaturated fat and carbohydrates was a significant predictor of all-cause mortality. The pattern score had high positive loadings in all types of meat, butter, sauces and eggs, and was inversely associated with bread and fruits. After adjustment for other known risk factors, the relative risks from the lowest to highest quintiles of the first RRR pattern score were 1.0, 1.01, 0.96, 1.32, 1.61 (P for trend: 0.0004). In contrast, the first two PCA patterns explaining 19.7 % of food intake variation but only 7.0 % of variation in energy sources were not related to mortality. These results suggest that variation in macronutrients is meaningful for mortality and that the RRR method is more appropriate than the classic PCA method to identify dietary patterns relevant to mortality.

Aged↗
PubMed2005

Dietary patterns among older Europeans: the EPIC-Elderly study.

Overall dietary patterns have been associated with health and longevity. We used principal component (PC) and cluster analyses to identify the prevailing dietary patterns of 99 744 participants, aged 60 years or older, living in nine European countries and participating in the European Prospective Investigation into Cancer and Nutrition (EPIC-Elderly cohort) and to examine their socio-demographic and lifestyle correlates. Two PC were identified: PC1 reflects a 'vegetable-based' diet with an emphasis on foods of plant origin, rice, pasta and other grain rather than on margarine, potatoes and non-alcoholic beverages. PC2 indicates a 'sweet- and fat-dominated' diet with a preference for sweets, added fat and dairy products but not meat, alcohol, bread and eggs. PC1 was associated with a younger age, a higher level of education, physical activity, a higher BMI, a lower waist:hip ratio and never and past smoking. PC2 was associated with older age, less education, never having smoked, a lower BMI and waist:hip ratio and lower levels of physical activity. Elderly individuals in southern Europe scored positively on PC1 and about zero on PC2, whereas the elderly in northern Europe scored negatively on PC1 and variably on PC2. The results of cluster analysis were compatible with the indicated dietary patterns. 'Vegetable-based' and a 'sweet- and fat-dominated' diets are prevalent among the elderly across Europe, and there is a north-south gradient regarding their dietary choices. Our study contributes to the identification of groups of elderly who are likely to have different prospects for long-term disease occurrence and survival.

Age Distribution↗
PubMed2005

Dietary pattern, inflammation, and incidence of type 2 diabetes in women.

BACKGROUND: Inflammation is considered a key mechanism leading to type 2 diabetes, but dietary exposures that lead to inflammation and diabetes are largely unknown. OBJECTIVE: Our objective was to investigate the relation between a dietary pattern associated with biomarkers of inflammation and the incidence of type 2 diabetes. DESIGN: We conducted a nested case-control study of 656 cases of type 2 diabetes and 694 controls among women in the Nurses' Health Study and 2 prospective cohort studies of 35,340 women in the Nurses' Health Study and 89,311 women in the Nurses' Health Study II who were followed for incident diabetes. RESULTS: Through the use of reduced rank regression, we identified a dietary pattern that was strongly related to inflammatory markers in the nested case-control study. This pattern, which was high in sugar-sweetened soft drinks, refined grains, diet soft drinks, and processed meat but low in wine, coffee, cruciferous vegetables, and yellow vegetables, was associated with an increased risk of diabetes (multivariate-adjusted odds ratio comparing extreme quintiles: 3.09; 95% CI: 1.99, 4.79). We identified 1517 incident cases of confirmed type 2 diabetes in the Nurses' Health Study (458,991 person-years) and 724 incident cases in the Nurses' Health Study II (701,155 person-years). After adjustment for body mass index and other potential lifestyle confounders, the relative risks comparing extreme quintiles of the pattern were 2.56 (95% CI: 2.10, 3.12; P for trend < 0.001) in the Nurses' Health Study and 2.93 (95% CI: 2.18, 3.92; P for trend < 0.001) in the Nurses' Health Study II. CONCLUSION: The dietary pattern identified may increase chronic inflammation and raise the risk of developing type 2 diabetes.

Adult↗
PubMed2005

Identification of a food pattern characterized by high-fiber and low-fat food choices associated with low prospective weight change in the EPIC-Potsdam cohort.

