Towards Objective Dietary Assessment in Large-scale Studies

Study Overview
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Brief Summary
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Enabling an objective measure of diet, covering individual foods as well as different dietary patterns, in large-scale studies has great potential; this would for instance improve our understanding of the role of diet in long-term disease prevention and care in people with type 2 diabetes. The overarching aim of this study is to develop a framework from which dietary intake can be assessed, both as single foods and dietary patterns, in cohort studies among people with type 2 diabetes. This study is performed to assess which collection strategy best reflects long-term dietary intake and to weigh this up against feasibility and costs in large-scale studies.

Detailed Description
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This is a 4-week observational study that will be carried out in adults with newly diagnosed type 2 diabetes living in Denmark. The aim is to recruit up to 60 participants aged 18-75. The participants will be asked to record and weight their habitual food intake on 8 days spread out within a one-month time period. They will also be asked to complete one 24-hour urine collection the day before study start and provide 7 morning spot urine samples on the subsequent mornings after filling in the food diary. At the start of the study period participants will undergo a DXA scan and have a blood sample taken. At the end of the study period a second blood sample will be drawn and a hair sample will also be collected. Incomplete 24-hour collections will be judged based on predicted 24-hour creatinine excretion from lean body mass and actual creatinine excretion being in the interval from 0.8-1.2, which corresponds to  20% on each side of the expected excretion. Participants falling outside this interval will be asked to complete a new 24-hour urine sample. As the primary aim of this study is validation, it is important that the samples provided are as complete as possible. In the one-month period between visits to the study center, a subset of volunteer participants (up to 20 participants) will be asked to consume extra portions of fermented dairy products (skyr, ymer and yogurt) 1-2 days before the spot urine sample to be able to validate markers for specific foods. All participants in the subcohort will consume each of the foods one time before a spot urine and one time be asked to abstain intake of dairy products as a control. Foods will be provided to the participants.

Official Title
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Towards Objective Dietary Assessment in Large-scale Studies

Conditions
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Diabetes Mellitus, Type 2

Intervention / Treatment
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* Other: Exposure: Plant-based diet pattern
* Other: Intervention: Fermented dairy products
* Other: Exposure: individual foods and food groups


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Newly diagnosed type 2 diabetes (within the last 5 years from study start) (self-reported) 18.5-35.0 kg/m2 BMI More than 1cm of natural hair on the head Have not dyed their hair in the previous 6 months Willing to record dietary intake up to 9 days Willing to have blood samples drawn two times Willing to collect up to two 24-hour urine samples and 7 spot urine samples at home and be able to store them in their own freezer in provided tubes and boxes throughout the one-month study Have no intention to radically change dietary and physical activity habits during the study period Owning a smartphone with internet connection Can speak and read Danish Exclusion Criteria: Pregnant or lactating women Diagnosed with any chronic or communicable diseases including liver diseases (e.g., active hepatitis B and C infections), liver cirrhosis, severe psychiatric illness or any other clinical condition that makes the subject ineligible according to the clinically responsible medical doctor (except type 2 diabetes) (self-reported). History of cancer within the past 5 years (except adequately-treated localized basal cell skin cancer or in situ uterine cervical cancer) Diagnosed with any CVD event (e.g., myocardial infarction, revascularization procedure or stroke) within the past 2 years Unintentional weight loss >20% during the last 6 months Regular intake of prescription medication (except diabetes medication, blood pressure-lowering medication, cholesterol-lowering medication, mild antidepressants or contraceptive pills) Concurrent participation in another trial Not willing to sign the Informed consent form (ICF) Not willing to comply with the all the trial procedures

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Type 2 diabetes<br>Overall study population. In addition, a subset of volunteer participants (up to 20 participants) will be asked to consume extra portions of fermented dairy products (skyr, ymer and yogurt) 1-2 days before the spot urine sample to be able to validate markers for specific foods. | Other: Exposure: Plant-based diet pattern<br>* From dietary records average intake across food groups will be calculated and a plant-based diet index score will be generated to group participants.<br>* Other names: Plant-based diet index;Other: Intervention: Fermented dairy products<br>* 1000g of the product to be consumed 1-2 days prior to spot urine sample.<br>* Other names: Commercially available skyr, ymer and yogurt;Other: Exposure: individual foods and food groups<br>* From the dietary records, average intake of specific foods or food groups will be calcualted.<br>* Other names: Foods and food groups;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of Indole-3-lactic acid in blood | Difference in beta-coefficient of the concentration of Indole-3-lactic acid (https://hmdb.ca/metabolites/HMDB0000671) in blood measured at the end of the study between those consuming fermented dairy products compared to participants not consuming fermented dairy products. A linear regression model will be used with Indole-3-lactic acid concentration as the outcome and consuming vs not consuming fermented dairy products as the exposure. Indole-3-lactic acid in blood will be analysed using an ultra-performance liquid chromatography (UPLC) system coupled to a quadrupole time-of-flight mass spectrometer (ViON QTOF, Waters Corporation, Manchester, UK). | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of Indole-3-lactic acid in urine | Difference in beta-coefficient of the concentration of Indole-3-lactic acid (https://hmdb.ca/metabolites/HMDB0000671) in the average of 7 spot urine samples between those consuming fermented dairy products compared to participants not consuming fermented dairy products. A linear regression model will be used with Indole-3-lactic acid concentration as the outcome and consuming vs not consuming fermented dairy products as the exposure. Indole-3-lactic acid in urine will be analysed using an ultra-performance liquid chromatography (UPLC) system coupled to a quadrupole time-of-flight mass spectrometer (ViON QTOF, Waters Corporation, Manchester, UK). | 1 month | 
| Concentration of 3-Phenyllactic acid in blood | Difference in beta-coefficient of the concentration of 3-Phenyllactic acid (https://hmdb.ca/metabolites/HMDB0000779) in blood measured at the end of the study between those consuming fermented dairy products compared to participants not consuming fermented dairy products. A linear regression model will be used with 3-Phenyllactic acid concentration as the outcome and consuming vs not consuming fermented dairy products as the exposure. Indole-3-lactic acid in blood will be analysed using an ultra-performance liquid chromatography (UPLC) system coupled to a quadrupole time-of-flight mass spectrometer (ViON QTOF, Waters Corporation, Manchester, UK). | 1 month | 
| Concentration of 3-Phenyllactic acid in urine | Difference in beta-coefficient of the concentration of 3-Phenyllactic acid (https://hmdb.ca/metabolites/HMDB0000779) in the average of 7 spot urine samples between those consuming fermented dairy products compared to participants not consuming fermented dairy products. A linear regression model will be used with 3-Phenyllactic acid concentration as the outcome and consuming vs not consuming fermented dairy products as the exposure. Indole-3-lactic acid in urine will be analysed using an ultra-performance liquid chromatography (UPLC) system coupled to a quadrupole time-of-flight mass spectrometer (ViON QTOF, Waters Corporation, Manchester, UK). | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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sampling, food intake biomarkers, type 2 diabetes, urine, blood, hair, diet assessment