| 1. |
- 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.
|
|
| 2. |
|
|
| 3. |
- Billings, Liana K., et al.
(författare)
-
Increased Genetic Risk for b-Cell Failure Is Associated With b-Cell Function Decline in People With Prediabetes
- 2024
-
Ingår i: Diabetes. - 0012-1797. ; 73:8, s. 1352-1360
-
Tidskriftsartikel (refereegranskat)abstract
- Partitioned polygenic scores (pPS) have been developed to capture pathophysiologic processes underlying type 2 diabetes (T2D). We investigated the association of T2D pPS with diabetes-related traits and T2D incidence in the Diabetes Prevention Program. We generated five T2D pPS (b-cell, proinsulin, liver/lipid, obesity, lipodystrophy) in 2,647 participants randomized to intensive lifestyle, metformin, or placebo arms. Associations were tested with general linear models and Cox regression with adjustment for age, sex, and principal components. Sensitivity analyses included adjustment for BMI. Higher b-cell pPS was associated with lower insulinogenic index and corrected insulin response at 1-year follow-up with adjustment for baseline measures (effect per pPS SD 20.04, P = 9.6 × 1027, and 28.45 lU/mg, P = 5.6 × 1026, respec-tively) and with increased diabetes incidence with adjustment for BMI at nominal significance (hazard ratio 1.10 per SD, P = 0.035). The liver/lipid pPS was associated with reduced 1-year baseline-adjusted triglyceride levels (effect per SD 24.37, P = 0.001). There was no significant interaction between T2D pPS and randomized groups. The remaining pPS were associated with baseline measures only. We conclude that despite interventions for diabetes prevention, participants with a high genetic burden of the b-cell cluster pPS had worsening in measures of b-cell function.
|
|
| 4. |
- Billings, Liana K., et al.
(författare)
-
Variation in maturity-onset diabetes of the young genes influence response to interventions for diabetes prevention
- 2017
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 102:8, s. 2678-2689
-
Tidskriftsartikel (refereegranskat)abstract
- Context: Variation in genes that cause maturity-onset diabetes of the young (MODY) has been associated with diabetes incidence and glycemic traits. Objectives: This study aimed to determine whether genetic variation in MODY genes leads to differential responses to insulin-sensitizing interventions. Design and Setting: This was a secondary analysis of a multicenter, randomized clinical trial, the Diabetes Prevention Program (DPP), involving 27 US academic institutions. We genotyped 22 missense and 221 common variants in the MODY-causing genes in the participants in the DPP. Participants and Interventions: The study included 2806 genotyped DPP participants randomized to receive intensive lifestyle intervention (n = 935), metformin (n = 927), or placebo (n = 944). Main Outcome Measures: Association of MODY genetic variants with diabetes incidence at a median of 3 years and measures of 1-year β-Cell function, insulinogenic index, and oral disposition index. Analyses were stratified by treatment group for significant single-nucleotide polymorphism 3 treatment interaction (Pint, 0.05). Sequence kernel association tests examined the association between an aggregate of rare missense variants and insulinogenic traits. Results: After 1 year, the minor allele of rs3212185 (HNF4A) was associated with improved β-Cell function in the metformin and lifestyle groups but not the placebo group; the minor allele of rs6719578 (NEUROD1) was associated with an increase in insulin secretion in the metformin group but not in the placebo and lifestyle groups. Conclusions: These results provide evidence that genetic variation among MODY genes may influence response to insulin-sensitizing interventions.
|
|
| 5. |
- Franks, Paul, et al.
(författare)
-
Common variation in PPARGC1A/B and progression to diabetes or change in metabolic traits following preventive interventions: the Diabetes Prevention Program.
- 2013
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X.
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: PPARGC1A and PPARGC1B encode transcriptional coactivators that regulate numerous type 2 diabetes-related metabolic processes. Common genetic variation across PPARGC1A/B was characterised by genotyping tagging variants. We then tested associations of these variants with diabetes incidence or change in quantifiable metabolic traits directly or via interactions (with metformin treatment or intensive lifestyle modification) in the Diabetes Prevention Program (DPP), a randomised controlled trial in persons at high risk of type 2 diabetes. METHODS: We used Tagger software to select 75 PPARGC1A and 94 PPARGC1B tag single nucleotide polymorphisms (SNPs) for analysis. These SNPs were tested for association with diabetes incidence using Cox proportional hazards regression models, and a range of relevant metabolic quantifiable traits, using generalised linear models. RESULTS: Eight PPARGC1A variants were nominally (p < 0.05) associated with diabetes incidence, of which one (rs3736265/Thr612Met) was associated with diabetes in the DPP (HR 1.31, 95% CI 1.05, 1.63 per copy of the 612Met allele) and in the DIAGRAM database (OR 1.11, 95% CI 1.01, 1.21). Consistent with earlier reports, the Gly482Ser (rs8192678) variant showed nominally significant effects on 1 year accumulation of adiposity and worsening insulin resistance (both p < 0.05). A third PPARGC1A variant (rs2970852) modified the effects of metformin on triacylglycerol levels (p interaction = 0.04; p = 0.0001 for association of SNP with triacylglycerol concentrations in metformin-treated participants). A number of other PPARGC1A/B variants were nominally directly associated with diabetes incidence or modified treatment effects on diabetes incidence. CONCLUSIONS/INTERPRETATION: These findings provide some novel and confirmatory insights into the roles of PPARGC1A/B variation in type 2 diabetes and related metabolic traits. TRIAL REGISTRATION: ClinicalTrials.gov NCT00004992.
|
|
| 6. |
|
|
| 7. |
- Franks, Paul W, et al.
