| 11. |
- Gielen, Marij, et al.
(author)
-
Body mass index is negatively associated with telomere length : A collaborative cross-sectional meta-analysis of 87 observational studies
- 2018
-
In: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165. ; 108:3, s. 453-475
-
Journal article (peer-reviewed)abstract
- Background: Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes. Objective: A collaborative cross-sectionalmeta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span. Design: Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Studyspecific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity. Results: Each unit increase in BMI corresponded to a-3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI:-10.03,-5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10-3 unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10-3, -1.01 × 10-3) difference in ageand sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10-3 unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10-3, -1.25 × 10-3). The associations were predominantly for the white pooled population. No sex differences were observed. Conclusions: A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL arewarranted.
|
|
| 12. |
- González-Gil, Esther María, et al.
(author)
-
Prospective associations between dietary patterns and high sensitivity C-reactive protein in European children: the IDEFICS study.
- 2018
-
In: European journal of nutrition. - : Springer Science and Business Media LLC. - 1436-6215 .- 1436-6207. ; 57:4, s. 1397-1407
-
Journal article (peer-reviewed)abstract
- This prospective study explores high sensitivity C-reactive protein (hs-CRP) levels in relation to dietary patterns at two time points in European children.Out of the baseline sample of the IDEFICS study (n=16,228), 4020 children, aged 2-9 years at baseline, with available hs-CRP levels and valid data from a food frequency questionnaire (FFQ) at baseline (T0) and 2 years later (T1) were included. K-means clustering algorithm based on the similarities between relative food consumption frequencies of the FFQ was applied. hs-CRP was dichotomized according to sex-specific cutoff points. Multilevel logistic regression was performed to assess the relationship between dietary patterns and hs-CRP adjusting for covariates.Three consistent dietary patterns were found at T0 and T1: 'animal protein and refined carbohydrate', 'sweet and processed' and 'healthy'. Children allocated to the 'protein' and 'sweet and processed' clusters at both time points had significantly higher odds of being in the highest category of hs-CRP (OR 1.47; 95% CI 1.03-2.09 for 'animal protein and refined carbohydrate' and OR 1.44; 95% CI 1.08-1.92 for 'sweet and processed') compared to the 'healthy' cluster. The odds remained significantly higher for the 'sweet and processed' pattern (OR 1.39; 95% CI 1.05-1.84) when covariates were included.A dietary pattern characterized by frequent consumption of sugar and processed products and infrequent consumption of vegetables and fruits over time was independently related with inflammation in European children. Efforts to improve the quality of the diet in childhood may prevent future diseases related with chronic inflammation.
|
|
| 13. |
- Horikoshi, Momoko, et al.
(author)
-
Discovery and Fine-Mapping of Glycaemic and Obesity-Related Trait Loci Using High-Density Imputation.
- 2015
-
In: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7404 .- 1553-7390. ; 11:7
-
Journal article (peer-reviewed)abstract
- Reference panels from the 1000 Genomes (1000G) Project Consortium provide near complete coverage of common and low-frequency genetic variation with minor allele frequency ≥0.5% across European ancestry populations. Within the European Network for Genetic and Genomic Epidemiology (ENGAGE) Consortium, we have undertaken the first large-scale meta-analysis of genome-wide association studies (GWAS), supplemented by 1000G imputation, for four quantitative glycaemic and obesity-related traits, in up to 87,048 individuals of European ancestry. We identified two loci for body mass index (BMI) at genome-wide significance, and two for fasting glucose (FG), none of which has been previously reported in larger meta-analysis efforts to combine GWAS of European ancestry. Through conditional analysis, we also detected multiple distinct signals of association mapping to established loci for waist-hip ratio adjusted for BMI (RSPO3) and FG (GCK and G6PC2). The index variant for one association signal at the G6PC2 locus is a low-frequency coding allele, H177Y, which has recently been demonstrated to have a functional role in glucose regulation. Fine-mapping analyses revealed that the non-coding variants most likely to drive association signals at established and novel loci were enriched for overlap with enhancer elements, which for FG mapped to promoter and transcription factor binding sites in pancreatic islets, in particular. Our study demonstrates that 1000G imputation and genetic fine-mapping of common and low-frequency variant association signals at GWAS loci, integrated with genomic annotation in relevant tissues, can provide insight into the functional and regulatory mechanisms through which their effects on glycaemic and obesity-related traits are mediated.
|
|
| 14. |
- Hägg, Sara, et al.
