| 1. |
- Falchi, M., et al.
(författare)
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Low copy number of the salivary amylase gene predisposes to obesity
- 2014
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 46:5, s. 492-497
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Tidskriftsartikel (refereegranskat)abstract
- Common multi-allelic copy number variants (CNVs) appear enriched for phenotypic associations compared to their biallelic counterparts. Here we investigated the influence of gene dosage effects on adiposity through a CNV association study of gene expression levels in adipose tissue. We identified significant association of a multi-allelic CNV encompassing the salivary amylase gene (AMY1) with body mass index (BMI) and obesity, and we replicated this finding in 6,200 subjects. Increased AMY1 copy number was positively associated with both amylase gene expression (P = 2.31 × 10-14) and serum enzyme levels (P < 2.20 × 10-16), whereas reduced AMY1 copy number was associated with increased BMI (change in BMI per estimated copy =-0.15 (0.02) kg/m 2; P = 6.93 × 10-10) and obesity risk (odds ratio (OR) per estimated copy = 1.19, 95% confidence interval (CI) = 1.13-1.26; P = 1.46 × 10-10). The OR value of 1.19 per copy of AMY1 translates into about an eightfold difference in risk of obesity between subjects in the top (copy number > 9) and bottom (copy number < 4) 10% of the copy number distribution. Our study provides a first genetic link between carbohydrate metabolism and BMI and demonstrates the power of integrated genomic approaches beyond genome-wide association studies. © 2014 Nature America, Inc. All rights reserved.
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| 2. |
- Andersson-Assarsson, Johanna C., 1974, et al.
(författare)
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Evolution of age-related mutation-driven clonal haematopoiesis over 20 years is associated with metabolic dysfunction in obesity
- 2023
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Ingår i: Ebiomedicine. - 2352-3964. ; 92
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Tidskriftsartikel (refereegranskat)abstract
- Background Haematopoietic clones caused by somatic mutations with >= 2% variant allele frequency (VAF) increase with age and are linked to risk of haematological malignancies and cardiovascular disease. Recent observations suggest that smaller clones (VAF<2%) are also associated with adverse outcomes. Our aims were to determine the prevalence of clonal haematopoiesis driven by clones of variable sizes in individuals with obesity treated by usual care or bariatric surgery (a treatment that improves metabolic status), and to examine the expansion of clones in relation to age and metabolic dysregulation over up to 20 years.Methods Clonal haematopoiesis-driver mutations (CHDMs) were identified in blood samples from participants of the Swedish Obese Subjects intervention study. Using an ultrasensitive assay, we analysed single-timepoint samples from 1050 individuals treated by usual care and 841 individuals who had undergone bariatric surgery, and multiple-timepoint samples taken over 20 years from a subset (n = 40) of the individuals treated by usual care.Findings In this explorative study, prevalence of CHDMs was similar in the single-timepoint usual care and bariatric surgery groups (20.6% and 22.5%, respectively, P = 0.330), with VAF ranging from 0.01% to 31.15%. Clone sizes increased with age in individuals with obesity, but not in those who underwent bariatric surgery. In the multiple-timepoint analysis, VAF increased by on average 7% (range -4% to 24%) per year and rate of clone growth was negatively associated with HDL-cholesterol (R = -0.68, 1.74 E-04).Interpretation Low HDL-C was associated with growth of haematopoietic clones in individuals with obesity treated by usual care.
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| 3. |
- Moustafa, J. S. E., et al.
(författare)
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Novel association approach for variable number tandem repeats (VNTRs) identifies DOCK5 as a susceptibility gene for severe obesity
- 2012
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 21:16, s. 3727-3738
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Tidskriftsartikel (refereegranskat)abstract
- Variable number tandem repeats (VNTRs) constitute a relatively under-examined class of genomic variants in the context of complex disease because of their sequence complexity and the challenges in assaying them. Recent large-scale genome-wide copy number variant mapping and association efforts have highlighted the need for improved methodology for association studies using these complex polymorphisms. Here we describe the in-depth investigation of a complex region on chromosome 8p21.2 encompassing the dedicator of cytokinesis 5 (DOCK5) gene. The region includes two VNTRs of complex sequence composition which flank a common 3975 bp deletion, all three of which were genotyped by polymerase chain reaction and fragment analysis in a total of 2744 subjects. We have developed a novel VNTR association method named VNTRtest, suitable for association analysis of multi-allelic loci with binary and quantitative outcomes, and have used this approach to show significant association of the DOCK5 VNTRs with childhood and adult severe obesity (P-empirical 8.9 10(8) and P 3.1 10(3), respectively) which we estimate explains approximate to 0.8 of the phenotypic variance. We also identified an independent association between the 3975 base pair (bp) deletion and obesity, explaining a further 0.46 of the variance (P-combined 1.6 10(3)). Evidence for association between DOCK5 transcript levels and the 3975 bp deletion (P 0.027) and both VNTRs (P-empirical 0.015) was also identified in adipose tissue from a Swedish family sample, providing support for a functional effect of the DOCK5 deletion and VNTRs. These findings highlight the potential role of DOCK5 in human obesity and illustrate a novel approach for analysis of the contribution of VNTRs to disease susceptibility through association studies.
