Promoter Polymorphisms of the TNF-α (G-308A) and IL-6 (C-174G) Genes Predict the Conversion From Impaired Glucose Tolerance to Type 2 Diabetes
The Finnish Diabetes Prevention Study
- Agata Kubaszek1,
- Jussi Pihlajamäki1,
- Vladislav Komarovski1,
- Virpi Lindi2,
- Jaana Lindström3,
- Johan Eriksson3,
- Timo T. Valle3,
- Helena Hämäläinen4,
- Pirjo Ilanne-Parikka5,
- Sirkka Keinänen-Kiukaanniemi6,
- Jaakko Tuomilehto37,
- Matti Uusitupa2 and
- Markku Laakso1
- 1Department of Medicine, University of Kuopio, Kuopio, Finland
- 2Department of Clinical Nutrition, University of Kuopio, Kuopio, Finland
- 3Department of Epidemiology and Health Promotion, Diabetes and Genetic Epidemiology Unit, National Public Health Institute, Helsinki, Finland
- 4Research and Development Centre, Social Insurance Institution, Turku, Finland
- 5Department of Medicine, Finnish Diabetes Association and University of Tampere, Tampere, Finland
- 6Department of Public Health Science and General Practice, University of Oulu, Oulu University Hospital and Department of Sport Medicine, Oulu Deaconess Institute, Oulu, Finland
- 7Department of Public Health, University of Helsinki, Helsinki, Finland
- Address correspondence and reprint requests to Markku Laakso, Professor and Chair, Department of Medicine, University of Kuopio, 70210 Kuopio, Finland. E-mail: markku.laakso{at}kuh.fi
Abstract
High levels of cytokines are risk factors for type 2 diabetes. Therefore, we investigated whether the promoter polymorphisms of the tumor necrosis factor-α (TNF-α; G-308A) and interleukin 6 (IL-6; C-174G) genes predict the conversion from impaired glucose tolerance (IGT) to type 2 diabetes in the Finnish Diabetes Prevention Study. Altogether, 490 overweight subjects with IGT whose DNA was available were randomly divided into one of the two treatment assignments: the control group and the intensive, individualized diet and exercise intervention group. The −308A allele of the TNF-α gene was associated with an approximate twofold higher risk for type 2 diabetes compared with the G-308G genotype (odds ratio 1.80, 95% CI 1.05–3.09; P = 0.034). Subjects with both the A allele of the TNF-α gene and the C-174C genotype of the IL-6 gene had a 2.2-fold (CI 1.02–4.85, P = 0.045) higher risk of developing type 2 diabetes than subjects without the risk genotypes. We conclude that the −308A allele of the promoter polymorphism (G-308A) of the TNF-α gene is a predictor for the conversion from IGT to type 2 diabetes. Furthermore, this polymorphism seems to have a gene-gene interaction with the C-174C genotype of the IL-6 gene.
- DPS, Diabetes Prevention Study
- HOMA, homeostasis model assessment
- HOMA-IR, HOMA for insulin resistance
- HOMA-IS, HOMA for insulin secretion
- IGT, impaired glucose tolerance
- IL-6, interleukin-6
- TNF-α, tumor necrosis factor-α
Footnotes
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- Accepted April 8, 2003.
- Received February 9, 2003.
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