| 1. |
- Abrahamsson, Niclas, 1976-, et al.
(författare)
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Gastric bypass reduces symptoms and hormonal responses to hypoglycemia
- 2016
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 65:9, s. 2667-2675
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Tidskriftsartikel (refereegranskat)abstract
- Gastric bypass (GBP) surgery, one of the most common bariatric procedures, induces weight loss and metabolic effects. The mechanisms are not fully understood, but reduced food intake and effects on gastrointestinal hormones are thought to contribute. We recently observed that GBP patients have lowered glucose levels and frequent asymptomatic hypoglycemic episodes. Here, we subjected patients before and after undergoing GBP surgery to hypoglycemia and examined symptoms and hormonal and autonomic nerve responses. Twelve obese patients without diabetes (8 women, mean age 43.1 years [SD 10.8] and BMI 40.6 kg/m(2) [SD 3.1]) were examined before and 23 weeks (range 19-25) after GBP surgery with hyperinsulinemic-hypoglycemic clamp (stepwise to plasma glucose 2.7 mmol/L). The mean change in Edinburgh Hypoglycemia Score during clamp was attenuated from 10.7 (6.4) before surgery to 5.2 (4.9) after surgery. There were also marked postsurgery reductions in levels of glucagon, cortisol, and catecholamine and the sympathetic nerve responses to hypoglycemia. In addition, growth hormone displayed a delayed response but to a higher peak level. Levels of glucagon-like peptide 1 and gastric inhibitory polypeptide rose during hypoglycemia but rose less postsurgery compared with presurgery. Thus, GBP surgery causes a resetting of glucose homeostasis, which reduces symptoms and neurohormonal responses to hypoglycemia. Further studies should address the underlying mechanisms as well as their impact on the overall metabolic effects of GBP surgery.
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| 2. |
- Fitipaldi, Hugo, et al.
(författare)
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A Global Overview of Precision Medicine in Type 2 Diabetes
- 2018
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 67:10, s. 1911-1922
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Tidskriftsartikel (refereegranskat)abstract
- The detailed characterization of human biology and behaviors is now possible at scale owing to innovations in biomarkers, bioimaging, and wearable technologies; "big data" from electronic medical records, health insurance databases, and other platforms becoming increasingly accessible; and rapidly evolving computational power and bioinformatics methods. Collectively, these advances are creating unprecedented opportunities to better understand diabetes and many other complex traits. Identifying hidden structures within these complex data sets and linking these structures to outcome data may yield unique insights into the risk factors and natural history of diabetes, which in turn may help optimize the prevention and management of the disease. This emerging area is broadly termed "precision medicine." In this Perspective, we give an overview of the evidence and barriers to the development and implementation of precision medicine in type 2 diabetes. We also discuss recently presented paradigms through which complex data might enhance our understanding of diabetes and ultimately our ability to tackle the disease more effectively than ever before.
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| 3. |
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| 4. |
- Hivert, Marie-France, et al.
(författare)
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Lifestyle and metformin ameliorate insulin sensitivity independently of the genetic burden of established insulin resistance variants in Diabetes Prevention Program participants.
- 2016
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 65:2, s. 520-526
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies of glycemic traits have identified genetics variants that are associated with insulin resistance (IR) in the general population. It is unknown if people with genetic enrichment for these IR-variants respond differently to interventions that aim to improve insulin sensitivity. We built a genetic risk score based on 17 established IR-variants and their effect sizes (weighted IR-GRS) in 2,713 participants of the Diabetes Prevention Program (DPP) with genetic consent. We tested associations between the weighted IR-GRS and insulin sensitivity index (ISI) at baseline in all participants, and with change in ISI over 1-year of follow-up in DPP intervention (metformin and lifestyle) and control (placebo) arms. All models were adjusted for age, sex, ethnicity, and waist circumference at baseline (plus baseline ISI for 1-year ISI change models). A higher IR-GRS was associated with lower baseline ISI (β= -0.754 [SE=0.229] log-ISI per unit; P=0.001 in fully adjusted models). There was no differential effect of treatment for the association between IR-GRS on change in ISI; higher IR-GRS was associated with attenuation in ISI improvement over 1 year (β= -0.520 [SE=0.233]; P=0.03 in fully adjusted models; all treatment arms). Lifestyle intervention and metformin improved ISI, regardless of the genetic burden of IR-variants.
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| 5. |
- Ji, Yingjie, et al.
