Fatty Acid Desaturase Gene Locus Interactions With Diet (FADSDIET2) (FADSDIET2)

Interactions between genes and environment, are likely to be crucial in the development of the common diseases such as type 2 diabetes. Recently, the investigators have obtained data that genotypes of genes encoding for fatty acid desaturases 1 and 2 (FADS1 and FADS2) are the strongest genes in a genome-wide analysis regulating serum fatty acid profile.The aim of this study is to test if subjects with different genotypes of the FADS2 gene respond differently to a diet supplemented with linoleic acid or alpha-linolenic acid (substrates for FADS2). The study hypothesizes that subjects will be more sensitive to the dietary modifications according to their genotype leading to more robust differences in serum FA profile, tissue inflammation and serum lipids.

Study Overview

• Status: Completed
• Conditions: Genetics; Fatty Acids
• Intervention / Treatment: Dietary supplement: LA; Dietary supplement: ALA

Detailed Description

Lean and overweight subjects (Body mass index: BMI >20kg/m2 <32kg/m2 ) with CC and TT genotypes of FADS1 single nucleotide polymorphism (SNP) from the METabolic Syndrome in Men (METSIM) study, in which currently >10000 men are included from the population living in Kuopio, will be recruited. Seventy subjects with CC genotype will be selected after matching with the 70 subjects with the TT genotype for age and BMI.

After a 4-week run-in period, the subjects within each genotype group will be randomly assigned into two study groups according to medians of BMI, age and fasting plasma glucose concentration: in one group the diet will be enriched with linoleic acid (LA, sunflower oil) and in the other group with alpha-linolenic acid (ALA, camelina oil). The intervention will last for 8 weeks.

The sample size calculation is based on the observed change in arachidonic acid (AA) in the cholesterol esthers fraction between CC and TT genotypes (12.14 vs. 4.20 mol%, respectively) after the diet enriched in LA from preliminary data. Considering a β=0.80 and an α=0.025 instead of only 0.05 to account for the fact that we now have two dietary interventions instead of one, 31 participants in each study group would need to be included. Assuming around 15% of dropouts in this trial, a final sample size of 35 for each group is required.

The study diet will be isocaloric following the habitual diet of the participants with a supplement of 30-50 ml (25-45 g) sunflower or camelina oil daily depending on body weight. The dose of each oil is not known to cause any side effects or adverse events and even higher doses have been safe.

Participants will record their daily oil consumption and 4-day food records will be collected at the beginning and two times during the intervention period to measure daily intake of macronutrients and specifically different fatty acids.

• Study Type: Interventional
• Enrollment (Actual): 140
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Finland
  • Kuopio, Finland, 70211
    • University of Eastern Finland

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Participants of METSIM study cohort with CC/TT FADS1 rs174547 SNP genotype.
• BMI 20-32 kg/m2.
• Healthy .

Exclusion Criteria:

• Diagnosis of type 2 diabetes.
• Diagnosis of chronic diseases and conditions, that may hamper the ability to follow the dietary intervention protocol
• Chronic liver, thyroid and kidney diseases
• Alcohol abuse (> 40 g/d)
• BMI >32 kg/m2.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CC genotype LA; 4-week study diet will be isocaloric following the habitual diet of the participants with a supplement of 30-50 ml (5-6 % of energy intake) of sunflower oil (source of LA: linoleic acid) daily, depending on body weight. The same diet will be instructed for both genotypes.	Dietary supplement: LA; The source of linoleic acid (LA) will be sunflower oil (62-63 % LA). The study diets will be isocaloric. The allowed weight change during the study is ± 2-3 %. The amount of supplementary oil will be calculated individually based on the calculated energy expenditure and adjusted, if necessary, during the study based on body weight measurements.; Other Names: sunflower oil
Experimental: TT genotype LA; 4-week study diet will be isocaloric following the habitual diet of the participants with a supplement of 30-50 ml (5-6 % of energy intake) of sunflower oil (source of LA: linoleic acid) daily, depending on body weight. The same diet will be instructed for both genotypes.	Dietary supplement: LA; The source of linoleic acid (LA) will be sunflower oil (62-63 % LA). The study diets will be isocaloric. The allowed weight change during the study is ± 2-3 %. The amount of supplementary oil will be calculated individually based on the calculated energy expenditure and adjusted, if necessary, during the study based on body weight measurements.; Other Names: sunflower oil
Experimental: CC genotype ALA; 4-week study diet will be isocaloric following the habitual diet of the participants with a supplement of 30-50 ml (5-6 % of energy intake) of camelina oil (source of alpha-linolenic acid: ALA) daily, depending on body weight. The same diet will be instructed for both genotypes.	Dietary supplement: ALA; The source of alpha-linolenic acid (ALA) will be camelina sativa oil (30-35 % ALA). The study diets will be isocaloric. The allowed weight change during the study is ± 2-3 %. The amount of supplementary oil will be calculated individually based on the calculated energy expenditure and adjusted, if necessary, during the study based on body weight measurements.; Other Names: camelina oil
Experimental: TT genotype ALA; 4-week study diet will be isocaloric following the habitual diet of the participants with a supplement of 30-50 ml (5-6 % of energy intake) of camelina oil (source of alpha-linolenic acid: ALA) daily, depending on body weight. The same diet will be instructed for both genotypes.	Dietary supplement: ALA; The source of alpha-linolenic acid (ALA) will be camelina sativa oil (30-35 % ALA). The study diets will be isocaloric. The allowed weight change during the study is ± 2-3 %. The amount of supplementary oil will be calculated individually based on the calculated energy expenditure and adjusted, if necessary, during the study based on body weight measurements.; Other Names: camelina oil

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fatty acid composition of serum lipid fractions	Fatty acid composition of serum lipid fractions	8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glucose and insulin metabolism response	Oral glucose tolerance test (OGTT) variables: fasting, 30 min and 120 min glucose and insulin measurements	8 weeks
Inflammatory markers response	Serum circulating levels of high-sensitivity C-reactive protein	8 weeks
Adipose tissue biopsies	Subcutaneous adipose tissue taken by open biopsy to collect 1-5 g of adipose tissue.	8 weeks

Collaborators and Investigators

• Sponsor: University of Eastern Finland
• Investigators: Principal Investigator: Jussi Pihlajamäki, MD, University of Eastern Finland

Study record dates

Study Major Dates

• Study Start (Actual): August 13, 2018
• Primary Completion (Actual): December 19, 2018
• Study Completion (Actual): December 19, 2018

Study Registration Dates

• First Submitted: June 13, 2018
• First Submitted That Met QC Criteria: June 18, 2018
• First Posted (Actual): June 28, 2018

Study Record Updates

• Last Update Posted (Actual): April 18, 2019
• Last Update Submitted That Met QC Criteria: April 17, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Keywords: Nutrigenetics
• Other Study ID Numbers: FADSDIET2

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No