(author)
-
Adiposity as a cause of cardiovascular disease : a Mendelian randomization study
- 2015
-
In: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 44:2, s. 578-586
-
Journal article (peer-reviewed)abstract
- Background: Adiposity, as indicated by body mass index (BMI), has been associated with risk of cardiovascular diseases in epidemiological studies. We aimed to investigate if these associations are causal, using Mendelian randomization (MR) methods. Methods: The associations of BMI with cardiovascular outcomes [coronary heart disease (CHD), heart failure and ischaemic stroke], and associations of a genetic score (32 BMI single nucleotide polymorphisms) with BMI and cardiovascular outcomes were examined in up to 22 193 individuals with 3062 incident cardiovascular events from nine prospective follow-up studies within the ENGAGE consortium. We used random-effects meta-analysis in an MR framework to provide causal estimates of the effect of adiposity on cardiovascular outcomes. Results: There was a strong association between BMI and incident CHD (HR = 1.20 per SD-increase of BMI, 95% CI, 1.12-1.28, P = 1.9.10(-7)), heart failure (HR = 1.47, 95% CI, 1.35-1.60, P = 9.10(-19)) and ischaemic stroke (HR = 1.15, 95% CI, 1.06-1.24, P = 0.0008) in observational analyses. The genetic score was robustly associated with BMI (beta = 0.030 SD-increase of BMI per additional allele, 95% CI, 0.028-0.033, P = 3.10(-107)). Analyses indicated a causal effect of adiposity on development of heart failure (HR = 1.93 per SD-increase of BMI, 95% CI, 1.12-3.30, P = 0.017) and ischaemic stroke (HR = 1.83, 95% CI, 1.05-3.20, P = 0.034). Additional cross-sectional analyses using both ENGAGE and CARDIoGRAMplusC4D data showed a causal effect of adiposity on CHD. Conclusions: Using MR methods, we provide support for the hypothesis that adiposity causes CHD, heart failure and, previously not demonstrated, ischaemic stroke.
|
|
| 15. |
- Jackson, Victoria E, et al.
(author)
-
Meta-analysis of exome array data identifies six novel genetic loci for lung function.
- 2018
-
In: Wellcome open research. - : F1000 Research Ltd. - 2398-502X. ; 3
-
Journal article (peer-reviewed)abstract
- Background: Over 90 regions of the genome have been associated with lung function to date, many of which have also been implicated in chronic obstructive pulmonary disease. Methods: We carried out meta-analyses of exome array data and three lung function measures: forced expiratory volume in one second (FEV 1), forced vital capacity (FVC) and the ratio of FEV 1 to FVC (FEV 1/FVC). These analyses by the SpiroMeta and CHARGE consortia included 60,749 individuals of European ancestry from 23 studies, and 7,721 individuals of African Ancestry from 5 studies in the discovery stage, with follow-up in up to 111,556 independent individuals. Results: We identified significant (P<2·8x10 -7) associations with six SNPs: a nonsynonymous variant in RPAP1, which is predicted to be damaging, three intronic SNPs ( SEC24C, CASC17 and UQCC1) and two intergenic SNPs near to LY86 and FGF10. Expression quantitative trait loci analyses found evidence for regulation of gene expression at three signals and implicated several genes, including TYRO3 and PLAU. Conclusions: Further interrogation of these loci could provide greater understanding of the determinants of lung function and pulmonary disease.
|
|
| 16. |
- Jelenkovic, Aline, et al.