(författare)
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Genome-wide and abdominal MRI data provide evidence that a genetically determined favorable adiposity phenotype is characterized by lower ectopic liver fat and lower risk of type 2 diabetes, heart disease, and hypertension
- 2019
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 68:1, s. 207-219
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Tidskriftsartikel (refereegranskat)abstract
- Recent genetic studies have identified alleles associated with opposite effects on adiposity and risk of type 2 diabetes. We aimed to identify more of these variants and test the hypothesis that such favorable adiposity alleles are associated with higher subcutaneous fat and lower ectopic fat. We combined MRI data with genome-wide association studies of body fat percentage (%) and metabolic traits. We report 14 alleles, including 7 newly characterized alleles, associated with higher adiposity but a favorable metabolic profile. Consistent with previous studies, individuals carrying more favorable adiposity alleles had higher body fat % and higher BMI but lower risk of type 2 diabetes, heart disease, and hypertension. These individuals also had higher subcutaneous fat but lower liver fat and a lower visceral-to-subcutaneous adipose tissue ratio. Individual alleles associated with higher body fat % but lower liver fat and lower risk of type 2 diabetes included those in PPARG, GRB14, and IRS1, whereas the allele in ANKRD55 was paradoxically associated with higher visceral fat but lower risk of type 2 diabetes. Most identified favorable adiposity alleles are associated with higher subcutaneous and lower liver fat, a mechanism consistent with the beneficial effects of storing excess triglycerides in metabolically low-risk depots.
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| 6. |
- Kroeger, Janine, et al.
(författare)
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Circulating Fetuin-A and Risk of Type 2 Diabetes : A Mendelian Randomization Analysis
- 2018
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 67:6, s. 1200-1205
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Tidskriftsartikel (refereegranskat)abstract
- Fetuin-A, a hepatic-origin protein, is strongly positively associated with risk of type 2 diabetes in human observational studies, but it is unknown whether this association is causal. Weaimed to study the potential causal relation of circulating fetuin-A to risk of type 2 diabetes in a Mendelian randomization study with single nucleotide polymorphisms located in the fetuin-A-encoding AHSG gene. We used data from eight European countries of the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study including 10,020 incident cases. Plasma fetuin-A concentration was measured in a subset of 965 subcohort participants and 654 case subjects. A genetic score of the AHSG single nucleotide polymorphisms was strongly associated with fetuin-A (28% explained variation). Using the genetic score as instrumental variable of fetuin-A, we observed no significant association of a 50 mu g/mL higher fetuin-A concentration with diabetes risk (hazard ratio 1.02 [95% CI 0.97, 1.07]). Combining our results with those from the DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) consortium (12,171 case subjects) also did not suggest a clear significant relation of fetuin-A with diabetes risk. In conclusion, although there is mechanistic evidence for an effect of fetuin-A on insulin sensitivity and secretion, this study does not support a strong, relevant relationship between circulating fetuin-A and diabetes risk in the general population.
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| 7. |
- Manning, Alisa, et al.
(författare)
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A Low-Frequency Inactivating AKT2 Variant Enriched in the Finnish Population Is Associated With Fasting Insulin Levels and Type 2 Diabetes Risk
- 2017
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Ingår i: Diabetes. - : AMER DIABETES ASSOC. - 0012-1797 .- 1939-327X. ; 66:7, s. 2019-2032
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Tidskriftsartikel (refereegranskat)abstract
- To identify novel coding association signals and facilitate characterization of mechanisms influencing glycemic traits and type 2 diabetes risk, we analyzed 109,215 variants derived from exome array genotyping together with an additional 390,225 variants from exome sequence in up to 39,339 normoglycemic individuals from five ancestry groups. We identified a novel association between the coding variant (p.Pro50Thr) in AKT2 and fasting plasma insulin (FI), a gene in which rare fully penetrant mutations are causal for monogenic glycemic disorders. The low-frequency allele is associated with a 12% increase in FI levels. This variant is present at 1.1% frequency in Finns but virtually absent in individuals from other ancestries. Carriers of the FI-increasing allele had increased 2-h insulin values, decreased insulin sensitivity, and increased risk of type 2 diabetes (odds ratio 1.05). In cellular studies, the AKT2-Thr50 protein exhibited a partial loss of function. We extend the allelic spectrum for coding variants in AKT2 associated with disorders of glucose homeostasis and demonstrate bidirectional effects of variants within the pleckstrin homology domain of AKT2.
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| 8. |
- Norlin, Stefan, et al.
