| 1. |
- Florez, Jose C., et al.
(författare)
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Effects of Genetic Variants Previously Associated with Fasting Glucose and Insulin in the Diabetes Prevention Program
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- Common genetic variants have been recently associated with fasting glucose and insulin levels in white populations. Whether these associations replicate in pre-diabetes is not known. We extended these findings to the Diabetes Prevention Program, a clinical trial in which participants at high risk for diabetes were randomized to placebo, lifestyle modification or metformin for diabetes prevention. We genotyped previously reported polymorphisms (or their proxies) in/near G6PC2, MTNR1B, GCK, DGKB, GCKR, ADCY5, MADD, CRY2, ADRA2A, FADS1, PROX1, SLC2A2, GLIS3, C2CD4B, IGF1, and IRS1 in 3,548 Diabetes Prevention Program participants. We analyzed variants for association with baseline glycemic traits, incident diabetes and their interaction with response to metformin or lifestyle intervention. We replicated associations with fasting glucose at MTNR1B (P<0.001), G6PC2 (P=0.002) and GCKR (P=0.001). We noted impaired beta-cell function in carriers of glucose-raising alleles at MTNR1B (P<0.001), and an increase in the insulinogenic index for the glucose-raising allele at G6PC2 (P<0.001). The association of MTNR1B with fasting glucose and impaired beta-cell function persisted at 1 year despite adjustment for the baseline trait, indicating a sustained deleterious effect at this locus. We also replicated the association of MADD with fasting proinsulin levels (P<0.001). We detected no significant impact of these variants on diabetes incidence or interaction with preventive interventions. The association of several polymorphisms with quantitative glycemic traits is replicated in a cohort of high-risk persons. These variants do not have a detectable impact on diabetes incidence or response to metformin or lifestyle modification in the Diabetes Prevention Program.
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| 2. |
- Billings, Liana K., et al.
(författare)
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The Influence of Rare Genetic Variation in SLC30A8 on Diabetes Incidence and beta-Cell Function
- 2014
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 99:5, s. 926-930
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Tidskriftsartikel (refereegranskat)abstract
- Context/Objective: The variant rs13266634 in SLC30A8, encoding a beta-cell-specific zinc transporter, is associated with type 2 diabetes. We aimed to identify other variants in SLC30A8 that increase diabetes risk and impair beta-cell function, and test whether zinc intake modifies this risk. Design/Outcome: We sequenced exons in SLC30A8 in 380 Diabetes Prevention Program (DPP) participants and identified 44 novel variants, which were genotyped in 3445 DPP participants and tested for association with diabetes incidence and measures of insulin secretion and processing. We examined individual common variants and used gene burden tests to test 39 rare variants in aggregate. Results: We detected a near-nominal association between a rare-variant genotype risk score and diabetes risk. Five common variants were associated with the oral disposition index. Various methods aggregating rare variants demonstrated associations with changes in oral disposition index and insulinogenic index during year 1 of follow-up. We did not find a clear interaction of zinc intake with genotype on diabetes incidence. Conclusions: Individual common and an aggregate of rare genetic variation in SLC30A8 are associated with measures of beta-cell function in the DPP. Exploring rare variation may complement ongoing efforts to uncover the genetic influences that underlie complex diseases.
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| 3. |
- Delahanty, Linda M., et al.
(författare)
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Genetic Predictors of Weight Loss and Weight Regain After Intensive Lifestyle Modification, Metformin Treatment, or Standard Care in the Diabetes Prevention Program
- 2012
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 35:2, s. 363-366
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-We tested genetic associations with weight loss and weight regain in the Diabetes Prevention Program, a randomized controlled trial of weight-loss inducing interventions (lifestyle and metformin) versus placebo. RESEARCH DESIGN AND METHODS-Sixteen obesity-predisposing single nucleotide polymorphisms (SNPs) were tested for association with short-term (baseline to 6 months) and long-term (baseline to 2 years) weight loss and weight regain (6 months to study end). RESULTS-Irrespective of treatment, the Ala12 allele at PPARG associated with short- and long-term weight loss (-0.63 and -0.93 kg/allele, P <= 0.005, respectively). Gene-treatment interactions were observed for short-term (LYPLAL1 rs2605100, P-lifestyle*SNP = 0.032; GNPDA2 rs10938397, P-lifestyle*SNP = 0.016; MTCH2 rs10838738, P-lifestyle*SNP = 0.022) and long-term (NEGR1 rs2815752, P-metformin*SNP = 0.028; FTO rs9939609, P-lifestyle*SNP = 0.044) weight loss. Three of 16 SNPs were associated with weight regain (NEGR1 rs2815752, BDNF rs6265, PPARG rs1801282), irrespective of treatment. TMEM18 rs6548238 and KTCD15 rs29941 showed treatment-specific effects (P-lifestyle*SNP < 0.05). CONCLUSIONS-Genetic information may help identify people who require additional support to maintain reduced weight after clinical intervention.
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| 4. |
- Franks, Paul, et al.
