APOA5 gene gene variant may protect against obesity
MedWire News: A minor allele (C) of the apolipoprotein A-5 (APOA5) gene may offer protection against body fat accumulation and elevated plasma triglyceride levels in people who consume high-fat diets, study results indicate.
The researchers found significant genotype-dietary fat interactions for obesity traits and triglyceride-rich lipoprotein concentrations in individuals with the APOA5 -1131 T>C single nucleotide polymorphism (SNP).
Writing in The Journal of Nutrition the authors say that their results "highlight the potential usefulness of a nutrigenomic approach in optimizing a dietary intervention for the prevention of obesity and cardiovascular disease based on fat intake recommendations that are tailored to the individual genotype."
Jose Ordovás, from Tufts University in Boston, Massachusetts, USA, and colleagues recruited 1465 overweight or obese (body mass index [BMI] 25-40 kg/m2 ) Spanish individuals (aged 20-65 years), who attended outpatient obesity clinics between 2009 and 2010.
All participants self-reported their food consumption daily and underwent genotyping of the APOA5 -1131 T>C SNP.
In total, 0.3% of the population were homozygous for the minor allele (CC), 11.5% had one copy (CT), and 88.2% were homozygous for the major allele (TT).
In major allele homozygotes, high fat intake (greater than the mean of 98 g/day), compared with a low fat intake (less than or equal to the mean), was associated with significantly higher mean BMI (31.1 vs 30.4 kg/m2, respectively), and waist (102.0 cm vs 98.9 cm) and hip (114.3 vs 111.4 cm) measurements.
In contrast, individuals carrying the APOA5 SNP showed no associations between higher fat intake and measures of obesity.
The team also found that fat intake was inversely related to triglycerides and very low-density lipoprotein cholesterol concentrations in carriers of the C allele, but not in noncarriers.
Because most participants were noncarriers, the researchers say that their data indicate that saturated fat intake tends to cause obesity in the majority of the population.
Ordovás and team suggest, however, that individuals carrying the minor allele may be more resistant to the obesogenic effects of high fat intake.
"Evidence of APOA5 genotype modulation of the effect of dietary fat on two important cardiovascular disease risk factors (triglycerides and BMI) strengthens the hypothesis that gene-diet interactions underlie associations between APOA5 and cardiovascular disease," they conclude.
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By Nikki Withers