title: TNF-alpha polymorphisms and type 2 diabetes mellitus in Taiwanese patients.
abstract: Type 2 diabetic mellitus (type 2 DM) comprises more than 95% of all Taiwanese patients with DM. Tumor necrosis factor-alpha (TNF-alpha) expression is linked with insulin resistance, and is under strong genetic control. The correlation between TNF promoter genotypes and type 2 DM is still controversial, because discrepancies among different studies exist. Ethnic differences play certain roles in these conflicting results, because the distribution of TNF promoter polymorphisms is different among study subjects with different racial origins. Therefore, we examined the relationship between the incidence of type 2 diabetes in Taiwanese and two polymorphisms of the TNF-alpha promoter region (positions -238 and -308) as well as the correlation between these polymorphisms and the patients' biochemical manifestations. Genomic DNA was extracted from peripheral blood cells of 261 Taiwanese patients with type 2 DM and 189 non-diabetic control study subjects, and their TNF promoter G-238A and G-308A polymorphisms were analyzed by PCR-RFLP analysis. No significant association between TNF-alpha G-238A and G-308A polymorphisms with type 2 diabetic incidence was observed. However, associations between TNF-alpha G-238A and low-density lipoprotein-cholesterol and between G-308A promoter polymorphism and high-fasting plasma glucose levels, using multiple linear regression analysis with adjustment for the subjects' age, sex, body mass index and diabetic status, were found. Our results suggested that though TNF-alpha G-238A and G-308A polymorphisms were not involved in the pathogenesis of type 2 DM, type 2 diabetic patients carrying TNFA-A or TNF-308*2 genotype might be more susceptible to diabetic complications such as atherosclerosis.
authors.affiliation: Hung Kuang University, Institute of Medicine, and Institute of Immunology, Chung Shan Medical University, Taichung, Taiwan, Republic of China.
authors.forename: M-Y
authors.initials: MY
authors.lastname: Shiau
authors.forename: C-Y
authors.initials: CY
authors.lastname: Wu
authors.forename: C-N
authors.initials: CN
authors.lastname: Huang
authors.forename: S-W
authors.initials: SW
authors.lastname: Hu
authors.forename: S-J
authors.initials: SJ
authors.lastname: Lin
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chang
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016022:Case-Control Studies; D008078:Cholesterol, LDL / Q000378:metabolism; D004247:DNA / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D005838:Genotype; D018149:Glucose Intolerance / Q000235:genetics*; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic; D013624:Taiwan / Q000453:epidemiology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D001786:Blood Glucose; D008078:Cholesterol, LDL; D014409:Tumor Necrosis Factor-alpha; D004247:DNA