Lactose and Lipids

Study Overview
=================
Brief Summary
-----------------
This study aims to determine to what extent ingestion of free sugars influence postprandial triglyceridaemia in men and women.

Detailed Description
-----------------
Each participant will undergo three experimental trials in a randomized, crossover research design. On each study day, participants will consume a test drink containing standardised amounts of carbohydrate and fat followed by collection of blood and breath samples to assess metabolic responses during the 6 hour postprandial period. Trials will be identical except for the type of carbohydrate contained within the test drink: 1) maltodextrin (glucose polymer), 2) lactose (galactose-glucose disaccharide) and 3) sucrose (fructose-glucose disaccharide).

Official Title
-----------------
Revealing the Mechanisms by Which Milk Sugars Exaggerate Postprandial Lipaemia

Conditions
-----------------
Cardiovascular Risk Factor, Lipaemia, Metabolic Disease

Intervention / Treatment
-----------------
* Dietary Supplement: Maltodextrin
* Dietary Supplement: Sucrose
* Dietary Supplement: Lactose


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: • Age: 18-50 years and premenopausal (for women) Exclusion criteria: Weight instability (>5 kg change in body mass within last 6 months) Diagnosis of any form of diabetes Intolerances or allergies to any of the study procedures (e.g. lactose intolerance) Galactose disorders (e.g. galactokinase deficiency, UDPgalactose-4-epimerase deficiency, galactose-1-phosphate uridyl transferase deficiency) Fructose malabsorption Inborn errors of fructose metabolism (e.g. fructokinase deficiency, aldolase B deficiency, fructose-1,6-bisphosphatase deficiency) Pregnant or lactating Any condition that could introduce bias to the study (e.g. diagnoses of lipid disorders, including cardiovascular disease, or therapies that alter lipid or glucose metabolism, such as statins or niacin).

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Maltodextrin<br>Glucose polymer; a common sugar substitute | Dietary Supplement: Maltodextrin<br>* Co-ingestion of maltodextrin with a high fat meal<br>|
| Active Comparator: Sucrose<br>Fructose-glucose disaccharide | Dietary Supplement: Sucrose<br>* Co-ingestion of sucrose with a high fat meal<br>|
| Experimental: Lactose<br>Galactose-glucose disaccharide | Dietary Supplement: Lactose<br>* Co-ingestion of lactose with a high fat meal<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial changes in plasma triglyceride concentrations | Incremental area under the curve (iAUC) of plasma triglyceride concentrations | 6 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial de novo lipogenesis (DNL) | Time course for synthesis of fatty acids from non-lipid precursors using stable isotope methodology | 6 hours | 
| Dietary fat oxidation | Time course for whole-body dietary fatty acid oxidation using stable isotope methodology | 6 hours | 
| Postprandial changes in plasma insulin concentrations | Incremental area under the curve (iAUC) of plasma insulin concentrations | 6 hours | 
| Postprandial changes in plasma glucose concentrations | Incremental area under the curve (iAUC) of plasma glucose concentrations | 6 hours | 
| Postprandial changes in plasma galactose concentrations | Incremental area under the curve (iAUC) of plasma galactose concentrations | 6 hours | 
| Postprandial changes in plasma fructose concentrations | Incremental area under the curve (iAUC) of plasma fructose concentrations | 6 hours | 
| Postprandial changes in plasma VLDL-rich triglyceride [Svedberg flotation rate (Sf): 20-400] concentrations | Incremental area under the curve (iAUC) of plasma VLDL-rich triglyceride [Svedberg flotation rate (Sf): 20-400] concentrations | 6 hours | 
| Postprandial changes in plasma chylomicron-rich triglyceride (Sf: >400) concentrations | Incremental area under the curve (iAUC) of plasma chylomicron-rich triglyceride (Sf: >400) concentrations | 6 hours | 
| Postprandial changes in plasma lactate concentrations | Incremental area under the curve (iAUC) of plasma lactate concentrations | 6 hours | 
| Postprandial changes in plasma non-esterified fatty acid concentrations | Incremental area under the curve (iAUC) of plasma non-esterified fatty acid concentrations | 6 hours | 
| Postprandial changes in plasma beta-hydroxybutyrate concentrations | Incremental area under the curve (iAUC) of plasma beta-hydroxybutyrate concentrations | 6 hours | 
| Postprandial changes in plasma uric acid concentrations | Incremental area under the curve (iAUC) of plasma uric acid concentrations | 6 hours |