Substitution of dietary ω-6 polyunsaturated fatty acids for saturated fatty acids decreases LDL apolipoprotein B-100 production rate in men with dyslipidemia associated with insulin resistance: a randomized controlled trial.

Abstract

Background:

The substitution of omega (ω)-6 (n-6) polyunsaturated fatty acids (PUFAs) for saturated fatty acids (SFAs) is advocated in cardiovascular disease prevention. The impact of this substitution on lipoprotein metabolism in subjects with dyslipidemia associated with insulin resistance (IR) remains unknown.

Objective:

In men with dyslipidemia and IR, we evaluated the impact of substituting ω-6 PUFAs for SFAs on the in vivo kinetics of apolipoprotein (apo) B-containing lipoproteins and on the intestinal expression of key genes involved in lipoprotein metabolism.

Design:

Dyslipidemic and IR men (n = 36) were recruited for this double-blind, randomized, crossover, controlled trial. Subjects consumed, in a random order, a fully controlled diet rich in SFAs (SFAs: 13.4% of energy; ω-6 PUFAs: 4.0%) and a fully controlled diet rich in ω-6 PUFAs (SFAs: 6.0%; ω-6 PUFAs: 11.3%) for periods of 4 wk, separated by a 4-wk washout period. At the end of each diet, the in vivo kinetics of apoB-containing lipoproteins were measured and the intestinal expression of key genes involved in lipoprotein metabolism was quantified in duodenal biopsies taken from each participant.

Results:

The substitution of ω-6 PUFAs for SFAs had no impact on TRL apoB-48 fractional catabolic rate (Δ = -3.8%, P = 0.7) and production rate (Δ = +1.2%, P = 0.9), although it downregulated the intestinal expression of the microsomal triglyceride transfer protein (Δ = -18.4%, P = 0.006) and apoB (Δ = -16.6%, P = 0.005). The substitution of ω-6 PUFAs for SFAs decreased the LDL apoB-100 pool size (Δ = -7.8%; P = 0.005). This difference was attributed to a reduction in the LDL apoB-100 production rate after the substitution of ω-6 PUFAs for SFAs (Δ = -10.0%; P = 0.003).

Conclusions:

This study demonstrates that the substitution of dietary ω-6 PUFAs for SFAs decreases the production and number of LDL particles in men with dyslipidemia and IR. This trial was registered at clinicaltrials.gov as NCT01934543.

• Authors: Jean-Philippe Drouin-Chartier, André J Tremblay, Marie-Claude Lépine, Valéry Lemelin, Benoît Lamarche, Patrick Couture
• Journal: The American journal of clinical nutrition (Am J Clin Nutr) Vol. 107 Issue 1 Pg. 26-34 (01 01 2018) ISSN: 1938-3207 [Electronic] United States
• PMID: 29381796 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 American Society for Nutrition. All rights reserved.

Chemical References

• Apolipoprotein B-100
• Apolipoprotein B-48
• Blood Glucose
• Dietary Carbohydrates
• Dietary Fats
• Dietary Proteins
• Fatty Acids
• Fatty Acids, Omega-6
• Insulin
• Triglycerides
• Cholesterol
• Aspartate Aminotransferases
• Alanine Transaminase

Topics

• Adolescent
• Adult
• Aged
• Alanine Transaminase (blood)
• Apolipoprotein B-100 (blood)
• Apolipoprotein B-48 (blood)
• Aspartate Aminotransferases (blood)
• Blood Glucose (metabolism)
• Cardiovascular Diseases (prevention & control)
• Cholesterol (blood)
• Cross-Over Studies
• Diet
• Dietary Carbohydrates (administration & dosage)
• Dietary Fats (administration & dosage)
• Dietary Proteins (administration & dosage)
• Double-Blind Method
• Dyslipidemias (blood, drug therapy)
• Fatty Acids (administration & dosage)
• Fatty Acids, Omega-6 (administration & dosage)
• Humans
• Insulin (blood)
• Insulin Resistance
• Male
• Middle Aged
• Sample Size
• Triglycerides (blood)
• Young Adult