(författare)
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Asna1/TRC40 Controls beta-Cell Function and Endoplasmic Reticulum Homeostasis by Ensuring Retrograde Transport
- 2016
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 65:1, s. 110-119
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 diabetes (T2D) is characterized by insulin resistance and beta-cell failure. Insulin resistance per se, however, does not provoke overt diabetes as long as compensatory beta-cell function is maintained. The increased demand for insulin stresses the beta-cell endoplasmic reticulum (ER) and secretory pathway, and ER stress is associated with beta-cell failure in T2D. The tail recognition complex (TRC) pathway, including Asna1/TRC40, is implicated in the maintenance of endomembrane trafficking and ER homeostasis. To gain insight into the role of Asna1/TRC40 in maintaining endomembrane homeostasis and beta-cell function, we inactivated Asnal in beta-cells of mice. We show that Asna1 beta(-/-) mice develop hypoinsulinemia, impaired insulin secretion, and glucose intolerance that rapidly progresses to overt diabetes. Loss of Asnal function leads to perturbed plasma membrane-to-trans Golgi network and Golgi-to-ER retrograde transport as well as to ER stress in beta-cells. Of note, pharmacological inhibition of retrograde transport in isolated islets and insulinoma cells mimicked the phenotype of Asna1(beta-/-) beta-cells and resulted in reduced insulin content and ER stress. These data support a model where Asnal ensures retrograde transport and, hence, ER and insulin homeostasis in beta-cells.
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| 9. |
- Papandonatos, George D, et al.
(författare)
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Genetic Predisposition to Weight Loss and Regain With Lifestyle Intervention : Analyses From the Diabetes Prevention Program and the Look AHEAD Randomized Controlled Trials
- 2015
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 64:12, s. 4312-4321
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Tidskriftsartikel (refereegranskat)abstract
- Clinically relevant weight loss is achievable through lifestyle modification, but unintentional weight regain is common. We investigated whether recently discovered genetic variants affect weight loss and/or weight regain during behavioral intervention. Participants at high-risk of type 2 diabetes (Diabetes Prevention Program [DPP]; N = 917/907 intervention/comparison) or with type 2 diabetes (Look AHEAD [Action for Health in Diabetes]; N = 2,014/1,892 intervention/comparison) were from two parallel arm (lifestyle vs. comparison) randomized controlled trials. The associations of 91 established obesity-predisposing loci with weight loss across 4 years and with weight regain across years 2-4 after a minimum of 3% weight loss were tested. Each copy of the minor G allele of MTIF3 rs1885988 was consistently associated with greater weight loss following lifestyle intervention over 4 years across the DPP and Look AHEAD. No such effect was observed across comparison arms, leading to a nominally significant single nucleotide polymorphism x treatment interaction (P = 4.3 x 10-3). However, this effect was not significant at a study-wise significance level (Bonferroni threshold P < 5.8 x 10-4). Most obesity-predisposing gene variants were not associated with weight loss or regain within the DPP and Look AHEAD trials, directly or via interactions with lifestyle.
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| 10. |
- Scott, Robert A., et al.
(författare)
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An Expanded Genome-Wide Association Study of Type 2 Diabetes in Europeans
- 2017
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 66:11, s. 2888-2902
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Tidskriftsartikel (refereegranskat)abstract
- To characterize type 2 diabetes (T2D)-associated variation across the allele frequency spectrum, we conducted a meta-analysis of genome-wide association data from 26,676 T2D case and 132,532 control subjects of European ancestry after imputation using the 1000 Genomes multiethnic reference panel. Promising association signals were followed up in additional data sets (of 14,545 or 7,397 T2D case and 38,994 or 71,604 control subjects). We identified 13 novel T2D-associated loci (P < 5 x 10(-8)), including variants near the GLP2R, GIP, and HLA-DQA1 genes. Our analysis brought the total number of independent T2D associations to 128 distinct signals at 113 loci. Despite substantially increased sample size and more complete coverage of low-frequency variation, all novel associations were driven by common single nucleotide variants. Credible sets of potentially causal variants were generally larger than those based on imputation with earlier reference panels, consistent with resolution of causal signals to common risk haplotypes. Stratification of T2D-associated loci based on T2D-related quantitative trait associations revealed tissue-specific enrichment of regulatory annotations in pancreatic islet enhancers for loci influencing insulin secretion and in adipocytes, monocytes, and hepatocytes for insulin action-associated loci. These findings highlight the predominant role played by common variants of modest effect and the diversity of biological mechanisms influencing T2D pathophysiology.
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