The tumor necrosis factor-α gene -238G>A polymorphism, dietary fat intake, obesity risk and serum lipid concentrations in black and white South African women.
OBJECTIVE
This study explored interactions between dietary fat intake and the tumor necrosis factor-α gene (TNFA) -238G>A polymorphism (rs361525) on adiposity and serum lipid concentrations in apparently healthy premenopausal black and white South African (SA) women.


METHODS
Normal-weight (N=107) and obese (N=120) black, and normal-weight (N=89) and obese (N=62) white SA women underwent measurements of body composition, fasting lipids and dietary intake, and were genotyped for the -238G>A polymorphism.


RESULTS
Black women had a higher -238GA genotype frequency than white women (P<0.001), but there were no differences between body mass index groups. Black women with the -238A allele had a greater body fat % than those with the GG genotype (P<0.001). Further, in black women, with increasing polyunsaturated:saturated fat ratio and omega-6 (n-6):omega-3 (n-3) ratio, high-density lipoprotein-cholesterol (HDL-C) concentrations decreased, and total cholesterol (T-C):HDL-C ratio increased in those with the GA genotype but not the GG genotype. In addition, with increasing n-3 polyunsaturated fatty acid intake (percentage of total energy intake, %E), T-C:HDL-C ratio decreased in those with the GA genotype, but not in those with the GG genotype. In white SA women, with increasing eicosapentaenoic acid (%E) intake, low-density lipoprotein-cholesterol concentrations decreased in those with the GG genotype but not the GA genotype.


CONCLUSIONS
The -238G>A polymorphism was associated with body fatness in black women. Interactions between -238G>A genotypes and dietary fat intake on serum lipids and adiposity differed depending on dietary fat intake, but those for serum lipids were not the same in black and white SA women.
Department of Human Biology, UCT/MRC Research Unit for Exercise Science and Sports Medicine, University of Cape Town, Cape Town, South Africa.
Y T
YT
Joffe
L
L
van der Merwe
J
J
Evans
M
M
Collins
E V
EV
Lambert
A
A
September
J H
JH
Goedecke
D000273:Adipose Tissue / Q000187:drug effects*; D050154:Adiposity / Q000187:drug effects / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000483:Alleles; D044383:Black People / Q000235:genetics; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood* / Q000235:genetics; D004032:Diet; D004041:Dietary Fats / Q000097:blood / Q000494:pharmacology*; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000494:pharmacology; D005260:Female; D005838:Genotype; D006801:Humans; D009765:Obesity / Q000097:blood / Q000235:genetics*; D011110:Polymorphism, Genetic; D044469:Racial Groups / Q000235:genetics*; D012016:Reference Values; D012307:Risk Factors; D013019:South Africa; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D044465:White People / Q000235:genetics
D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D014409:Tumor Necrosis Factor-alpha; D002784:Cholesterol