The reproducibility of a diet using three different dietary standardisation techniques in athletes.

BACKGROUND/OBJECTIVES: Participants are often asked to replicate their diet before each trial to control dietary intake. However, little is known about the reproducibility of the diet using different approaches. The aim was to assess the reproducibility of a diet when a controlled diet (Cdiet), food record (Frecord) and 24-h dietary recall (Drecall) were used as dietary standardisation techniques. SUBJECTS/METHODS: Thirty athletes completed six visits to the laboratory. On the first occasion, a Drecall was performed and subjects were asked to replicate exactly the same diet on the day before visit 2, when another Drecall was performed. The day before the third visit, subjects completed a Frecord, which was presented at visit 3 and assessed using Drecall to ensure comparability between methods. Subjects were asked to replicate this Frecord before visit 4, which was assessed using Drecall. Finally, subjects were provided with a Cdiet of known composition, which they consumed for 24 h before visits 5 and 6. For each method, the difference in energy and macronutrient intakes between both occasions was measured. RESULTS: Despite finding no differences in mean energy and macronutrient intakes between visits for any technique, important within-subject differences were apparent. The range of percentage coefficient of variation for all variables was between 2.7 and 5.8% for Cdiet, 10.1 and 18.6% for Frecord and 7.1 and 11.7% for Drecall. CONCLUSIONS: This study has shown that Cdiet is the best approach to standardise dietary intake, especially when the expected effect of an intervention is small and an enhanced reliability is required.

[Familial prostate carcinoma in Germany]. / Das familiäre Prostatakarzinom in Deutschland.

Epidemiologic studies have shown that hereditary forms account for approximately 10% of all prostate cancers. The identification of several susceptibility loci harboring predisposing genes indicates the genetic heterogeneity of prostate cancer. The conflicting results of different linkage analyses may be explained by a varying contribution of each locus within different family collections and reflect differences of allele frequencies across different populations. In the present study we recorded the incidence of familial prostate cancer in Germany and performed descriptive analysis of the epidemiological data. In spite of a significant ascertainment bias, only 19% of all prostate cancers were familial. In 94% of families there were three affected relatives at most. Large prostate cancer families with at least five affected persons were rare (2%). Descriptive analysis revealed that only 42% of all pedigrees followed an autosomal-dominant pattern of transmission; the other pedigrees showed an X-chromosomal or recessive mode of inheritance. These data confirm the genetic heterogeneity of hereditary prostate cancer and imply that previously published epidemiological data cannot be transferred to the German population.