No Evidence of Genetic Mediation in the Association Between Birthweight and Academic Performance in 2,413 Danish Adolescent Twin Pairs

2009 ◽  
Vol 12 (6) ◽  
pp. 564-572 ◽  
Author(s):  
Inge Petersen ◽  
Vibeke Myrup Jensen ◽  
Matt McGue ◽  
Paul Bingley ◽  
Kaare Christensen
Keyword(s):  
Academic Performance ◽  
Genetic Factors ◽  
Large Population ◽  
Twin Studies ◽  
Positive Association ◽  
Population Based ◽  
Birth Cohorts ◽  
Individual Level ◽  
Shed Light ◽  
Danish Twin

AbstractEvidence of a positive association between birthweight and IQ has been established in several studies. Analyses of within twin pair differences in birthweight and IQ have been used to shed light on the basis of the association. The strength of this approach is the possibility of controlling for both unmeasured common childhood–environmental factors as well as genetic factors shared by the co-twins. Two twin studies suggest the existence of genetic mediation between birthweight and IQ, that is, common genetic factors influence both fetal growth and IQ in childhood, while two other twin studies find no evidence of such mediation. In the present study we use a large population-based national register study of 2,413 Danish twin-pairs from birth cohorts 1986–1990, of which we have zygosity information on 74%. We perform individual level as well as intra-pair analyses of birthweight and school achievements at age 16. For both sexes we observed a monotonic increase in academic performance with increasing percentiles of birthweight. However, we did not find that this association is due to genetic mediation.

Genetic Factors Account for Half of the Phenotypic Variance in Liability to Sleep-Related Bruxism in Young Adults: A Nationwide Finnish Twin Cohort Study

2012 ◽  
Vol 15 (6) ◽  
pp. 714-719 ◽  
Author(s):  
Katariina Rintakoski ◽  
Christer Hublin ◽  
Frank Lobbezoo ◽  
Richard J. Rose ◽  
Jaakko Kaprio
Keyword(s):  
Cohort Study ◽  
Gender Difference ◽  
Genetic Factors ◽  
Genetic Model ◽  
Large Population ◽  
Population Based ◽  
Genetic Effects ◽  
Phenotypic Variance ◽  
Birth Cohorts ◽  
Additive Genetic Effects

Objectives: The aim of the present study was to examine the role of genetic and environmental factors in the phenotypic variance of bruxism in a large population-based cohort of young adult twins in Finland.Methods: The material of the present study derives from the FinnTwin16 cohort study consisting of five birth cohorts of twin pairs born in 1975–1979 who completed a questionnaire (at mean age 24, range 23–27 years) with data on frequency of sleep-related bruxism in 2000–2002. We used quantitative genetic modeling, based on the genetic similarity of monozygotic and dizygotic twins, to estimate the most probable genetic model for bruxism, based on decomposition of phenotypic variance into components: additive genetic effects (A), dominant genetic effects (D), and non-shared environmental effects (E).Results: On average, 8.7% experienced bruxism weekly, 23.4% rarely, and 67.9% never, with no significant gender difference (p = .052). The best fitting genetic model for bruxism was the AE-model. Additive genetic effects accounted for 52% (95% CI 0.41–0.62) of the total phenotypic variance. Sex-limitation model revealed no gender differences.Conclusions: Genetic factors account for a substantial proportion of the phenotypic variation of the liability to sleep-related bruxism, with no gender difference in its genetic architecture.

scholarly journals Adjuvant Hormonotherapy and Cardiovascular Risk in Post-Menopausal Women with Breast Cancer: A Large Population-Based Cohort Study

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2254
Author(s):  
Matteo Franchi ◽  
Roberta Tritto ◽  
Luigi Tarantini ◽  
Alessandro Navazio ◽  
Giovanni Corrao
Keyword(s):  
Breast Cancer ◽  
Heart Failure ◽  
Adjuvant Therapy ◽  
Large Population ◽  
Positive Association ◽  
Population Based ◽  
Study Cohort ◽  
Increased Risk ◽  
Post Menopausal ◽  
New Diagnosis

Background: Whether aromatase inhibitors (AIs) increase the risk of cardiovascular (CV) events, compared to tamoxifen, in women with breast cancer is still debated. We evaluated the association between AI and CV outcomes in a large population-based cohort of breast cancer women. Methods: By using healthcare utilization databases of Lombardy (Italy), we identified women ≥50 years, with new diagnosis of breast cancer between 2009 and 2015, who started adjuvant therapy with either AI or tamoxifen. We estimated the association between exposure to AI and CV outcomes (including myocardial infarction, ischemic stroke, heart failure or any CV event) by a Cox proportional hazard model with inverse probability of treatment and censoring weighting. Results: The study cohort included 26,009 women starting treatment with AI and 7937 with tamoxifen. Over a median follow-up of 5.8 years, a positive association was found between AI and heart failure (Hazard Ratio = 1.20, 95% CI: 1.02 to 1.42) and any CV event (1.14, 1.00 to 1.29). The CV risk increased in women with previous CV risk factors, including hypertension, diabetes and dyslipidemia. Conclusions: Adjuvant therapy with AI in breast cancer women aged more than 50 years is associated with increased risk of heart failure and combined CV events.

