Use of Metabonomics and Body Imaging for Metabolic Health Assessment
Condition: Healthy
Study type: Observational

Summary: 
      The aim of this pilot study is to develop at Nestlé Research Center a database of metabolic
      profiles, body composition, food habits and physical activities on a large cohort of human
      volunteers. Analysis of collected data will serve to measure the variability of the data and
      to assess the potential of combining metabonomics with imaging techniques (iDXA) to monitor
      the metabolic and physiologic effects of foods.
    

Detailed description: 
      The study will be carried out at the metabolic unit of the Nestlé Research Center (Lausanne).
      A large cohort of subjects will be recruited among Nestlé employees. Body composition will be
      determined by iDXA (Dual-energy X-ray absorptiometry) and basal metabolism will be measured
      by metabonomic analysis of urine and plasma samples.

      Individual food habits and physical activities will be assessed by questionnaires.

      The clinical protocol plans also the measurement of energy expenditure (EE) by indirect
      calorimetry on a subset of twenty subjects. These EE data will be used to validate iDXA
      outcomes for resting energy expenditure.

      The volunteers can participate a second time to this study in the case they would like to
      control the evolution of their body composition and metabolism after a period of dietary
      regime or physical training. In such a case, a minimum period of two months between the
      visits is required.

      After two days of dietary restrictions, the volunteers will come in the morning at the
      metabolic unit at fasting state, for urine and blood sampling. The metabolism of some foods
      can bias the metabonomic analyses. Therefore, the consumption of alcoholic beverages, fish
      meals, liquorice, grapefruit, power drinks and bars, spices, mineral supplements, soft
      drinks, chocolate, coffee and tea limited to 2 cups per day, are not allowed during two days
      preceding the visit. In addition, the intake of pain-killers or antiinflammatory drugs is
      forbidden during the two days before the sampling of urine and blood because their metabolism
      alters the metabolic profiles of blood and urine.

      Antibiotics alter gut microflora, for which the activity represents an important contributor
      to the urinary metabolic profile. In order to preserve gut microflora-related metabolic
      information, we recommend a minimum period of one month between the end of any antibiotic
      therapy and the visit at the metabolic unit.

      On the visit day, subjects will come fasting at the metabolic unit, where they will have to:

        -  Answer some medical questions during an interview with the doctor in charge of the study

        -  Fill in two questionnaires on food habits and physical activities. A dietician of the
           CHUV will visit you at NRC to ask you for some questions relative to your food habits.
           This is to validate the new questionnaire you filled in

        -  Give a sample of urine

        -  Undergo iDXA scan (2 consecutive measures will be run at each of the two visits, in
           order to assess the intra-individual variability of the results) and measure of the
           state of hydration by bioimpedance The analysis of plasma samples is recommended to
           complete the metabonomic analysis. However, the blood sampling will be freely decided by
           each participant. The protocol plans also to perform measurements of resting energy
           expenditure by indirect calorimetry on a subset of twenty subjects.
    

Intervention name(s): Full body composition and of plasma and urine metabolites
Intervention type(s): Other
Intervention description(s): Full body composition in lean, fat and bone mass will be assessed from DXA scans.
Plasma and urine metabolites will be measured using metabolomics
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Studied population: 100-300 subjects, men and women selected out of Nestlé employees