(författare)
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Common variation at PPARGC1A/B and change in body composition and metabolic traits following preventive interventions : the Diabetes Prevention Program
- 2014
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Ingår i: Diabetologia. - : Springer. - 0012-186X .- 1432-0428. ; 57:3, s. 485-490
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Tidskriftsartikel (refereegranskat)abstract
- PPARGC1A and PPARGCB encode transcriptional coactivators that regulate numerous metabolic processes. We tested associations and treatment (i.e. metformin or lifestyle modification) interactions with metabolic traits in the Diabetes Prevention Program, a randomised controlled trial in persons at high risk of type 2 diabetes. We used Tagger software to select 75 PPARGCA1 and 94 PPARGC1B tag single-nucleotide polymorphisms (SNPs) for analysis. These SNPs were tested for associations with relevant cardiometabolic quantitative traits using generalised linear models. Aggregate genetic effects were tested using the sequence kernel association test. In aggregate, PPARGC1A variation was strongly associated with baseline triacylglycerol concentrations (p = 2.9 x 10(-30)), BMI (p = 2.0 x 10(-5)) and visceral adiposity (p = 1.9 x 10(-4)), as well as with changes in triacylglycerol concentrations (p = 1.7 x 10(-5)) and BMI (p = 9.9 x 10(-5)) from baseline to 1 year. PPARGC1B variation was only associated with baseline subcutaneous adiposity (p = 0.01). In individual SNP analyses, Gly482Ser (rs8192678, PPARGC1A) was associated with accumulation of subcutaneous adiposity and worsening insulin resistance at 1 year (both p < 0.05), while rs2970852 (PPARGC1A) modified the effects of metformin on triacylglycerol levels (p (interaction) = 0.04). These findings provide several novel and other confirmatory insights into the role of PPARGC1A variation with respect to diabetes-related metabolic traits. Trial registration ClinicalTrials.gov NCT00004992.
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| 5. |
- Franks, Paul W, et al.
(författare)
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Childhood obesity, other cardiovascular risk factors, and premature death.
- 2010
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 362:6, s. 485-493
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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.
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| 6. |
- Hivert, Marie-France, et al.
(författare)
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Updated Genetic Score Based on 34 Confirmed Type 2 Diabetes Loci Is Associated With Diabetes Incidence and Regression to Normoglycemia in the Diabetes Prevention Program
- 2011
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 60:4, s. 1340-1348
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Over 30 loci have been associated with risk of type 2 diabetes at genome-wide statistical significance. Genetic risk scores (GRSs) developed from these loci predict diabetes in the general population. We tested if a GRS based on an updated list of 34 type 2 diabetes-associated loci predicted progression to diabetes or regression toward normal glucose regulation (NGR) in the Diabetes Prevention Program (DPP). RESEARCH DESIGN AND METHODS We genotyped 34 type 2 diabetes-associated variants in 2,843 DPP participants at high risk of type 2 diabetes from five ethnic groups representative of the U.S. population, who had been randomized to placebo, metformin, or lifestyle intervention. We built a GRS by weighting each risk allele by its reported effect size on type 2 diabetes risk and summing these values. We tested its ability to predict diabetes incidence or regression to NGR in models adjusted for age, sex, ethnicity, waist circumference, and treatment assignment. RESULTS lit multivariate-adjusted models, the GRS was significantly associated with increased risk of progression to diabetes (hazard ratio [HR] = 1.02 per risk allele [95% CI 1.00-1.05]; P = 0.03) and a lower probability of regression to NGR (HR = 0.95 per risk allele [95% CI 0.93-0.981; P < 0.0001). At baseline, a higher GRS was associated with a lower insulinogenic index (P < 0.001), confirming an impairment in beta-cell function. We detected no significant interaction between GRS and treatment, but the lifestyle intervention was effective in the highest quartile of ORS (P < 0.0001). CONCLUSIONS A high GRS is associated with increased risk of developing diabetes and lower probability of returning to NGR in high-risk individuals, but a lifestyle intervention attenuates this risk. Diabetes 60:1340-1348, 2011
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| 7. |
- McCaffery, Jeanne M., et al.
(författare)
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TCF7L2 Polymorphism, Weight Loss and Proinsulin: Insulin Ratio in the Diabetes Prevention Program
- 2011
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:7
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Tidskriftsartikel (refereegranskat)abstract
- Aims: TCF7L2 variants have been associated with type 2 diabetes, body mass index (BMI), and deficits in proinsulin processing and insulin secretion. Here we sought to test whether these effects were apparent in high-risk individuals and modify treatment responses. Methods: We examined the potential role of the TCF7L2 rs7903146 variant in predicting resistance to weight loss or a lack of improvement of proinsulin processing during 2.5-years of follow-up participants (N = 2,994) from the Diabetes Prevention Program (DPP), a randomized controlled trial designed to prevent or delay diabetes in high-risk adults. Results: We observed no difference in the degree of weight loss by rs7903146 genotypes. However, the T allele (conferring higher risk of diabetes) at rs7903146 was associated with higher fasting proinsulin at baseline (P, 0.001), higher baseline proinsulin: insulin ratio (p<0.0001) and increased proinsulin: insulin ratio over a median of 2.5 years of follow-up (P = 0.003). Effects were comparable across treatment arms. Conclusions: The combination of a lack of impact of the TCF7L2 genotypes on the ability to lose weight, but the presence of a consistent effect on the proinsulin: insulin ratio over the course of DPP, suggests that high-risk genotype carriers at this locus can successfully lose weight to counter diabetes risk despite persistent deficits in insulin production.
