| 2. |
- Florez, Jose C, et al.
(författare)
-
Type 2 diabetes-associated missense polymorphisms KCNJ11 E23K and ABCC8 A1369S influence progression to diabetes and response to interventions in the Diabetes Prevention Program.
- 2007
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 56:2, s. 531-6
-
Tidskriftsartikel (refereegranskat)abstract
- The common polymorphisms KCNJ11 E23K and ABCC8 A1369S have been consistently associated with type 2 diabetes. We examined whether these variants are also associated with progression from impaired glucose tolerance (IGT) to diabetes and responses to preventive interventions in the Diabetes Prevention Program. We genotyped both variants in 3,534 participants and performed Cox regression analysis using genotype, intervention, and their interactions as predictors of diabetes incidence over ∼3 years. We also assessed the effect of genotype on insulin secretion and insulin sensitivity at 1 year. As previously shown in other studies, lysine carriers at KCNJ11 E23K had reduced insulin secretion at baseline; however, they were less likely to develop diabetes than E/E homozygotes. Lysine carriers were less protected by 1-year metformin treatment than E/E homozygotes (P < 0.02). Results for ABCC8 A1369S were essentially identical to those for KCNJ11 E23K. We conclude that the lysine variant in KCNJ11 E23K leads to diminished insulin secretion in individuals with IGT. Given our contrasting results compared with case-control analyses, we hypothesize that its effect on diabetes risk may occur before the IGT-to-diabetes transition. We further hypothesize that the diabetes-preventive effect of metformin may interact with the impact of these variants on insulin regulation.
|
|
| 3. |
- Florez, J, et al.
(författare)
-
Testing of diabetes-associated WFS1 polymorphisms in the Diabetes Prevention Program
- 2007
-
Ingår i: Diabetologia. - : Springer. - 0012-186X .- 1432-0428. ; 51:3, s. 451-457
-
Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: Wolfram syndrome (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) is caused by mutations in the WFS1 gene. Recently, single nucleotide polymorphisms (SNPs) in WFS1 have been reproducibly associated with type 2 diabetes. We therefore examined the effects of these variants on diabetes incidence and response to interventions in the Diabetes Prevention Program (DPP), in which a lifestyle intervention or metformin treatment was compared with placebo.Methods: We genotyped the WFS1 SNPs rs10010131, rs752854 and rs734312 (H611R) in 3,548 DPP participants and performed Cox regression analysis using genotype, intervention and their interactions as predictors of diabetes incidence. We also evaluated the effect of these SNPs on insulin resistance and beta cell function at 1 year.Results: Although none of the three SNPs was associated with diabetes incidence in the overall cohort, white homozygotes for the previously reported protective alleles appeared less likely to develop diabetes in the lifestyle arm. Examination of the publicly available Diabetes Genetics Initiative genome-wide association dataset revealed that rs10012946, which is in strong linkage disequilibrium with the three WFS1 SNPs (r 2 = 0.88–1.0), was associated with type 2 diabetes (allelic odds ratio 0.85, 95% CI 0.75–0.97, p = 0.026). In the DPP, we noted a trend towards increased insulin secretion in carriers of the protective variants, although for most SNPs this was seen as compensatory for the diminished insulin sensitivity.Conclusions/interpretation: The previously reported protective effect of select WFS1 alleles may be magnified by a lifestyle intervention. These variants appear to confer an improvement in beta cell function.
|
|
