title: Application of a new statistical method to derive dietary patterns in nutritional epidemiology.
abstract: Because foods are consumed in combination, it is difficult in observational studies to separate the effects of single foods on the development of diseases. A possible way to examine the combined effect of food intakes is to derive dietary patterns by using appropriate statistical methods. The objective of this study was to apply a new statistical method, reduced rank regression (RRR), that is more flexible and powerful than the classic principal component analysis. RRR can be used efficiently in nutritional epidemiology by choosing disease-specific response variables and determining combinations of food intake that explain as much response variation as possible. The authors applied RRR to extract dietary patterns from 49 food groups, specifying four diabetes-related nutrients and nutrient ratios as responses. Data were derived from a nested German case-control study within the European Prospective Investigation into Cancer and Nutrition-Potsdam study consisting of 193 cases with incident type 2 diabetes identified until 2001 and 385 controls. The four factors extracted by RRR explained 93.1% of response variation, whereas the first four factors obtained by principal component analysis accounted for only 41.9%. In contrast to principal component analysis and other methods, the new RRR method extracted a significant risk factor for diabetes.
authors.affiliation: Department of Epidemiology, German Institute of Human Nutrition, Bergholz-Rehbrücke, Germany. khoff@mail.dife.de
authors.forename: Kurt
authors.initials: K
authors.lastname: Hoffmann
authors.forename: Matthias B
authors.initials: MB
authors.lastname: Schulze
authors.forename: Anja
authors.initials: A
authors.lastname: Schienkiewitz
authors.forename: Ute
authors.initials: U
authors.lastname: Nöthlings
authors.forename: Heiner
authors.initials: H
authors.lastname: Boeing
mesh_terms: D000428:Alcohol Drinking / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D015340:Epidemiologic Research Design; D005247:Feeding Behavior; D005858:Germany / Q000453:epidemiology; D006801:Humans; D016018:Least-Squares Analysis; D008274:Magnesium / Q000008:administration & dosage; D015233:Models, Statistical; D015337:Multicenter Studies as Topic / Q000379:methods; D009749:Nutrition Surveys; D025341:Principal Component Analysis / Q000379:methods; D012044:Regression Analysis; D018570:Risk Assessment
chemical_list: D004041:Dietary Fats; D004043:Dietary Fiber; D008274:Magnesium