SREBF1 Polymorphism and Egg Yolk on Cardiovascular Disease Risk in Healthy Young Adults: a Randomised, Two-period, Single Blinded, Crossover Trial

Study Overview
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Brief Summary
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Our previous analysis showed that sterol regulatory element binding protein gene (SREBF1) rs2236513/rs2297508/rs4925119 polymorphism modulated the relation between dietary cholesterol and serum low density lipoprotein cholesterol /serum total cholesterol. This study aims to confirm and extend this finding by characterizing the effects of cholesterol from egg yolks on lipid profiles in healthy young adults with different SREBF1 genetic makeup. 32 SREBF1 C/G/G minor allele carriers at rs2236513/rs2297508/rs4925119 and 32 SREBF1 AA/CC/AA major homozygotes at rs2236513/rs2297508/rs4925119 were enrolled to test their response to egg yolks.

Official Title
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SREBF1 Polymorphism and Egg Yolk on Cardiovascular Disease Risk in Healthy Young Adults: a Randomised, Two-period, Single Blinded, Crossover Trial

Conditions
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Healthy, GEN1 Gene Mutation

Intervention / Treatment
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* Dietary Supplement: Egg yolks
* Dietary Supplement: Macronutrients equivalent control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: SREBF1 C/G/G minor allele carriers and AA/CC/AA major homozygotes at rs2236513/rs2297508/rs4925119, age 18-25 years, body mass index (BMI) 18 23.9 kg/m2 , blood pressure within normal ranges (Systolic blood pressure < 140mmHg, diastolic blood pressure < 90mmHg), lipid profiles within normal ranges according to test kit instructions (fasting serum triglycerides < 1.7mmol/L, fasting serum total cholesterol < 5.2 mmol/L, fasting serum low density lipoprotein cholesterol (LDL-C) < 3.12 mmol/L, fasting serum high density lipoprotein cholesterol (HDL-C) >1.04 mmol/L ), liver and kidney functions within normal ranges according to test kit instructions (alanine aminotransferase (ALT) 9 50 U/L for male, 7 40 U/L for female; aspartate transaminase (AST) 15 40 U/L for male, 13 35 U/L for female; creatinine 62 115 μmol/L for male, 53 97 μmol/L for female; blood urea nitrogen (BUN), 1.43 7.14 mmol/L), both parents are Chinese Han nationality, willing to eat two or more eggs, and willing to maintain Three Low Diet except when they were given egg yolks during the study. Exclusion Criteria: History of diabetes, cancer, stroke, heart disease or any other known diseases, allergic to eggs, or having habits such as drinking or smoking.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 25 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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group A<br>Group A was consisted of 16 rs2236513/rs2297508/rs4925119 C/G/G carriers and 16 AA/CC/AA homozygotes. And it was first assigned egg yolk intervention during intervention period 1, and then macronutrient equivalent control during intervention period 2 | Dietary Supplement: Egg yolks<br>* Two egg yolks/day was designed for the study. However, uneven egg sizes during period 1 made the intervention unable to achieve the protocol's recommended cholesterol intake level, and the intervention was modified in period 2 to be 0.8 g egg yolk/day/kg body weight. This dosage was calculated by dividing the 35 g egg yolk with the lightest weight among the volunteers, which was 45 kg. This provides a more consistent cholesterol intake between persons as the egg yolk dosage is standardized for persons with different weights.<br>Dietary Supplement: Macronutrients equivalent control<br>* The macronutrients equivalent control group was served 42 g egg white cooked with 10 g olive oil, designed to best imitate the energy and macronutrients of 35 g egg yolk (energy 119 kcal, protein 5 g, fat 10 g, carbohydrate 1 g) since the average weight of two large egg yolk was presumed to be 35 g. As an egg yolk dose of 0.8 g egg yolk per kg body weight per day was served during the intervention period 2, the macronutrients equivalent control was likewise adjusted as follow: subjects who weighed less than 55 kg were served 51 g egg white cooked with 12 g olive oil, which is equivalent to 40 g egg yolk; those who weighed from 55 kg to 65 kg were served 61 g egg white cooked with 14 g olive oil, which is equivalent to 48 g egg yolk; and those who weighed more than 65 kg were served 71 g egg white cooked with 17 g olive oil, which is equivalent to 56 g egg yolk.<br>|
| Other: Group B<br>Group B was also consisted of 16 rs2236513/rs2297508/rs4925119 C/G/G carriers and 16 AA/CC/AA homozygotes. It was first assigned macronutrient equivalent control during intervention period 1, and then egg yolk during intervention period 2 | Dietary Supplement: Egg yolks<br>* Two egg yolks/day was designed for the study. However, uneven egg sizes during period 1 made the intervention unable to achieve the protocol's recommended cholesterol intake level, and the intervention was modified in period 2 to be 0.8 g egg yolk/day/kg body weight. This dosage was calculated by dividing the 35 g egg yolk with the lightest weight among the volunteers, which was 45 kg. This provides a more consistent cholesterol intake between persons as the egg yolk dosage is standardized for persons with different weights.<br>Dietary Supplement: Macronutrients equivalent control<br>* The macronutrients equivalent control group was served 42 g egg white cooked with 10 g olive oil, designed to best imitate the energy and macronutrients of 35 g egg yolk (energy 119 kcal, protein 5 g, fat 10 g, carbohydrate 1 g) since the average weight of two large egg yolk was presumed to be 35 g. As an egg yolk dose of 0.8 g egg yolk per kg body weight per day was served during the intervention period 2, the macronutrients equivalent control was likewise adjusted as follow: subjects who weighed less than 55 kg were served 51 g egg white cooked with 12 g olive oil, which is equivalent to 40 g egg yolk; those who weighed from 55 kg to 65 kg were served 61 g egg white cooked with 14 g olive oil, which is equivalent to 48 g egg yolk; and those who weighed more than 65 kg were served 71 g egg white cooked with 17 g olive oil, which is equivalent to 56 g egg yolk.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in serum lipids | Serum lipids including serum total cholesterol, LDL-C, HDL-C and LDL-C/HDL-C, triglycerides | Week 0, week 4, week 8, week 16 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gene-by-Diet Interaction, Egg Yolk, Sterol Regulatory Element Binding Protein 1 Gene, HDL-C, LDL-C/HDL-C