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| 4. |
- Ahlin, Sofie, 1985, et al.
(författare)
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Macrophage Gene Expression in Adipose Tissue is Associated with Insulin Sensitivity and Serum Lipid Levels Independent of Obesity.
- 2013
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Ingår i: Obesity (Silver Spring, Md.). - : Wiley. - 1930-739X .- 1930-7381. ; 21:12
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Obesity is linked to both increased metabolic disturbances and increased adipose tissue macrophage infiltration. However, whether macrophage infiltration directly influences human metabolism is unclear. The aim of this study was to investigate if there are obesity-independent links between adipose tissue macrophages and metabolic disturbances. Design and Methods: Expression of macrophage markers in adipose tissue was analyzed by DNA microarrays in the SOS Sib Pair study and in patients with type 2 diabetes and a BMI-matched healthy control group. Results: The expression of macrophage markers in adipose tissue was increased in obesity and associated with several metabolic and anthropometric measurements. After adjustment for BMI, the expression remained associated with insulin sensitivity, serum levels of insulin, C-peptide, high density lipoprotein cholesterol (HDL-cholesterol) and triglycerides. In addition, the expression of most macrophage markers was significantly increased in patients with type 2 diabetes compared to the control group. Conclusion: Our study shows that infiltration of macrophages in human adipose tissue, estimated by the expression of macrophage markers, is increased in subjects with obesity and diabetes and associated with insulin sensitivity and serum lipid levels independent of BMI. This indicates that adipose tissue macrophages may contribute to the development of insulin resistance and dyslipidemia.
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| 5. |
- Shulman, Alexander, 1978, et al.
(författare)
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Incidence of end-stage renal disease following bariatric surgery in the Swedish Obese Subjects Study.
- 2018
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Ingår i: International journal of obesity. - : Springer Science and Business Media LLC. - 1476-5497 .- 0307-0565. ; 42, s. 964-973
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is a major public health problem leading to co-morbidities such as diabetes, hypertension and kidney failure. Bariatric surgery results in pronounced and maintained weight loss and prevention of obesity-related diseases and their complications. Most studies of bariatric surgery on kidney disease show improvements after surgery. However, long-term studies analyzing hard end-points are lacking. Here we report on the long-term effects of bariatric surgery compared to usual obesity care on incidence of end-stage renal disease (ESRD) alone and in combination with chronic kidney disease stage 4 (CKD4/ESRD).4047 patients were included in the Swedish Obese Subjects (SOS) study. Inclusion criteria were age 37-60 years and BMI≥34 in men and BMI≥38 in women. Patients in the bariatric surgery group (N=2010) underwent banding (18%), vertical banded gastroplasty (69%), or gastric bypass (13%); controls (N=2037) received usual obesity care. In this analysis, patients were followed up for a median time of 18 years. The incidence of ESRD and CKD4 was obtained by crosschecking the SOS database with the Swedish National Patient Register.During follow-up, ESRD occurred in 13 patients in the surgery group and in 26 patients in the control group (adjusted hazard ratio (HR)=0.27; 95% CI 0.12-0.60; p=0.001). The number of CKD4/ESRD events was 23 in the surgery group and 39 in the control group (adjusted HR=0.33; 95% CI 0.18-0.62; p<0.001). In both analyses, bariatric surgery had a more favorable effect in patients with baseline serum insulin levels above median compared to those with lower insulin levels (interaction p=0.010). Treatment benefit of bariatric surgery was also greater in patients with macroalbuminuria at baseline compared to those without macroalbuminuria (interaction p<0.001).Our study showed for the first time that bariatric surgery is associated with a long-term protection against ESRD and CKD4/ESRD.
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| 6. |
- Zhang, Yuan, et al.
