| 1. |
- Bandstein, Marcus, 1988-, et al.
(författare)
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A genetic risk score is associated with weight loss following Roux-Y gastric bypass surgery
- 2016
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Ingår i: Obesity Surgery. - : Springer Science and Business Media LLC. - 0960-8923 .- 1708-0428. ; 26:9, s. 2183-2189
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Tidskriftsartikel (refereegranskat)abstract
- Currently, Roux-en Y gastric bypass (RYGB) is the most efficient therapy for severe obesity. Weight loss after surgery is, however, highly variable and genetically influenced. Genome-wide association studies have identified several single nucleotide polymorphisms (SNP) associated with body mass index (BMI) and waist-hip ratio (WHR). We aimed to identify two genetic risk scores (GRS) composed of weighted BMI and WHR-associated SNPs to estimate their impact on excess BMI loss (EBMIL) after RYGB surgery. Two hundred and thirty-eight obese patients (BMI 45.1 +/- 6.2 kg/m(2), 74 % women), who underwent RYGB, were genotyped for 35 BMI and WHR-associated SNPs and were followed up after 2 years. SNPs with high impact on post-surgical weight loss were filtered out using a random forest model. The filtered SNPs were combined into a GRS and analyzed in a linear regression model. An up to 11 % lower EBMIL with higher risk score was estimated for two GRS models (P = 0.026 resp. P = 0.021) composed of seven BMI-associated SNPs (closest genes: MC4R, TMEM160, PTBP2, NUDT3, TFAP2B, ZNF608, MAP2K5, GNPDA2, and MTCH2) and of three WHR-associated SNPs (closest genes: HOXC13, LYPLAL1, and DNM3-PIGC). Patients within the lowest GRS quartile had higher EBMIL compared to patients within the other three quartiles in both models. We identified two GRSs composed of BMI and WHR-associated SNPs with significant impact on weight loss after RYGB surgery using random forest analysis as a SNP selection tool. The GRS may be useful to pre-surgically evaluate the risks for patients undergoing RYGB surgery.
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| 2. |
- Ciuculete, Diana-Maria, et al.
(författare)
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A genetic risk score is significantly associated with statin therapy response in the elderly population
- 2017
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Ingår i: Clinical Genetics. - : Wiley. - 0009-9163 .- 1399-0004. ; 91:3, s. 379-385
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Tidskriftsartikel (refereegranskat)abstract
- The ability of statins to strongly reduce low-density lipoprotein cholesterol (LDL-C) varies interindividually and is partially influenced by genetic variants. Based on a comprehensive analysis of 23 single nucleotide polymorphisms (SNPs) known to be associated with pharmacokinetics and dynamics of statins, we developed a genetic risk score to study its impact on the therapy outcome in elderly individuals under at least 5 years statin therapy. The study was performed in a population-based cohort of 1016 elderly individuals, which comprised 168 statin users investigated at age 75 and 80. Using random forest models, the major variants influencing LDL-C levels were summarized in a weighted GRS (wGRS). The wGRS was tested with lipid and glucose outcomes and validated in an independent population-based cohort including 221 statin users. Four SNPs within the APOE cluster (rs7412, rs4420638), ABCC2 (rs2002042) and CELSR/SORT1/PSRC1 (rs646776), displayed a major impact on statin efficacy. The wGRS was significantly associated with lower LDL-C at age 75 and 80. This association was replicated displaying similar results. GRS analysis is a powerful tool to evaluate the additive effects of genetic variants on statin response and to estimate the magnitude of LDL-C reduction to a considerable extent in the older population.
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| 3. |
- Nilsson, Emil, et al.
