Impact of the Pro12Ala polymorphism of the PPAR-(gamma)2 gene on serum triacylglycerol response to n-3 fatty acid supplementation

Serum lipid responses to dietary modification are partly determined by genetic factors. The objective of the present study was to investigate the influence of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-(gamma)2 (PPAR-(gamma)2) gene on serum lipid and lipoprotein responses to n-3 fatty acid supplementation. A total of 76 men and 74 women (age 49+-8 years, body mass index 26.5+-3.0 kg/m^2) participated in a controlled multicenter study. Subjects were randomly assigned to consume either fish oil supplements (3.6 g n-3 fatty acids/day containing 2.4 g of EPA and DHA) or placebo capsules containing olive oil for 3 months. At baseline, the Pro12Ala polymorphism was not associated with serum total and lipoprotein lipid concentrations or lipoprotein lipase activity in the fasting state. After the 3-month study period, carriers of the Ala12 allele presented a greater decrease in serum triacylglycerol concentration in response to n-3 fatty acid supplementation than did subjects with the Pro12Pro genotype when the total dietary fat intake was below 37 E% (p=0.003) or the intake of saturated fatty acids was below 10 E% (p=0.006). Changes in serum total cholesterol, serum LDL cholesterol and HDL cholesterol concentrations were similar among the genotypes in the n-3 fatty acid supplementation group and in the placebo group. In conclusion, the Pro12Ala polymorphism of the PPAR-(gamma)2 gene may modify the interindividual variability in serum triacylglycerol response to n-3 fatty acid supplementation.