(author)
-
Associations between birth size and later height from infancy through adulthood : An individual based pooled analysis of 28 twin cohorts participating in the CODATwins project
- 2018
-
In: Early Human Development. - : Elsevier BV. - 0378-3782 .- 1872-6232. ; 120, s. 53-60
-
Journal article (peer-reviewed)abstract
- Background: There is evidence that birth size is positively associated with height in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. Aim: To analyze the associations of birth weight, length and ponderal index with height from infancy through adulthood within mono- and dizygotic twin pairs, which provides insights into the role of genetic and environmental individual-specific factors. Methods: This study is based on the data from 28 twin cohorts in 17 countries. The pooled data included 41,852 complete twin pairs (55% monozygotic and 45% same-sex dizygotic) with information on birth weight and a total of 112,409 paired height measurements at ages ranging from 1 to 69 years. Birth length was available for 19,881 complete twin pairs, with a total of 72,692 paired height measurements. The association between birth size and later height was analyzed at both the individual and within-pair level by linear regression analyses. Results: Within twin pairs, regression coefficients showed that a 1-kg increase in birth weight and a 1-cm increase in birth length were associated with 1.14–4.25 cm and 0.18–0.90 cm taller height, respectively. The magnitude of the associations was generally greater within dizygotic than within monozygotic twin pairs, and this difference between zygosities was more pronounced for birth length. Conclusion: Both genetic and individual-specific environmental factors play a role in the association between birth size and later height from infancy to adulthood, with a larger role for genetics in the association with birth length than with birth weight.
|
|
| 17. |
- Jelenkovic, Aline, et al.
(author)
-
Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age : A Study of the CODATwins Project
- 2015
-
In: Twin Research and Human Genetics. - : Cambridge University Press. - 1832-4274 .- 1839-2628. ; 18:5, s. 557-570
-
Journal article (peer-reviewed)abstract
- A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m(2) in childhood and adolescence and up to 0.2 kg/m(2) in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
|
|
| 18. |
- Johansson Capusan, Andrea, 1970-
(author)
-
Environmental and Genetic Influences in Attention Deficit Hyperactivity Disorder (ADHD) and its Comorbidities
- 2016
-
Doctoral thesis (other academic/artistic)abstract
- Research in past decades has demonstrated the persistence of attention deficit hyperactivity disorder (ADHD) into adulthood, but many questions regarding prevalence, causes, and comorbidities of ADHD in adults remain to be investigated. Previous research focusing on childhood ADHD identified high heritability. Genetic and environmental influences on ADHD symptoms in adults and their association with comorbid conditions are not fully understood.The overall aim of this thesis was to study adult ADHD symptoms in the population and investigate associations with substance use disorders (SUD) and binge eating. In all four papers, we used population-based self-report data from twins aged 20–46 years from the Swedish Twin Registry. We used twin methods to explore the role of genetic and environmental factors underlying ADHD symptoms and their comorbidities.Study I examined the phenotypic association between ADHD and various forms of SUD. ADHD in adults was strongly associated with alcohol abuse and alcohol dependence, illicit drug use and regular nicotine use, with no differences between ADHD subtypes and no apparent substance preference. In Studies II and IV, we used bivariate twin models to examine the role of genetic and environmental factors in the association of adult ADHD symptoms with alcohol dependence (II) and with binge eating (IV). For ADHD symptoms and alcohol dependence, 64% of the overlap was explained by common genetic factors. The remaining variance was accounted for by environmental factors specific for each twin, with no sex differences for the overlap. Similarly, 91% of the association between ADHD symptoms and binge-eating behaviour was explained by common genetic factors. In Study III, using a within-twin pair analysis, we demonstrated that although most of the association between adult ADHD symptoms and self-reported childhood maltreatment (an environmental risk factor for ADHD) was explained by familial (genetic and environmental) confounding, our results were also consistent with a causal interpretation.In conclusion, adult ADHD symptoms are associated with SUD and binge-eating behaviour. We replicated findings from adolescent studies regarding shared genetic risk factors for alcohol dependence and ADHD symptoms in adults. For binge eating, we showed for the first time that shared genetic factors mainly explained the association with ADHD symptoms. Alterations in mesolimbic reward processing as well as the frontal, executive and inhibitory systems have been described for ADHD, alcohol dependence and binge-eating behaviour, possibly suggesting common genetic and neurobiological factors for all three conditions. Results that support a causal hypothesis regarding the association between childhood maltreatment and ADHD symptoms in adults need follow-up in longitudinal clinical samples that can examine neurobiological underpinnings of environmental effects. Clinically, the results of this thesis support that ADHD in adults be considered and addressed in adults with SUD or binge-eating behaviour. Given the common genetic risk factors and the role of the early childhood environment, family interventions should be considered for these populations.
|
|
| 19. |
- Kivimäki, Mika, et al.
