title: The TNF-beta gene Nco I polymorphism is not associated with hypertriglyceridemia or insulin resistance in lean and obese subjects.
abstract: Interindividual differences in TNF-alpha monocyte responses can be accounted for by genetic polymorphisms at the TNF-beta locus defined by the Nco I restriction enzyme. Higher triglyceride levels in non-insulin-dependent diabetic patients homozygous at the 10.5-kb fragment of the TNF-beta gene have been described. The aim of this study was to investigate whether the Ncol polymorphism of the TNF-beta gene influences the relationship between insulin resistance and triglyceride levels. Thirty-eight healthy volunteers were divided into two groups according to the absence [homozygous for class 1 allele (1/1), n=16] or presence of the class 2 allele [n=22; 19 heterozygous (1/2), and 3 homozygous (2/2)]. Both groups were comparable in sex, age, BMI, waist/hip ratio, fat mass and percentage of body fat as measured by bioelectric impedance, skinfold measurements, and blood pressure (all p>0.05). There were no differences in serum cholesterol (total, or HDL and VLDL fractions) or in total or VLDL triglycerides between the groups (all p>0.05). The insulin sensitivity index (Minimal Model method) was comparable for the two groups. In summary, the 10.5-kb homozygous genotype of the TNF-beta locus does not contribute to differences in triglyceride levels or insulin sensitivity among nondiabetic subjects.
authors.affiliation: Department of Endocrinology, Hospital de Girona, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Fernández-Real
authors.forename: C
authors.initials: C
authors.lastname: Gutierrez
authors.forename: W
authors.initials: W
authors.lastname: Ricart
authors.forename: R
authors.initials: R
authors.lastname: Casamitjana
authors.forename: M
authors.initials: M
authors.lastname: Broch
authors.forename: J
authors.initials: J
authors.lastname: Vendrell
authors.forename: C
authors.initials: C
authors.lastname: Richart
authors.forename: W
authors.initials: W
authors.lastname: Ricant
mesh_terms: D000328:Adult; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D015252:Deoxyribonucleases, Type II Site-Specific; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics; D017097:Electric Impedance; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D015228:Hypertriglyceridemia / Q000235:genetics*; D007333:Insulin Resistance / Q000235:genetics*; D008233:Lymphotoxin-alpha / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D008233:Lymphotoxin-alpha; C052380:endodeoxyribonuclease NcoI; D015252:Deoxyribonucleases, Type II Site-Specific