Polymorphisms in Fatty Acid Desaturase (FADS) Gene Cluster: Effects on Glycemic Controls Following an Omega-3 Polyunsaturated Fatty Acids (PUFA) Supplementation.
Changes in desaturase activity are associated with insulin sensitivity and may be associated with type 2 diabetes mellitus (T2DM). Polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene cluster have been associated with the homeostasis model assessment of insulin sensitivity (HOMA-IS) and serum fatty acid composition.


OBJECTIVE
To investigate whether common genetic variations in the FADS gene cluster influence fasting glucose (FG) and fasting insulin (FI) responses following a 6-week n-3 polyunsaturated fatty acids (PUFA) supplementation.


METHODS
210 subjects completed a 2-week run-in period followed by a 6-week supplementation with 5 g/d of fish oil (providing 1.9 g-2.2 g of EPA + 1.1 g of DHA). Genotyping of 18 SNPs of the FADS gene cluster covering 90% of all common genetic variations (minor allele frequency ≥ 0.03) was performed.


RESULTS
Carriers of the minor allele for rs482548 (FADS2) had increased plasma FG levels after the n-3 PUFA supplementation in a model adjusted for FG levels at baseline, age, sex, and BMI. A significant genotype*supplementation interaction effect on FG levels was observed for rs482548 (p = 0.008). For FI levels, a genotype effect was observed with one SNP (rs174456). For HOMA-IS, several genotype*supplementation interaction effects were observed for rs7394871, rs174602, rs174570, rs7482316 and rs482548 (p = 0.03, p = 0.01, p = 0.03, p = 0.05 and p = 0.07; respectively).


CONCLUSIONS
RESULTS suggest that SNPs in the FADS gene cluster may modulate plasma FG, FI and HOMA-IS levels in response to n-3 PUFA supplementation.
Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, QC, G1V 0A6, Canada. hubert.cormier.1@ulaval.ca.
Hubert
H
Cormier
Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, QC, G1V 0A6, Canada. iwona.rudkowska@fsaa.ulaval.ca.
Iwona
I
Rudkowska
Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, QC, G1V 0A6, Canada. elisabeth.thifault@fsaa.ulaval.ca.
Elisabeth
E
Thifault
Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, QC, G1V 0A6, Canada. simone.lemieux@fsaa.ulaval.ca.
Simone
S
Lemieux
Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, QC, G1V 0A6, Canada. patrick.couture@crchul.ulaval.ca.
Patrick
P
Couture
Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, QC, G1V 0A6, Canada. marie-claude.vohl@fsaa.ulaval.ca.
Marie-Claude
MC
Vohl