(author)
-
Body mass index and risk of dementia : Analysis of individual-level data from 1.3 million individuals
- 2018
-
In: Alzheimer's & Dementia. - : Elsevier. - 1552-5260 .- 1552-5279. ; 14:5, s. 601-609
-
Journal article (peer-reviewed)abstract
- Introduction: Higher midlife body mass index (BMI) is suggested to increase the risk of dementia, but weight loss during the preclinical dementia phase may mask such effects. Methods: We examined this hypothesis in 1,349,857 dementia-free participants from 39 cohort studies. BMI was assessed at baseline. Dementia was ascertained at follow-up using linkage to electronic health records (N = 6894). We assumed BMI is little affected by preclinical dementia when assessed decades before dementia onset and much affected when assessed nearer diagnosis. Results: Hazard ratios per 5-kg/m(2) increase in BMI for dementia were 0.71 (95% confidence interval = 0.66-0.77), 0.94 (0.89-0.99), and 1.16 (1.05-1.27) when BMI was assessed 10 years, 10-20 years, and >20 years before dementia diagnosis. Conclusions: The association between BMI and dementia is likely to be attributable to two different processes: a harmful effect of higher BMI, which is observable in long follow-up, and a reverse-causation effect that makes a higher BMI to appear protective when the follow-up is short. (C) 2017 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer's Association.
|
|
| 20. |
- Konki, Mikko, et al.
(author)
-
Peripheral blood DNA methylation differences in twin pairs discordant for Alzheimer's disease.
- 2019
-
In: Clinical Epigenetics. - : BioMed Central. - 1868-7083 .- 1868-7075. ; 11:1
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Alzheimer's disease results from a neurodegenerative process that starts well before the diagnosis can be made. New prognostic or diagnostic markers enabling early intervention into the disease process would be highly valuable. Environmental and lifestyle factors largely modulate the disease risk and may influence the pathogenesis through epigenetic mechanisms, such as DNA methylation. As environmental and lifestyle factors may affect multiple tissues of the body, we hypothesized that the disease-associated DNA methylation signatures are detectable in the peripheral blood of discordant twin pairs.RESULTS: Comparison of 23 disease discordant Finnish twin pairs with reduced representation bisulfite sequencing revealed peripheral blood DNA methylation differences in 11 genomic regions with at least 15.0% median methylation difference and FDR adjusted p value ≤ 0.05. Several of the affected genes are primarily associated with neuronal functions and pathologies and do not display disease-associated differences in gene expression in blood. The DNA methylation mark in ADARB2 gene was found to be differentially methylated also in the anterior hippocampus, including entorhinal cortex, of non-twin cases and controls. Targeted bisulfite pyrosequencing of the DNA methylation mark in ADARB2 gene in 62 Finnish and Swedish twin pairs revealed that, in addition to the disease status, DNA methylation of this region is influenced by gender, age, zygosity, APOE genotype, and smoking. Further analysis of 120 Swedish twin pairs indicated that this specific DNA methylation mark is not predictive for Alzheimer's disease and becomes differentially methylated after disease onset.CONCLUSIONS: DNA methylation differences can be detected in the peripheral blood of twin pairs discordant for Alzheimer's disease. These DNA methylation signatures may have value as disease markers and provide insights into the molecular mechanisms of pathogenesis. We found no evidence that the DNA methylation marks would be associated with gene expression in blood. Further studies are needed to elucidate the potential importance of the associated genes in neuronal functions and to validate the prognostic or diagnostic value of the individual marks or marker panels.
|
|