The aim of the study was to identify a dietary pattern predictive of subsequent annual weight change by using dietary composition information. Study subjects were 24,958 middle-aged men and women of the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort. To derive dietary patterns, we used the reduced rank regression method with 3 response variables presumed to affect weight change: fat density, carbohydrate density, and fiber density. Annual weight change was computed by fitting a linear regression line to each person's body weight data (baseline, and 2- and 4-y follow-up) and determining the slope. In linear regression models, the pattern score was related to annual weight change. We identified a food pattern of high consumption of whole-grain bread, fruits, fruit juices, grain flakes/cereals, and raw vegetables, and of low consumption of processed meat, butter, high-fat cheese, margarine, and meat to be predictive of subsequent weight change. Mean annual weight gain gradually decreased with increasing pattern score (P for trend < 0.0001), i.e., subjects scoring high for the pattern maintained their weight or gained significantly less weight over time compared with subjects with an opposite pattern. However, the prediction of annual weight change by the food pattern was significant only in nonobese subjects. In this study population, we identified a food pattern characterized by high-fiber and low-fat food choices that can help to maintain body weight or at least prevent excess body weight gain.

Body Weight↗
PubMed2005

A homocysteine metabolism-related dietary pattern and the risk of coronary heart disease in two independent German study populations.

A biomarker profile of high folate and vitamin B-12 and low plasma homocysteine concentrations reduces the risk of coronary heart disease (CHD) and may be linked to diet. The objectives of the present study were to identify a food pattern related to these biomarkers and to examine its association with CHD risk. Dietary patterns related to biomarker plasma concentrations were constructed from data obtained in the Coronary Risk Factors for Atherosclerosis in Women (CORA) Study (200 cases; 255 controls) using the reduced rank regression statistical method. Risks for CHD with relation to the identified pattern were estimated in the CORA study and in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study with 157 cases of incident myocardial infarction among 26,795 participants. In these 2 German study populations, whole-grain bread, fresh fruit, olive oil, mushrooms, cruciferous vegetables, wine, and nuts contributed the most positively and fried potatoes the most negatively to a dietary pattern that was directly associated with both plasma folate and vitamin B-12 concentrations, but inversely with plasma homocysteine. Multivariate-adjusted relative risks for CHD across increasing quintiles of the food pattern score were 1.0, 0.55, 0.52, 0.58, 0.39 (P for trend = 0.05) in the case-control sample and 1.0, 0.95, 0.75, 0.56, 0.72 (P for trend = 0.041) in the prospective study. The combination of a high intake of whole-grain bread, fresh fruit, olive oil, mushrooms, cruciferous vegetables, wine, and nuts with a low intake of fried potatoes was associated with a favorable biomarker profile of homocysteine metabolism and reduced risk of CHD.

Aged↗
PubMed2005

Fruit and vegetable consumption and risk of epithelial ovarian cancer: the European Prospective Investigation into Cancer and Nutrition.

OBJECTIVE: The association between consumption of fruit and vegetables and risk of ovarian cancer is still unclear from a prospective point of view. METHODS: Female participants (n = 325,640) of the European Prospective Investigation into Cancer and Nutrition study, free of any cancer at baseline, were followed on average for 6.3 years to develop ovarian cancer. During 2,049,346 person-years, 581 verified cases of primary, invasive epithelial ovarian cancer were accrued. Consumption of fruits and vegetables as well as subgroups of vegetables, estimated from validated dietary questionnaires and calibrated thereafter, was related to ovarian cancer incidence in multivariable hazard regression models. Histologic subtype specific analyses were done. RESULTS: Total intake of fruit and vegetables, separately or combined, as well as subgroups of vegetables (fruiting, root, leafy vegetables, cabbages) was unrelated to risk of ovarian cancer. A high intake of garlic/onion vegetables was associated with a borderline significant reduced risk of this cancer. The examination by histologic subtype indicated some differential effects of fruit and vegetable intake on ovarian cancer risk. CONCLUSION: Overall, a high intake of fruits and vegetables did not seem to protect from ovarian cancer. Garlic/onion vegetables may exert a beneficial effect. The study of the histologic subtype of the tumor warrants further investigation.

Adult↗