scholarly journals Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts

2017 ◽  
Vol 20 (5) ◽  
pp. 395-405 ◽  
Author(s):  
Karri Silventoinen ◽  
Aline Jelenkovic ◽  
Antti Latvala ◽  
Reijo Sund ◽  
Yoshie Yokoyama ◽  
...  
Keyword(s):  
Parental Education ◽  
Twin Studies ◽  
Pooled Analysis ◽  
Linear Regression Models ◽  
Birth Cohorts ◽  
Individual Level ◽  
Paternal Education ◽  
Males And Females ◽  
Adult Twins ◽  
Mz Twins

Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

scholarly journals The Personalities of Twins: Just Ordinary Folks

Twin Research ◽  
2002 ◽  
Vol 5 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Wendy Johnson ◽  
Robert F. Krueger ◽  
Thomas J. Bouchard ◽  
Matt McGue
Keyword(s):  
Twin Studies ◽  
Psychological Research ◽  
Effect Sizes ◽  
Large Samples ◽  
Social Closeness ◽  
Twin Registry ◽  
Three Samples ◽  
Males And Females ◽  
Mean Differences ◽  
Mz Twins

AbstractTwin studies have demonstrated that personality traits show moderate genetic influence. The conclusions drawn from twin studies rely on the assumptions that twins are representative of the population at large and that monozygotic and dizygotic twins are comparable in every way that might have bearing on the traits being studied. To evaluate these assumptions, we used Multidimensional Personality Questionnaire (MPQ) data from three samples drawn from the Minnesota Twin Registry (totaling 12,971 respondents) to examine the effect sizes associated with mean differences on the 11 MPQ scales and 3 higher-order MPQ factors for singletons versus twins and MZ twins versus DZ twins. The singletons in the samples were family members of the participating twins. We also used ratios of scale variances to examine the significance of variance differences. The only mean or variance difference replicated across all three samples was greater Social Closeness (about .1 standard deviation) for twins than for singletons. This difference was obtained for both males and females. It would appear that, with respect to personality, twins are not systematically different from other people. Our results also highlight the importance of replication in psychological research because each of our large samples showed differences not replicated in other samples.

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.

scholarly journals Iatrogenic Influences on the Heritability of Childhood Tonsillectomy: Cohort Differences in Twin Concordance

1991 ◽  
Vol 40 (2) ◽  
pp. 165-172 ◽  
Author(s):  
N.G. Martin ◽  
U. Kehren ◽  
D. Battistutta ◽  
J.D. Mathews
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Equal Size ◽  
Shared Environment ◽  
Birth Cohorts ◽  
Cohort Differences ◽  
The 1950S ◽  
Adult Twins ◽  
Mz Twins

AbstractIn 1980-82, a mailed questionnaire was completed by 3,810 pairs of adult twins enrolled on the Australian NH&MRC Twin Register. Twins were asked whether they had had their tonsils out and, if so, at what age. The sample was divided into four birth cohorts of approximately equal size, and only childhood tonsillectomy (to the age of 18) was considered. The prevalence of tonsillectomy differed markedly between cohorts, being highest in those born in the 1940s and early 1950s. Within each cohort, the prevalence was very similar in MZ and DZ twins, yet concordance was much higher in MZ twins, indicating the importance of genetic factors in predisposition to tonsillectomy. However, the proportions of variance in liability due to genetic and shared environmental factors differed markedly between cohorts. In the 1950s, when tonsillectomy was fashionable, shared environment accounted for 60% of variance and genetic factors for only 29%. However, by the early 1960s, when tonsillectomy was going out of fashion, heritability was up to 0.82 and shared environment accounted for only 10% of variance. Our results illustrate, once again, that heritability is not a constant, but depends on the precise characteristics of the population and the time at which it is studied.

scholarly journals The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits

2015 ◽  
Vol 18 (4) ◽  
pp. 348-360 ◽  
Author(s):  
Karri Silventoinen ◽  
Aline Jelenkovic ◽  
Reijo Sund ◽  
Chika Honda ◽  
Sari Aaltonen ◽  
...  
Keyword(s):  
Large Scale ◽  
Genetic Research ◽  
Twin Studies ◽  
Repeated Measurements ◽  
Human Populations ◽  
Birth Cohorts ◽  
Related Factors ◽  
Individual Level ◽  
Heritability Estimates ◽  
New Research

For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.