Twin—Singleton Differences in Intelligence: A Meta-Analysis

2008 ◽  
Vol 102 (3) ◽  
pp. 951-962 ◽  
Author(s):  
Martin Voracek ◽  
Tanja Haubner
Keyword(s):  
Meta Analysis ◽  
Twin Studies ◽  
Developed Countries ◽  
Population Based ◽  
Insufficient Data ◽  
Birth Cohorts ◽  
Perinatal Factors ◽  
Study Heterogeneity ◽  
Fail Safe ◽  
Age Range

Since the emergence of twin studies in the 1920s, time and again the question of possible twin-singleton differences in intelligence has been posed. This study addressed the issue through a meta-analysis of published studies on this theme. Twins on the average seem to have lower IQs than singletons. The best estimate for this group difference is 4.2 IQ points (less than one-third of a standard deviation), with a great divide between study outcomes of less vs more recent birth cohorts (5.1 vs 0.5 IQ points, respectively). The evidence is based on studies from six countries (including population-based ones of entire birth cohorts), a massive database (comparisons of more than 30,000 twins with nearly 1.6 million singletons), a variety of intelligence tests, and birth cohorts spanning most of the 20th century, but, for the most part, on an age range limited to children and adolescents. The effect shows considerable between-study heterogeneity but appears robust (fail-safe N calculations), not due to influential individual studies (sensitivity analysis) or publication bias, was present since the very first published studies (cumulative meta-analysis), and appears generalizable across sex, zygosity, and other intelligence domains beyond the verbal. There are insufficient data as to whether the effect persists over the lifespan, exists as well within families, or has ceased in recent birth cohorts of highly developed countries (Denmark and The Netherlands). Likely causes of the effect appear to be prenatal and perinatal factors (reduced fetal growth and shorter gestation for twins).

A twin study of genetic and environmental influences on tobacco initiation, regular tobacco use and nicotine dependence

2004 ◽  
Vol 34 (7) ◽  
pp. 1251-1261 ◽  
Author(s):  
HERMINE H. MAES ◽  
PATRICK F. SULLIVAN ◽  
CYNTHIA M. BULIK ◽  
MICHAEL C. NEALE ◽  
CAROL A. PRESCOTT ◽  
...  
Keyword(s):  
Nicotine Dependence ◽  
Tobacco Use ◽  
Structural Equation ◽  
Genetic Factors ◽  
Smoking Behavior ◽  
Twin Studies ◽  
Population Based ◽  
Equation Modeling ◽  
Opposite Sex ◽  
Tobacco Initiation

Background. Numerous twin studies have reported significant genetic contributions to the variability of tobacco initiation (TI), while fewer studies have shown similar results for the persistence of smoking behavior, or nicotine dependence (ND). As the development of ND requires regular tobacco use (RTU) which in turn requires TI, a conditional approach is necessary.Method. We used structural equation modeling of multi-step conditional processes to examine the relationship between genetic and environmental risk factors for TI, RTU and ND. The tobacco variables were assessed by personal interview in female, male and opposite-sex twin pairs from the population-based Virginia Twin Registry.Results. The results suggested that the liabilities to TI, RTU and ND were correlated. Over 80% of the variance in liability to TI and RTU were shared, and a smaller proportion was shared between RTU and ND. The heritabilities were estimated at 75%, 80% and 60% respectively for TI, RTU and ND. The variance specific to liability to RTU was entirely accounted for by additive genetic factors. Only a modest part of the heritability in liability of ND was due to genetic factors specific to ND. Shared environmental factors were not significant. No sex differences were found for the sources of variation or causal paths, but prevalences were significantly greater in males versus females.Conclusions. This study showed significant overlap in the contribution of genetic factors to individual differences in TI, RTU and ND. Furthermore, there was evidence for significant additional genetic factors specific to RTU and ND.