(författare)
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Adiponectin Associates with Rheumatoid Arthritis Risk in Overweight and Obesity Independently of Other Adipokines
- 2021
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Ingår i: Journal of Clinical Medicine. - : MDPI AG. - 2077-0383. ; 10:13
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Tidskriftsartikel (refereegranskat)abstract
- We recently reported that increased serum adiponectin was associated with rheumatoid arthritis (RA) risk in subjects with obesity. We hereby aim to determine if other adipokines associate with RA risk and if the association between adiponectin and RA is independent of other adipokines. Two nested-case control studies were performed in two different cohorts: 82 participants of the Swedish Obese Subjects (SOS) study who developed RA during follow-up matched with 410 controls, and 88 matched pairs from the Medical Biobank of Northern Sweden. Baseline levels of circulating adipokines were measured using ELISA. In a multivariable analysis in the SOS cohort, higher adiponectin was associated with an increased risk of RA independently of other adipokines (OR for RA risk: 1.06, 95% CI: 1.01-1.12, p = 0.02). No association between leptin, resistin, and visfatin levels and the risk of RA was detected. In the cohort from the Medical Biobank of Northern Sweden, higher adiponectin was associated with an increased risk of RA only in participants with overweight/obesity (OR: 1.17, 95% CI: 1.01-1.36, p = 0.03), independently of other adipokines. Our results show that in individuals with overweight/obesity, higher circulating levels of adiponectin, but not leptin, resistin, or visfatin, were associated with an increased RA risk.
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| 7. |
- Zhang, Y, et al.
(författare)
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Elevated adiponectin predicts the development of rheumatoid arthritis in subjects with obesity
- 2020
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Ingår i: Scandinavian Journal of Rheumatology. - : Informa UK Limited. - 0300-9742 .- 1502-7732. ; 49:6, s. 452-460
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the current study is to determine whether baseline serum adiponectin levels predict the development of rheumatoid arthritis (RA). Method: The current report includes 3693 individuals from the Swedish Obese Subjects (SOS) study. The original SOS study is a longitudinal non-randomized controlled study aiming to assess the effect of bariatric surgery on obesity-related mortality and morbidity. Participants included in the present report had adiponectin measurement available at baseline and no prevalent RA. The diagnosis of RA was retrieved through the Swedish National Patient Register. Results: During a follow-up for up to 29years, 82 study participants developed RA. Elevated baseline adiponectin levels were associated with a higher risk of developing RA independently of other factors, including C-reactive protein (CRP) and smoking [hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.12–2.60 for an increase in adiponectin of 10 mg/L, p =0.01]. After stratifying the population according to adiponectin and CRP median at baseline, study participants with both adiponectin and CRP above the median had a higher risk of developing RA compared to subjects with adiponectin and CRP below the median (HR 2.80, 95% CI 1.25–6.31, p =0.01). Conclusions: In this cohort of subjects with obesity followed up for up to 29years, high serum adiponectin levels at baseline were associated with an increased risk for RA. Moreover, subjects with both high adiponectin and CRP levels at baseline were at particular risk of developing RA. ClinicalTrials.gov Identifier: NCT01479452. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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| 8. |
- Ahlin, Sofie, 1985, et al.
(författare)
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Fracture risk after three bariatric surgery procedures in Swedish obese subjects : up to 26 years follow-up of a controlled intervention study
- 2020
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 287:5, s. 546-557
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies have reported an increased fracture risk after bariatric surgery. Objective: To investigate the association between different bariatric surgery procedures and fracture risk. Methods: Incidence rates and hazard ratios for fracture events were analysed in the Swedish Obese Subjects study; an ongoing, nonrandomized, prospective, controlled intervention study. Hazard ratios were adjusted for risk factors for osteoporosis and year of inclusion. Information on fracture events were captured from the Swedish National Patient Register. The current analysis includes 2007 patients treated with bariatric surgery (13.3% gastric bypass, 18.7% gastric banding, and 68.0% vertical banded gastroplasty) and 2040 control patients with obesity matched on group level based on 18 variables. Median follow-up was between 15.1 and 17.9 years for the different treatment groups. Results: During follow-up, the highest incidence rate for first-time fracture was observed in the gastric bypass group (22.9 per 1000 person-years). The corresponding incidence rates were 10.4, 10.7 and 9.3 per 1000 person-years for the vertical banded gastroplasty, gastric banding and control groups, respectively. The risk of fracture was increased in the gastric bypass group compared with the control group (adjusted hazard ratio [adjHR] 2.58; 95% confidence interval [CI] 2.02–3.31; P < 0.001), the gastric banding group (adjHR 1.99; 95%CI 1.41–2.82; P < 0.001), and the vertical banded gastroplasty group (adjHR 2.15; 95% CI 1.66–2.79; P < 0.001). Conclusions: The risk of fracture is increased after gastric bypass surgery. Our findings highlight the need for long-term follow-up of bone health for patients undergoing this treatment.
