| 1. |
- Garg, Gaurav, et al.
(författare)
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Variation in the MC4R Gene Is Associated with Bone Phenotypes in Elderly Swedish Women.
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is characterized by reduced bone mineral density (BMD) and increased fracture risk. Fat mass is a determinant of bone strength and both phenotypes have a strong genetic component. In this study, we examined the association between obesity associated polymorphisms (SNPs) with body composition, BMD, Ultrasound (QUS), fracture and biomarkers (Homocysteine (Hcy), folate, Vitamin D and Vitamin B12) for obesity and osteoporosis. Five common variants: rs17782313 and rs1770633 (melanocortin 4 receptor (MC4R); rs7566605 (insulin induced gene 2 (INSIG2); rs9939609 and rs1121980 (fat mass and obesity associated (FTO) were genotyped in 2 cohorts of Swedish women: PEAK-25 (age 25, n = 1061) and OPRA (age 75, n = 1044). Body mass index (BMI), total body fat and lean mass were strongly positively correlated with QUS and BMD in both cohorts (r(2) = 0.2-0.6). MC4R rs17782313 was associated with QUS in the OPRA cohort and individuals with the minor C-allele had higher values compared to T-allele homozygotes (TT vs. CT vs.
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| 2. |
- Kumar, Jitender, et al.
(författare)
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Associations of Body Mass Index and Obesity-Related Genetic Variants with Serum Metabolites
- 2014
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Ingår i: Current Metabolomics. - 2213-235X. ; 2:1, s. 27-36-
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Body mass index (BMI) is one of the most important risk factors for different metabolic and cardiovascular disorders. Previously, both genetic and environmental agents associated with BMI have been described. The main focus of this exploratory study was to find the circulating metabolites associated with BMI utilizing an untargeted metabolomics approach. Additionally, significant metabolites identified were studied for their relation with BMIassociated single nucleotide polymorphisms (SNPs). Materials and Methods: A total of 971 individuals from the Cancer of the Prostate in Sweden study (discovery sample- 275 prostate cancers patients and 182 controls; replication sample- 514 prostate cancer patients) were utilized. Blood samples were collected and serum metabolic profiling was obtained using ultra-performance liquid chromatography followed by mass spectrometry. Genotyping data was available for 26 out of 32 SNPs (21 genotyped and 5 proxies) previously robustly associated with BMI in individuals of European descent. Weighted genetic risk score was generated using these SNPs and studied for its association with metabolites. Results: A total of 6138 and 5209 metabolite features were detected in discovery and replication samples, respectively. Out of 6138 metabolite features in discovery sample, 201 were found to be significantly associated with BMI (p<8.15*10-6) after multiple testing correction. These 201 features were further investigated in the replication samples and 16 were found to be significantly associated with BMI (p<2.49*10-4). Seven of these significant features were isotopes for four of the primary metabolites. Four metabolites were putatively identified: monoacylglyceride (18:1), diacylglyrcerol (32:1) and two phosphatidylcholines (34:0 and 36:0). Weighted genetic score of BMI-associated SNPs was not associated with these four metabolites. Conclusion: Four identifiable metabolites (monoacylglyceride, diacyclglyrcerol and two phosphatidylcholines) were found to be significantly associated with BMI in both discovery and replication samples. Common variants associated with BMI did not show association with these four metabolites. - See more at: http://www.eurekaselect.com/120422/article#sthash.PgqffHqv.dpuf
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| 3. |
- Kumar, Jitender, et al.
(författare)
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Influence of persistent organic pollutants on oxidative stress in population-based samples
- 2014
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 114, s. 303-309
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants (POPs) are a large group of chemicals widely used and produced in various industrial applications. Many cell culture/animal studies have shown that POPs can induce oxidative stress. Since such data is lacking in humans, we conducted a large population-based study to analyze associations between POPs and oxidative stress markers. We measured following POPs; 16 polychlorinated biphenyls (PCBs), 5 organochlorine (OC) pesticides, octachlorinated dibenzo-p-dioxin, and polybrominated diphenyl ether 47, and oxidative stress markers; homocysteine, reduced [GSH] and oxidized glutathione [GSSG], glutathione ratio [GSSG/GSH], total glutathione, oxidized low-density lipoprotein [ox-LDL], ox-LDL antibodies, conjugated dienes, baseline conjugated dienes of LDL, and total anti-oxidative capacity in plasma samples collected from 992 70-year old individuals (50% women) from the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. Linear regression analyses were performed to study the associations between oxidative stress markers and summary measures of POPs including the total toxic equivalence (TEQ), sums of PCBs and BC pesticides (main exposures) while adjusting for potential confounders. In multivariable-adjusted analyses, sum of PCBs showed strong associations with ox-LDL (beta = 0.94; P = 2.9 * 10(-6)). Further, sum of PCBs showed association with glutathione-related markers (GSSG: beta = 0.01; P = 6.0 *10(-7); GSSG/GSH: beta = 0.002; P = 9.7 * 10(-10)), although in reverse direction. Other summary measures did not show any significant association with these markers. In our study of elderly individuals from the general population, we show that plasma levels of POPs are associated with markers of increased oxidative stress thereby suggesting that even low dose background exposure to POPs may be involved in oxidative stress. (C) 2014 Elsevier Ltd. All rights reserved.
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| 4. |
- Kumar, Jitender, et al.