Sleep and academic performance in later adolescence: results from a large population-based study

2016 ◽  
Vol 25 (3) ◽  
pp. 318-324 ◽  
Author(s):  
Mari Hysing ◽  
Allison G. Harvey ◽  
Steven J. Linton ◽  
Kristin G. Askeland ◽  
Børge Sivertsen
Keyword(s):  
Academic Performance ◽  
Large Population ◽  
Population Based ◽  
Population Based Study

Individual-level and area-level socioeconomic inequalities in hearing impairment among Chinese adults: a population-based study

2020 ◽  
pp. jech-2019-213437 ◽  
Author(s):  
Yanan Luo ◽  
Jiamin Gao ◽  
Xiaoying Zheng
Keyword(s):  
Hearing Impairment ◽  
Large Population ◽  
Pure Tone Audiometry ◽  
Population Based ◽  
Socioeconomic Inequalities ◽  
Sample Survey ◽  
Cross Sectional ◽  
Individual Level ◽  
Income Per Capita ◽  
Per Capita

BackgroundIt is unclear whether individual-level and area-level socioeconomic status (SES) is associated with hearing impairment (HI). This study determines an association of individual SES, area SES and their interaction with HI among working-aged adults.MethodsData were obtained from the large, population-based sample of the Second China National Sample Survey on Disability, a cross-sectional study conducted in China. A total of 1 333 528 participants aged 25–59 years were included. HI was measured by pure-tone audiometry (PTA) and audiologists further ascertained for a final diagnosis. Individual SES was defined as a summed of z-scored of education level and household income per capita, and area SES was calculated as a summed of z-scored of county-level income per capita, high school rate, poverty rate and rate of upper-class occupation. Multilevel logistic regression was used.ResultsIndividual and area SES were associated with HI among Chinese working-aged adults. A 1-SD increase in individual SES was associated with decreased risk of HI (OR=0.3, 95% CI: 0.3 to 0.3). Area SES was positively related to HI (OR=1.2, 95%CI: 1.2 to 1.3). The cross-level interaction on individual and area SES was significantly associated with HI, indicating that among those who lived in higher SES areas, participants with lower SES had a greater likelihood to develop HI.ConclusionsSignificant individual and area socioeconomic inequalities were observed in HI among Chinese working-aged adults. Lower SES adults who resided in prosperous areas may face more deprivation on hearing health than those with higher SES.

scholarly journals The association of disproportionately enlarged subarachnoid space hydrocephalus with cognitive deficit in a general population: the Ohasama study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomofumi Nishikawa ◽  
Ichiro Akiguchi ◽  
Michihiro Satoh ◽  
Azusa Hara ◽  
Mikio Hirano ◽  
...  
Keyword(s):  
Subarachnoid Space ◽  
Cognitive Deficit ◽  
Large Population ◽  
Positive Association ◽  
Normal Pressure ◽  
Population Based ◽  
Logistic Regression Models ◽  
New Development ◽  
Evans Index ◽  
Magnetic Resonance Imaging Mri

AbstractDisproportionately enlarged subarachnoid space hydrocephalus (DESH) is the characteristic feature of idiopathic normal pressure hydrocephalus. We aimed to characterize the prevalence, development, and association of DESH to cognitive deficit in a large population. We reviewed the data of 1384 subjects eligible for the present study among 1590 participants who underwent magnetic resonance imaging (MRI) in the Ohasama Study, a population-based study in Ohasama, Japan. The participants with Mini-Mental State Examination (MMSE) score <  = 25 were assumed to have cognitive deficit and DESH was evaluated by reviewing the MRIs. We assessed the association between DESH, Evans index (EI), and cognitive deficit using multivariate logistic regression models adjusted for relevant confounders. Furthermore, we evaluated the new development of DESH and the deterioration of cognitive function in the participants with DESH. There were nine participants with DESH (0.65%), seven of whom showed cognitive deficit. DESH was significantly associated with cognitive deficit in multivariate regression analyses (odds ratio; 8.50 [95% confidence interval: 1.61–44.88]). In the 669 participants who underwent follow-up MRI, we found four participants newly presenting with DESH; the development of DESH was observed before/after the presence of EI > 0.3. We also found two participants with existing DESH showing no remarkable worsening in MMSE and EI. The present study demonstrated a positive association between the presence of DESH and cognitive deficit. DESH can develop independently of EI > 0.3, and ventricular enlargement in combination with DESH may be an important factor in the worsening of cognitive deficit.

scholarly journals Twin Studies of Atopic Dermatitis: Interpretations and Applications in the Filaggrin Era

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Camilla Elmose ◽  
Simon Francis Thomsen
Keyword(s):  
Genetic Factors ◽  
Clinical Manifestations ◽  
Twin Studies ◽  
Population Based ◽  
Future Research ◽  
Atopic Diseases ◽  
Environmental Correlations ◽  
Disease Trait ◽  
Overall Ratio ◽  
The Relationship

Aim. The aim of this study was to conduct a systematic review of population-based twin studies of (a) the concordance and heritability of AD and (b) the relationship between AD and asthma and, furthermore, to reinterpret findings from previous twin studies in the light of the emerging knowledge about filaggrin and its role in the atopic march and provide suggestions for future research in this area. Methods. We identified all twin studies (published after 1970) that have calculated the concordance rate and/or the heritability of AD, or the genetic and environmental correlations between AD and asthma. Results. Reported concordance rates for AD ranged, respectively. From 0.15 to 0.86 for MZ and from 0.05 to 0.41 for DZ twins, with an overall ratio of MZ : DZ twins of approximately three. The heritability of AD was estimated to be approximately 75%, and the association between AD and asthma was around 85% explained by genetic pleiotropy. Conclusions. Genetic factors account for most of the variability in AD susceptibility and for the association between AD and asthma. Controversy remains as to whether the atopic diseases are causally related or whether they are diverse clinical manifestations of a common, underlying (genetic) disease trait. Future twin studies may help solve this enigma.