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| 9. |
- Anveden, Åsa, et al.
(författare)
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Long-term incidence of female-specific cancer after bariatric surgery or usual care in the Swedish Obese Subjects Study
- 2017
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Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258. ; 145:2, s. 224-229
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To examine the long-term effects of bariatric surgery on female-specific cancer in women with obesity. Methods. The prospective, matched Swedish Obese Subjects (SOS) study was designed to examine outcomes after bariatric surgery. This study includes 1420 women from the SOS cohort that underwent bariatric surgery and 1447 contemporaneously matched controls who received conventional obesity treatment. Age was 3760 years and BMI was >= 38 kg/m(2). Information on cancer events was obtained from the Swedish National Cancer Registry. Median follow-up time was 18.1 years (interquartile range 14.8-20.9 years, maximum 26 years). This study is registered with ClinicalTrials.gov, NCT01479452. Results. Bariatric surgery was associated with reduced risk of overall cancer (hazard ratio = 0.71; 95% CI 0.59-0.85; p < 0.001). About half of the observed cancers were female-specific, and the incidence of these were lower in the surgery group compared with the control group (hazard ratio = 0.68; 95% CI 0.52-0.88; p = 0.004). The surgical treatment benefit with respect to female-specific cancer was significantly associated with baseline serum insulin (interaction p value = 0.022), with greater relative treatment benefit in patients with medium or high insulin levels. Separate analyses of different types of female-specific cancers showed that bariatric surgery was associated with reduced risk of endometrial cancer (hazard ratio = 0.56: 95% CI 035-0.89; p = 0.014). Conclusions. In this long-term study, bariatric surgery was associated with reduced risk of female-specific cancer, especially in women with hyperinsulinemia at baseline.
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| 10. |
- Byman, Elin, et al.
(författare)
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Alpha-amylase 1A copy number variants and the association with memory performance and Alzheimer's dementia
- 2020
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Ingår i: Alzheimers Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Previous studies have shown that copy number variation (CNV) in the alpha (alpha)-amylase gene (AMY1A) is associated with body mass index, insulin resistance, and blood glucose levels, factors also shown to increase the risk of Alzheimer's dementia (AD). We have previously demonstrated the presence of alpha-amylase in healthy neuronal dendritic spines and a reduction of the same in AD patients. In the current study, we investigate the relationship between AMY1A copy number and AD, memory performance, and brain alpha-amylase activity. Methods and materials The association between AMY1A copy number and development of AD was analyzed in 5422 individuals (mean age at baseline 57.5 +/- 5.9, females 58.2%) from the Malmo diet and cancer study genotyped for AMY1A copy number, whereof 247 where diagnosed with AD during a mean follow-up of 20 years. Associations between AMY1A copy number and cognitive performance where analyzed in 791 individuals (mean age at baseline 54.7 +/- 6.3, females 63%), who performed Montreal Cognitive Assessment (MoCA) test. Correlation analysis between alpha-amylase activity or alpha-amylase gene expression and AMY1A copy number in post-mortem hippocampal tissue from on demented controls (n = 8) and AD patients (n = 10) was also performed. Results Individuals with very high ( >= 10) AMY1A copy number had a significantly lower hazard ratio of AD (HR = 0.62, 95% CI 0.41-0.94) and performed significantly better on MoCA delayed word recall test, compared to the reference group with AMY1A copy number 6. A trend to lower hazard ratio of AD was also found among individuals with low AMY1A copy number (1-5) (HR = 0.74, 95% CI 0.53-1.02). A tendency towards a positive correlation between brain alpha-amylase activity and AMY1A copy number was found, and females showed higher brain alpha-amylase activity compared to males. Conclusion Our study suggests that the degree of alpha-amylase activity in the brain is affected by AMY1A copy number and gender, in addition to AD pathology. The study further suggests that very high AMY1A copy number is associated with a decreased hazard ratio of AD and we speculate that this effect is mediated via a beneficial impact of AMY1A copy number on episodic memory performance.
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