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| 8. |
- Pan, Qing, et al.
(författare)
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Variation at the Melanocortin 4 Receptor Gene and Response to Weight-Loss Interventions in the Diabetes Prevention Program
- 2013
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Ingår i: Obesity. - : Wiley-Blackwell. - 1930-7381 .- 1930-739X. ; 21:9, s. E520-E526
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess associations and genotype x treatment interactions for melanocortin 4 receptor (MC4R) locus variants and obesity-related traits.Design and Methods: Diabetes prevention program (DPP) participants (N = 3,819, of whom 3,356 were genotyped for baseline and 3,234 for longitudinal analyses) were randomized into intensive lifestyle modification (diet, exercise, weight loss), metformin or placebo control. Adiposity was assessed in a subgroup (n = 909) using computed tomography. All analyses were adjusted for age, sex, ethnicity and treatment.Results: The rs1943218 minor allele was nominally associated with short-term (6 month; P = 0.032) and long-term (2 year; P = 0.038) weight change. Eight SNPs modified response to treatment on short-term (rs17066856, rs9966412, rs17066859, rs8091237, rs17066866, rs7240064) or long-term (rs12970134, rs17066866) reduction in body weight, or diabetes incidence (rs17066829) (all P-interaction < 0.05).Conclusion: This is the first study to comprehensively assess the role of MC4R variants and weight regulation in a weight loss intervention trial. One MC4R variant was directly associated with obesity-related traits or diabetes; numerous other variants appear to influence body weight and diabetes risk by modifying the protective effects of the DPP interventions.
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| 9. |
- Sullivan, Shannon D., et al.
(författare)
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Genetic Risk of Progression to Type 2 Diabetes and Response to Intensive Lifestyle or Metformin in Prediabetic Women With and Without a History of Gestational Diabetes Mellitus
- 2014
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 37:4, s. 909-911
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE The Diabetes Prevention Program (DPP) trial investigated rates of progression to diabetes among adults with prediabetes randomized to treatment with placebo, metformin, or intensive lifestyle intervention. Among women in the DPP, diabetes risk reduction with metformin was greater in women with prior gestational diabetes mellitus (GDM) compared with women without GDM but with one or more previous live births. RESEARCH DESIGN AND METHODS We asked if genetic variability could account for these differences by comparing beta-cell function and genetic risk scores (GRS), calculated from 34 diabetes-associated loci, between women with and without histories of GDM. RESULTS beta-Cell function was reduced in women with GDM. The GRS was positively associated with a history of GDM; however, the GRS did not predict progression to diabetes or modulate response to intervention. CONCLUSIONS These data suggest that a diabetes-associated GRS is associated with development of GDM and may characterize women at risk for development of diabetes due to beta-cell dysfunction.
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| 10. |
- Bray, George A., et al.
(författare)
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Long-Term Safety, Tolerability, and Weight Loss Associated With Metformin in the Diabetes Prevention Program Outcomes Study
- 2012
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 35:4, s. 731-737
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-Metformin produced weight loss and delayed or prevented diabetes in the Diabetes Prevention Program (DPP). We examined its long-term safety and tolerability along with weight loss, and change in waist circumference during the DPP and its long-term follow-up. RESEARCH DESIGN AND METHODS-The randomized double-blind clinical trial of metformin or placebo followed by a 7-8-year open-label extension and analysis of adverse events, tolerability, and the effect of adherence on change in weight and waist circumference. RESULTS-No significant safety issues were identified. Gastrointestinal symptoms were more common in metformin than placebo participants and declined over time. During the DPP, average hemoglobin and hematocrit levels were slightly lower in the metformin group than in the placebo group. Decreases in hemoglobin and hematocrit in the metformin group occurred during the first year following randomization, with no further changes observed over time. During the DPP, metformin participants had reduced body weight and waist circumference compared with placebo (weight by 2.06 +/- 5.65% vs. 0.02 +/- 5.52%, P < 0.001, and waist circumference by 2.13 +/- 7.06 cm vs. 0.79 +/- 6.54 cm, P < 0.001 in metformin vs. placebo, respectively). The magnitude of weight loss during the 2-year double-blind period was directly related to adherence (P < 0.001). Throughout the unblinded follow-up, weight loss remained significantly greater in the metformin group than in the placebo group (2.0 vs. 0.2%, P < 0.001), and this was related to the degree of continuing metformin adherence (P < 0.001). CONCLUSIONS-Metformin used for diabetes prevention is safe and well tolerated. Weight loss is related to adherence to metformin and is durable for at least 10 years of treatment.
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