Archival Big Data and the Spanish Flu in Copenhagen

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kim Abildgren
Keyword(s):  
Big Data ◽  
Birth Cohort ◽  
Mortality Risk ◽  
Early Life ◽  
Birth Cohorts ◽  
Content Type ◽  
Individual Level ◽  
Early Life Exposure ◽  
Spanish Flu ◽  
One Year

Purpose The Spanish Flu 1918–1920 saw a high degree of excess mortality among young and healthy adults. The purpose of this paper is a further exploration of the hypothesis that high mortality risk during The Spanish Flu in Copenhagen was associated with early life exposure to The Russian Flu 1889–1892. Design/methodology/approach Based on 37,000 individual-level death records in a new unique database from The Copenhagen City Archives combined with approximate cohort-specific population totals interpolated from official censuses of population, the author compiles monthly time series on all-cause mortality rates 1916–1922 in Copenhagen by gender and one-year birth cohorts. The author then analyses birth cohort effects on mortality risk during The Spanish Flu using regression analysis. Findings The author finds support for hypotheses relating early life exposure to The Russian Flu to mortality risk during The Spanish Flu. Some indications of possible gender heterogeneity during the first wave of The Spanish Flu – not found in previous studies – should be a topic for future research based on data from other countries. Originality/value Due to lack of individual-level death records with exact dates of birth and death, previous studies on The Spanish Flu in Denmark and many other countries have relied on data with lower birth cohort resolutions than the one-year birth cohorts used in this study. The analysis in this paper illustrates how archival Big Data can be used to gain new insights in studies on historical pandemics.

Abstract P255: Association of Mild Chronic Kidney Disease with Venous Thromboembolism: Pooled Analysis of Prospective General Population Cohorts

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Bakhtawar K Mahmoodi ◽  
Ron T Gansevoort ◽  
Inger Anne Naess ◽  
Pamela L Lutsey ◽  
Sigrid K Braekkan ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Venous Thromboembolism ◽  
Kidney Disease ◽  
General Population ◽  
Cox Regression ◽  
Meta Analysis ◽  
Random Effect ◽  
Pooled Analysis ◽  
Individual Level ◽  
Increased Risk

Background: Recent findings suggest that mild chronic kidney disease (CKD) might be associated with increased risk of venous thromboembolism (VTE). However, results were partially inconsistent, which may be due to lack of power. We therefore performed a meta-analysis to investigate the association between mild CKD and VTE incidence. Methods: A literature search was performed to retrieve community-based cohorts with information on the association of estimated glomerular filtration rate (eGFR) and albuminuria with VTE. Five cohorts were identified that were pooled on individual level. To obtain pooled hazard ratios (HRs) for VTE, linear spline models were fitted using Cox regression with shared-frailty. Models were adjusted for age, sex, hypertension, total cholesterol, smoking, diabetes, history of cardiovascular disease and body-mass index. Random-effect meta-analysis was used to obtain adjusted pooled HRs of VTE with CKD versus no CKD. Results: The analysis included 95,154 participants with 1,178 VTE cases and 599,453 person-years of follow-up. Risk of VTE increased continuously with lower eGFR and higher ACR (Figure). Compared with eGFR 100 mL/min/1.73m², pooled adjusted HRs for VTE were 1.3 (1.0–1.7) for eGFR 60, 1.8 (1.3–2.6) for 45 and 1.9 (1.2–2.9) for 30 mL/min/1.73m². Compared with albumin-creatinine ratio (ACR) 5 mg/g, pooled adjusted HRs for VTE were 1.3 (1.04–1.7) for ACR 30, 1.6 (1.1–2.4) for 300 and 1.9 (1.2–3.1) for 1000 mg/g. There was no evidence for interaction between eGFR and ACR (P=0.22). The pooled adjusted HR for CKD (eGFR <60 ml/min/1.73m² or albuminuria ≥30 mg/g) vs. no CKD was 1.5 (95%CI, 1.2–2.1). Results were similar for idiopathic and provoked VTE. Conclusion: Both reduced eGFR and elevated albuminuria are novel independent predictors of VTE in the general population.