(författare)
-
Assessing gene-treatment interactions at the FTO and INSIG2 loci on obesity-related traits in the Diabetes Prevention Program
- 2008
-
Ingår i: Diabetologia. - New York : Springer. - 0012-186X .- 1432-0428. ; 51:12, s. 2214-2223
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: The single nucleotide polymorphism (SNP) rs9939609 in the fat mass and obesity associated gene (FTO) and the rs7566605 SNP located 10 kb upstream of the insulin-induced gene 2 gene (INSIG2) have been proposed as risk factors for common obesity.METHODS: We tested for genotype-treatment interactions on changes in obesity-related traits in the Diabetes Prevention Program (DPP). The DPP is a randomised controlled trial of 3,548 high-risk individuals from 27 participating centres throughout the USA who were originally randomised to receive metformin, troglitazone, intensive lifestyle modification or placebo to prevent the development of type 2 diabetes. Measures of adiposity from computed tomography were available in a subsample (n = 908). This report focuses on the baseline and 1 year results.RESULTS: The minor A allele at FTO rs9939609 was positively associated with baseline BMI (p = 0.003), but not with baseline adiposity or the change at 1 year in any anthropometric trait. For the INSIG2 rs7566605 genotype, the minor C allele was associated with more subcutaneous adiposity (second and third lumbar vertebrae [L2/3]) at baseline (p = 0.04). During follow-up, CC homozygotes lost more weight than G allele carriers (p = 0.009). In an additive model, we observed nominally significant gene-lifestyle interactions on weight change (p = 0.02) and subcutaneous (L2/3 [p = 0.01] and L4/5 [p = 0.03]) and visceral (L2/3 [p = 0.02]) adipose areas. No statistical evidence of association with physical activity energy expenditure or energy intake was observed for either genotype.CONCLUSIONS/INTERPRETATION: Within the DPP study population, common variants in FTO and INSIG2 are nominally associated with quantitative measures of obesity, directly and possibly by interacting with metformin or lifestyle intervention.
|
|
| 8. |
- Franks, Paul W, et al.
(författare)
-
Childhood obesity, other cardiovascular risk factors, and premature death.
- 2010
-
Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 362:6, s. 485-493
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The effect of childhood risk factors for cardiovascular disease on adult mortality is poorly understood. METHODS: In a cohort of 4857 American Indian children without diabetes (mean age, 11.3 years; 12,659 examinations) who were born between 1945 and 1984, we assessed whether body-mass index (BMI), glucose tolerance, and blood pressure and cholesterol levels predicted premature death. Risk factors were standardized according to sex and age. Proportional-hazards models were used to assess whether each risk factor was associated with time to death occurring before 55 years of age. Models were adjusted for baseline age, sex, birth cohort, and Pima or Tohono O'odham Indian heritage. RESULTS: There were 166 deaths from endogenous causes (3.4% of the cohort) during a median follow-up period of 23.9 years. Rates of death from endogenous causes among children in the highest quartile of BMI were more than double those among children in the lowest BMI quartile (incidence-rate ratio, 2.30; 95% confidence interval [CI], 1.46 to 3.62). Rates of death from endogenous causes among children in the highest quartile of glucose intolerance were 73% higher than those among children in the lowest quartile (incidence-rate ratio, 1.73; 95% CI, 1.09 to 2.74). No significant associations were seen between rates of death from endogenous or external causes and childhood cholesterol levels or systolic or diastolic blood-pressure levels on a continuous scale, although childhood hypertension was significantly associated with premature death from endogenous causes (incidence-rate ratio, 1.57; 95% CI, 1.10 to 2.24). CONCLUSIONS: Obesity, glucose intolerance, and hypertension in childhood were strongly associated with increased rates of premature death from endogenous causes in this population. In contrast, childhood hypercholesterolemia was not a major predictor of premature death from endogenous causes.
|
|
| 9. |
- Jablonski, K A, et al.
(författare)
-
Common variants in 40 genes assessed for diabetes incidence and response to metformin and lifestyle intervention in the diabetes prevention program
- 2010
-
Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; Oct:59(10), s. 2672-2681
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Genome-wide association studies have begun to elucidate the genetic architecture of type 2 diabetes. We examined whether single nucleotide polymorphisms (SNPs) identified through targeted complementary approaches affect diabetes incidence in the at-risk population of the Diabetes Prevention Program (DPP) and whether they influence a response to preventive interventions. RESEARCH DESIGN AND METHODS: We selected SNPs identified by prior genome-wide association studies for type 2 diabetes and related traits, or capturing common variation in 40 candidate genes previously associated with type 2 diabetes, implicated in monogenic diabetes, encoding type 2 diabetes drug targets or drug-metabolizing/transporting enzymes, or involved in relevant physiological processes. We analyzed 1,590 SNPs for association with incident diabetes and their interaction with response to metformin or lifestyle interventions in 2,994 DPP participants. We controlled for multiple hypothesis testing by assessing false discovery rates. RESULTS: We replicated the association of variants in the metformin transporter gene SLC47A1 with metformin response and detected nominal interactions in the AMP kinase (AMPK) gene STK11, the AMPK subunit genes PRKAA1 and PRKAA2, and a missense SNP in SLC22A1, which encodes another metformin transporter. The most significant association with diabetes incidence occurred in the AMPK subunit gene PRKAG2 (hazard ratio 1.24, 95% CI 1.09-1.40, P = 7 × 10(-4)). Overall, there were nominal associations with diabetes incidence at 85 SNPs and nominal interactions with the metformin and lifestyle interventions at 91 and 69 mostly nonoverlapping SNPs, respectively. The lowest P values were consistent with experiment-wide 33% false discovery rates. CONCLUSIONS: We have identified potential genetic determinants of metformin response. These results merit confirmation in independent samples.
|
|
| 10. |
|
|