Twin studies and the heritability of MS: a conclusion

2009 ◽  
Vol 15 (6) ◽  
pp. 661-667 ◽  
Author(s):  
CH Hawkes ◽  
AJ Macgregor
Keyword(s):  
Small Sample Size ◽  
Large Population ◽  
Twin Studies ◽  
Genetic Effect ◽  
Population Based ◽  
Small Sample ◽  
Genetic Contribution ◽  
Research Strategies ◽  
Control Approach ◽  
Genes And Environment

Objective The classical twin study has the potential to evaluate the relative contribution of genes and environment and guide further research strategies, provided the sampling and methods of analysis are correct. We wish to review all the more informative twin studies on multiple sclerosis (MS). Methods We examined six large population-based twin studies in MS and calculated indices of heritability (h2), which is the traditional method of assessing genetic contribution to disease and to allow comparison between studies. Results This index was found to vary widely from 0.25 to 0.76 with large confidence intervals that reflect small sample size and prevent robust interpretation. Conclusion Overall the studies support a genetic contribution to disease; however, the imprecision of the heritability estimates and potential biases that they contain mean that very little inference can be drawn its exact size. Given that the magnitude of genetic effect cannot be measured because of the relative infrequency of MS; the consequent difficulty in collecting an informative sample; and in many countries, the lack of a comprehensive twin register, we suggest that further twin prevalence surveys should not be undertaken. Twin studies could be used more effectively in other ways, such as the co-twin case–control approach.

scholarly journals Metabolomic Profiles of Plasma Retinol-Associated Dyslipidemia in Men and Women

2021 ◽  
Vol 8 ◽  
Author(s):  
Ninglin Wang ◽  
Yuan Ru ◽  
Zhiying Yang ◽  
Changxuan Sun ◽  
Shanshan Li ◽  
...  
Keyword(s):  
Steroid Hormone ◽  
Large Population ◽  
Logistic Models ◽  
Positive Association ◽  
Population Based ◽  
Alpha Linolenic Acid ◽  
Men And Women ◽  
Hormone Synthesis ◽  
Plasma Retinol ◽  
Pathway Analyses

Background and Aims: Studies of both animals and humans show that a high intake of vitamin A is associated with a lower risk of dyslipidemia. However, an association of plasma retinol levels with dyslipidemia is unclear. Therefore, the aim of this study is to investigate an association between plasma retinol and dyslipidemia and to identify related metabolites and pathways in the general population.Methods: We included 250 participants aged 20–80 years from the Wellness Living Laboratory (WELL) China cohort. Associations between plasma retinol levels and dyslipidemia were analyzed using adjusted logistic models. Related metabolites were identified using ANCOVA, adjusted for the false discovery rate (FDR) and used for pathway analyses. Because there are sex differences in plasma retinol levels, all analyses were conducted separately by sex.Results: Plasma retinol was significantly higher in men than in women. A positive association between plasma retinol and dyslipidemia was found in both sexes. In men, the 2nd and 3rd tertiles showed significantly higher proportions of dyslipidemia than the 1st tertile (1st tertile vs. 2nd tertile: p = 0.026; 1st tertile vs. 3rd tertile: p = 0.003). In women, the 3rd tertile showed a significantly higher proportion of dyslipidemia than the 1st and 2nd tertile (3rd tertile vs. 1st tertile: p = 0.002, 3rd tertile vs. 2nd tertile: p = 0.002). Overall, 75 and 30 metabolites were significantly associated with retinol levels in men and women, respectively. According to these metabolites, lipid metabolic pathways, including glycerophospholipid, arachidonic acid, linoleic acid, alpha-linolenic acid, and glycosylphosphatidylinositol (GPI), as well as steroid hormone biosynthesis pathways were found to overlap across the sexes. These pathways showed that elevated retinol levels might be associated with hormone metabolism and inflammation status.Conclusions: We found a positive association between plasma retinol levels and dyslipidemia. Related metabolomic profiles and interrupted pathways showed that such an increase might be associated with steroid hormone synthesis and inflammation. In addition, large, population-based longitudinal studies and intervention studies are needed to confirm the role of retinol in lipid metabolism and the prevention of cardiovascular disease (CVD).

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