scholarly journals The incidence of left-handedness: a meta-analysis [1993]

2019 ◽  
Author(s):  
Ian Christopher McManus
Keyword(s):  
Sex Difference ◽  
Meta Analysis ◽  
Birth Cohorts ◽  
Future Studies ◽  
Left Handedness ◽  
Left Handed ◽  
Method Of Measurement ◽  
Males And Females ◽  
Older Subjects ◽  
Unpublished Manuscripts

A meta-analysis is reported of 88 studies, examining 100 study populations, in which the handedness of 284665 individuals has been assessed. The overall incidence of left-handedness was 7.78%. The incidence of left-handedness was not related to the method of measurement, or the length or number of response items included in inventories. Study populations with lower response rates and smaller study populations showed some evidence of higher incidences of left-handedness, presumably due to response biasses. There was no evidence that the incidence of left-handedness was related to the year of publication of studies; however the incidence of left-handedness was lower in older subjects and in those from earlier birth cohorts, the two effects not being statistically distinguishable.Information was available from 64 study populations concerning the incidence of left-handedness in males and females; overall 8.52% of males were left-handed compared with 6.69% of females, the male incidence being 27.4% higher than that in females. Although there was some suggestion that the sex difference was greater in larger studies, and in studies whose main purpose was not the study of handedness, these differences were not significant. It is concluded that the size of the sex difference is unrelated to any of the moderator variables we have studied.It was not possible to carry out a meta-analysis of degree of handedness due to wide-spread differences in the method of reporting of degree of handedness.We recommend that future studies of handedness should, as a minimum, use one of three standard methods of assessment, so that comparison of studies is facilitated. Note: This manuscript was originally prepared in 1993 but due to problems at a major journal, described briefly, was never eventually published. It has however been cited on a number of occasions, and has been available at https://www.ucl.ac.uk/medical-education/publications/unpublished-manuscripts/meta-analysis-of-handedness . A major meta-analysis of handedness in 2019 by another author has now been submitted which cites this manuscript, and therefore it needs to be available in a more archivable format.

scholarly journals The Gender Outcomes International Group: to Further Well-being Development (Going-fwd) Methodology on Identification and Inclusion of Gender Factors in Retrospective Cohort Studies

2020 ◽  
Author(s):  
Valeria Raparelli Raparelli ◽  
Colleen M. Norris ◽  
Uri Bender ◽  
Maria Trinidad Herrero ◽  
Alexandra Kautzky-Willer ◽  
...  
Keyword(s):  
Data Structure ◽  
Meta Analysis ◽  
Synthetic Data ◽  
Well Being ◽  
Pooled Analysis ◽  
Research Network ◽  
Local Analysis ◽  
Related Factors ◽  
Individual Level ◽  
Definition Of

Abstract Background: Gender refers to the socially constructed roles, behaviors, expressions, and identities of girls, women, boys, men, and gender diverse people. It influences self-perception, individual’s actions and interactions, as well as the distribution of power and resources in society. Gender-related factors are seldom assessed as determinants of health outcomes, despite their powerful contribution.Methods: Investigators of the GOING-FWD project developed a standard methodology applicable for observational studies to retrospectively identify gender-related factors to assess their relationship to outcomes and applied this method to selected cohorts of non-communicable chronic diseases from Austria, Canada, Spain, Sweden.Results: The following multistep process was applied. Step 1 (Identification of Gender-related Variables): Based on the gender framework of the Women Health Research Network (i.e. gender identity, role, relations, and institutionalized gender), and available literature for a certain disease, an optimal “wish-list” of gender-related variables/factors was created and discussed by experts. Step 2 (Definition of Outcomes): each of the cohort data dictionaries were screened for clinical and patient relevant outcomes, using the ICHOM framework. Step 3 (Building of Feasible Final List): A cross-validation between gender-related and outcome variables available per database and the “wish-list” was performed. Step 4 (Retrospective Data Harmonization): The harmonization potential of variables was evaluated. Step 5 (Definition of Data Structure and Analysis): Depending on the database data structure, the following analytic strategies were identified: (1) local analysis of data not transferable followed by a meta-analysis combining study-level estimates; (2) centrally performed federated analysis of anonymized data, with the individual-level participant data remaining on local servers; (3) synthesizing the data locally and performing a pooled analysis on the synthetic data; and (4) central analysis of pooled transferable data.Conclusion: The application of the GOING-FWD systematic multistep approach can help guide investigators to analyze gender and its impact on outcomes in previously collected data.