(författare)
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Roux-En Y Gastric Bypass Surgery Induces Genome-Wide Promoter-Specific Changes in DNA Methylation in Whole Blood of Obese Patients
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- ContextDNA methylation has been proposed to play a critical role in many cellular and biological processes.ObjectiveTo examine the influence of Roux-en-Y gastric bypass (RYGB) surgery on genome-wide promoter-specific DNA methylation in obese patients. Promoters are involved in the initiation and regulation of gene transcription.MethodsPromoter-specific DNA methylation in whole blood was measured in 11 obese patients (presurgery BMI >35 kg/m2, 4 females), both before and 6 months after RYGB surgery, as well as once only in a control group of 16 normal-weight men. In addition, body weight and fasting plasma glucose were measured after an overnight fast.ResultsThe mean genome-wide distance between promoter-specific DNA methylation of obese patients at six months after RYGB surgery and controls was shorter, as compared to that at baseline (p<0.001). Moreover, postsurgically, the DNA methylation of 51 promoters was significantly different from corresponding values that had been measured at baseline (28 upregulated and 23 downregulated, P<0.05 for all promoters, Bonferroni corrected). Among these promoters, an enrichment for genes involved in metabolic processes was found (n = 36, P<0.05). In addition, the mean DNA methylation of these 51 promoters was more similar after surgery to that of controls, than it had been at baseline (P<0.0001). When controlling for the RYGB surgery-induced drop in weight (-24% of respective baseline value) and fasting plasma glucose concentration (-16% of respective baseline value), the DNA methylation of only one out of 51 promoters (~2%) remained significantly different between the pre-and postsurgery time points.ConclusionsEpigenetic modifications are proposed to play an important role in the development of and predisposition to metabolic diseases, including type II diabetes and obesity. Thus, our findings may form the basis for further investigations to unravel the molecular effects of gastric bypass surgery.Clinical TrialClinicalTrials.gov NCT01730742
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| 4. |
- Olivo, Gaia, MD, 1989-
(författare)
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Brain Structure and Function in Adolescents with Atypical Anorexia Nervosa
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Atypical anorexia nervosa (AAN) has a high incidence in adolescents, resulting in significant morbidity and mortality. The weight loss is generally less pronounced than that experienced in full-syndrome anorexia nervosa (AN), but the medical consequences can be as severe. Neuroimaging could improve our knowledge regarding the pathogenesis of eating disorders, however research on adolescents is limited, and no neuroimaging studies have been conducted in AAN. In paper I, we investigated brain structure through a voxel-based morphometry analysis in 22 drug-naïve adolescent females newly-diagnosed with AAN, and 38 age- and sex-matched healthy controls. In Paper II, we investigated white matter microstructural integrity on 25 drug-naïve adolescent patients with AAN and 25 healthy controls, using diffusion tensor imaging with a tract-based spatial statistics approach. No differences in brain structure could be detected, indicating preserved regional grey matter volumes and white matter diffusivity in patients with AAN compared to controls. These findings suggest that previous observations of brain structure alterations in full syndrome AN may constitute state-related consequences of severe underweight. Alternatively, the preservation of brain structure might indeed differentiate AAN from AN. In paper III, we investigated resting-state functional connectivity in 22 drug-naïve adolescent patients with AAN, and 24 healthy controls. We report reduced connectivity in patients in brain areas involved in face-processing and social cognition, while an increased connectivity, correlating with depressive symptoms, was found in areas involved in the multimodal integration of sensory stimuli, aesthetic judgment, and social rejection anxiety. These findings point toward a core role for an altered development of socio-emotional skills in the pathogenesis of AAN. In Paper IV, we investigated neural connectivity underlying visual processing of foods with different caloric content in a sample of 28 adolescent females diagnosed with AAN, and 33 age- and sex-matched healthy controls. Our results showed higher connectivity in patients in pathways related to the integration of sensory input and memory retrieval, in response to food with high caloric content. This, however, was coupled to lower connectivity in salience and attentional networks, and lower connectivity between areas involved in visual food cues processing and appetite regulatory regions. Thus, despite food with high caloric content is associated to greater processing of somatosensory information in patients, it is attributed less salience and engages patients’ attention less than food with low caloric content.
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