AIMS/HYPOTHESIS: The incidence of Type 1 diabetes has increased 2.5 times during the time period from 1966 to 2000 in Finland-a general trend seen in almost all developed countries that can only be explained by environmental factors. The aim of this study was to test the possible effect of a changing environment on distribution of genotypes associated with disease susceptibility. METHODS: HLA DRB1-DQA1-DQB1 genes and two diabetes-associated polymorphisms at IDDM2 and IDDM12 were analyzed. The frequencies of genotypes were compared between cases diagnosed with childhood-onset Type 1 diabetes during the period of 1939-1965 (n=367) and those diagnosed between 1990 and 2001 (n=736). Chi-square statistics or the Fisher's Exact test were used for the comparison of frequencies of analyzed haplotypes and genotypes in the two groups. RESULTS: The frequencies of (DR3) -DQA1*05-DQB1*02 and (DR4) -DQB1*0302 risk haplotypes and the high risk (DR3) -DQA1*05-DQB1*02/DRB1*0401-DQB1*0302 genotype were higher while proportion of patients carrying protective haplotypes-(DR15) -DQB1*0602 and (DR1301) -DQB1*0603-or protective genotypes was lower in patients diagnosed before 1965 as compared to those who developed disease after 1990. No temporal variation was found in the frequencies of genotypes at IDDM2 and IDDM12. CONCLUSION/ INTERPRETATION: Our data suggest that the need for genetic susceptibility to develop Type 1 diabetes has decreased over time due to an increasing environmental pressure and this results in a higher disease progression rate especially in subjects with protective HLA genotypes.
AIMS/HYPOTHESIS: The incidence of Type 1 diabetes has increased 2.5 times during the time period from 1966 to 2000 in Finland-a general trend seen in almost all developed countries that can only be explained by environmental factors. The aim of this study was to test the possible effect of a changing environment on distribution of genotypes associated with disease susceptibility. METHODS: HLA DRB1-DQA1-DQB1 genes and two diabetes-associated polymorphisms at IDDM2 and IDDM12 were analyzed. The frequencies of genotypes were compared between cases diagnosed with childhood-onset Type 1 diabetes during the period of 1939-1965 (n=367) and those diagnosed between 1990 and 2001 (n=736). Chi-square statistics or the Fisher's Exact test were used for the comparison of frequencies of analyzed haplotypes and genotypes in the two groups. RESULTS: The frequencies of (DR3) -DQA1*05-DQB1*02 and (DR4) -DQB1*0302 risk haplotypes and the high risk (DR3) -DQA1*05-DQB1*02/DRB1*0401-DQB1*0302 genotype were higher while proportion of patients carrying protective haplotypes-(DR15) -DQB1*0602 and (DR1301) -DQB1*0603-or protective genotypes was lower in patients diagnosed before 1965 as compared to those who developed disease after 1990. No temporal variation was found in the frequencies of genotypes at IDDM2 and IDDM12. CONCLUSION/ INTERPRETATION: Our data suggest that the need for genetic susceptibility to develop Type 1 diabetes has decreased over time due to an increasing environmental pressure and this results in a higher disease progression rate especially in subjects with protective HLA genotypes.
Authors: E Zablackis; W S York; M Pauly; S Hantus; W D Reiter; C C Chapple; P Albersheim; A Darvill Journal: Science Date: 1996-06-21 Impact factor: 47.728
Authors: J Tuomilehto; M Rewers; A Reunanen; P Lounamaa; R Lounamaa; E Tuomilehto-Wolf; H K Akerblom Journal: Diabetologia Date: 1991-04 Impact factor: 10.122
Authors: Mikko Laaksonen; Tomi Pastinen; Minna Sjöroos; Satu Kuokkanen; Juhani Ruutiainen; Marja Liisa Sumelahti; Helena Reijonen; Reijo Salonen; Juhani Wikström; Martin Panelius; Jukka Partanen; Pentti J Tienari; Jorma Ilonen Journal: J Neuroimmunol Date: 2002-01 Impact factor: 3.478
Authors: S Caillat-Zucman; H J Garchon; J Timsit; R Assan; C Boitard; I Djilali-Saiah; P Bougnères; J F Bach Journal: J Clin Invest Date: 1992-12 Impact factor: 14.808
Authors: David M Maahs; Nancy A West; Jean M Lawrence; Elizabeth J Mayer-Davis Journal: Endocrinol Metab Clin North Am Date: 2010-09 Impact factor: 4.741
Authors: Rebecca B Lipton; Melinda L Drum; Kirstie K Danielson; Siri Aw Greeley; Graeme I Bell; William A Hagopian Journal: Pediatr Diabetes Date: 2011-03-23 Impact factor: 4.866
Authors: C Guja; L Guja; S Nutland; H Rance; M Sebastien; J A Todd; C Ionescu-Tirgoviste Journal: J Cell Mol Med Date: 2004 Apr-Jun Impact factor: 5.310