(författare)
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Influence of persistent organic pollutants on the complement system in a population-based human sample
- 2014
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 71, s. 94-100
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Tidskriftsartikel (refereegranskat)abstract
- Background: Persistent organic pollutants (POPS) are toxic compounds generated through various industrial activities and have adverse effects on human health. Studies performed in cell cultures and animals have revealed that POPs can alter immune-system functioning. The complement system is part of innate immune system that helps to clear pathogens from the body. We performed a large-scale population-based study to find out associations between summary measures of different POPs and different complement system markers.Methods: In this cross-sectional study, 16 polychlorinated biphenyls (PCBs), 3 organochlorine (OC) pesticides, octachloro-p-dibenzodioxin, and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) were analyzed for their association with levels of protein complement 3 (C3), 3a (C3a), 4 (C4) and C3a/C3 ratio. A total of 992 individuals (all aged 70 years, 50% females) were recruited from the Prospective Investigation of the Vasculature in Uppsala Seniors cohort. Regression analysis adjusting for a variety of confounders was performed to study the associations of different POP exposures (total toxic equivalency value or TEQ and sum of 16 PCBs) with protein complements.Results: The TEQ values were found to be positively associated with C3a (beta = 0.07, 95% CI = 0.017-0.131, p = 0.01) and C3a/C3 ratio (beta = 0.07, 95% Cl = 0.015-0.126, p = 0.01) taking possible confounders into account. The association observed was mainly driven by PCB-126.Conclusion: In this study involving 992 elderly individuals from the general population, we showed that POPs, mainly PCB-126, were associated with levels of complement system markers indicating that the association of these toxic compounds with downstream disease could be mediated by activation of immune system. (C) 2014 Elsevier Ltd. All rights reserved.
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| 5. |
- Kumar, Jitender, et al.
(författare)
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Persistent Organic Pollutants and Inflammatory Markers in a Cross-Sectional Study of Elderly Swedish People : The PIVUS Cohort
- 2014
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Ingår i: Journal of Environmental Health Perspectives. - : National Institute of Environmental Health Science. - 0091-6765 .- 1552-9924. ; 122:9, s. 977-983
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Persistent organic pollutants (POPs) are compounds that are generated through various industrial activities and released in the surrounding environment. Different animal studies have shown effects of different POPs on various inflammatory markers.OBJECTIVE: Because very few studies have been conducted in humans, we assessed the associations between different POPs and inflammatory markers in a large population-based sample of elderly men and women (all 70 years of age) from Sweden.METHODS: This cross-sectional study investigated the concentrations of several polychlorinated biphenyls (PCBs), organochlorine pesticides, polychlorinated dibenzo-p-dioxin, and brominated diphenyl ether congeners and their association with a number of inflammatory markers [vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), E-selectin, C-reactive protein (CRP), total leucocyte count, tumor necrosis factor alpha (TNF-alpha), monocyte chemotactic protein 1 (MCP-1), and interleukin 6 (IL-6)] in 992 individuals. These individuals were recruited from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. We used a total toxic equivalency (TEQ) value that measures toxicological effects with the relative potencies of various POPs.RESULTS: Following adjustment for potential confounders, the TEQ value (driven mainly by PCB-126) was significantly associated with levels of ICAM-1 (p < 10(-5)). A similar trend was also observed between sum of PCBs and VCAM-1 (p < 0.001). No significant associations were observed between levels of POPs and other inflammatory markers.CONCLUSIONS: TEQ values were associated with levels of ICAM-1, to a lesser degree also with VCAM-1, but not with CRP and several other inflammatory markers. These findings suggest an activation of vascular adhesion molecules by POPs, and particularly by PCB-126.
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| 6. |
- Kumar, Jitender, et al.
(författare)
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Persistent organic pollutants and liver dysfunction biomarkers in a population-based human sample of men and women
- 2014
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Ingår i: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 134, s. 251-256
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective: Persistent organic pollutants (POPs) are stable organic compounds generated through different industrial activities. Liver is involved in the metabolism of POPs, and hence exposure to POPs may interfere with liver function. Although a few studies have shown adverse effects of POPs on liver function, large-scale studies involving humans are lacking. We performed this large population-based cross-sectional study to assess the associations between different POPs and liver dysfunction biomarkers.Methods: A total of 992 individuals (all aged 70 years, 50% males) were recruited as part of Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. The total toxic equivalency (TEQ) value was calculated for seven mono-ortho and two non-ortho substituted polychlorinated biphenyls (PCBs) and octachloro-p-dibenzodioxin (OCDD) to assess their toxicological effects. The association of TEQ values, summary measures of 16 PCBs (sum of PCBs) and three organochlorine pesticides (sum of OC pesticides) with liver dysfunction biomarkers (bilirubin; alkaline phosphatase, ALP; alanine amino-transferase, ALT; and gamma-glutamyltransferase, GGT) was analyzed utilizing linear regression analysis.Results: The mono-ortho PCB TEQ values were found to be significantly positively associated with bilirubin (beta=0.71, P=0.008), while sum of OC pesticide concentrations was negatively associated with ALP (beta= -0.02, P=0.002) after adjusting for various potential confounders. When analyzed individually, a number of different POPs were associated with ALP, ALT and bilirubin. No such association with GGT was observed.Conclusion: Various POPs including PCBs, OCDD and pesticides were associated with the liver dysfunction biomarkers bilirubin, ALT and ALP, suggesting adverse effects on liver function from these environmental pollutants. (C) 2014 Elsevier Inc. All rights reserved.
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