scholarly journals WHETHER INDIVIDUALISM MAKES PEOPLE FROM THE “WEST” HAPPIER AND COLLECTIVISM MAKES PEOPLE FROM THE “EAST” MORE SATISFIED IN LIFE: AN INDIVIDUAL-LEVEL ANALYSIS

2019 ◽  
Vol 128 (6B) ◽  
pp. 57
Author(s):  
Nguyễn Hữu An ◽  
Lê Duy Mai Phương
Keyword(s):  
Interpersonal Relationships ◽  
Well Being ◽  
Cultural Dimension ◽  
Subjective Well Being ◽  
Linear Regression Models ◽  
The West ◽  
Individual Level ◽  
Collectivistic Cultures ◽  
The Individual ◽  
Level Of Analysis

Determinants of the variation of happiness have long been discussed in social sciences. Recent studies have focused on investigating cultural factors contributing to the level of individual happiness, in which the cultural dimension of individualism (IND) and collectivism (COL) has been drawing the attention of a large number of scholars. At the cultural level of analysis, happiness is associated with personal achievements as well as personal egoism in individualistic cultures, while it is related to interpersonal relationships in collectivistic cultures. Empirical research yields unconventional results at the individual level of analysis, that is, individuals in collectivistic cultures favor IND to be happy, in contrast, people in individualistic cultures emphasize COL be satisfied in life. Using data from the fifth wave of the World Values Survey (WVS), this study takes the cultural dimension of IND and COL at the individual level of analysis to detect its effects on happiness (conceptualized as subjective well-being – SWB) in the comparison between the two cultures. Multiple linear regression models reveal results that individuals from the “West” experience greater happiness when they expose themselves less individualist, while, individuals from the “East” feel more satisfied and happier in their life when they emphasize more on IND or being more autonomous.

scholarly journals Sex Differences in Spironolactone and the Active Metabolite Canrenone Concentrations and Adherence

Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 137
Author(s):  
Laura E. J. Peeters ◽  
Leonardien K. Tjong ◽  
Wim J. R. Rietdijk ◽  
Teun van Gelder ◽  
Birgit C. P. Koch ◽  
...  
Keyword(s):  
Sex Differences ◽  
Resistant Hypertension ◽  
Active Metabolite ◽  
Drug Exposure ◽  
Antihypertensive Drugs ◽  
Controlled Trial ◽  
Linear Regression Models ◽  
Blood Concentrations ◽  
Males And Females ◽  
Post Hoc

We aim to investigate sex differences in blood concentrations of spironolactone and the active metabolite canrenone in resistant hypertension patients. Furthermore, sex differences in adherence for spironolactone and other antihypertensive drugs (AHDs) were studied. The patients in this post hoc study had all participated in a single-blind randomized controlled trial called RHYME-RCT (Dutch Trial Register, NL6736). Concentrations in blood of several AHDs were assessed in RHYME-RCT to investigate adherence to treatment. This allowed for a comparison of drug exposure to spironolactone and canrenone between males and females. In linear regression models, no statistically significant sex differences (N = 35) in spironolactone (B =−10.23, SE = 7.92, p = 0.206) or canrenone (B = 1.24, SE = 10.96, p = 0.911) concentrations after adjustment for dose and time between sampling and intake were found. Furthermore, no statistically significant differences in non-adherence to spironolactone were found between sexes (N = 54, male 15% vs. female 38%, p = 0.100), but non-adherence to spironolactone was associated with non-adherence to other AHDs (p ≤ 0.001). Spironolactone and canrenone concentrations were not different between males and females with resistant hypertension. Although not statistically significant, females were twice as likely to be non-adherent to spironolactone compared to males, and thereby also more likely to be non-adherent to other AHDs.

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