The Heritability of Mortality Due to Heart Diseases: A Correlated Frailty Model Applied to Danish Twins

Twin Research ◽  
2001 ◽  
Vol 4 (4) ◽  
pp. 266-274 ◽  
Author(s):  
Andreas Wienke ◽  
Niels V. Holm ◽  
Axel Skytthe ◽  
Anatoli I. Yashin
Keyword(s):  
Environmental Factors ◽  
Parametric Analysis ◽  
Structural Equation ◽  
Heart Diseases ◽  
Frailty Model ◽  
Equation Model ◽  
Shared Environment ◽  
Males And Females ◽  
Genetic And Environmental Factors

AbstractData of the Danish Twin Registry on monozygotic and dizygotic twins are used to analyse genetic and environmental influences on susceptibility to heart diseases for males and females, respectively. The sample includes 7955 like-sexed twin pairs born between 1870 and 1930. Follow-up was from 1 January 1943 to 31 December 1993 which results in truncation (twin pairs were included in the study if both individuals were still alive at the beginning of the follow-up) and censoring (nearly 40% of the study population was still alive at the end of the follow-up). We use the correlated gamma-frailty model for the genetic analysis of frailty to account for this censoring and truncation. During the follow-up 9370 deaths occurred, 3393 deaths were due to heart diseases in general, including 2476 deaths due to coronary heart disease (CHD). Proportions of variance of frailty attributable to genetic and environmental factors were analyzed using the structural equation model approach. Different standard biometric models are fitted to the data to evaluate the magnitude and nature of genetic and environmental factors on mortality. Using the best fitting model heritability of frailty (liability to death) was found to be 0.55 (0.07) and 0.53 (0.11) with respect to heart diseases and CHD, respectively, for males and 0.52 (0.10) and 0.58 (0.14) for females in a parametric analysis. A semi-parametric analysis shows very similar results. These analyses may indicate the existence of a strong genetic influence on individual frailty associated with mortality caused by heart diseases and CHD in both, males and females. The nature of genetic influences on frailty with respect to heart diseases and CHD is probably additive. No evidence for dominance and shared environment was found.

The Heritability of CHD Mortality in Danish Twins After Controlling for Smoking and BMI

2005 ◽  
Vol 8 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Andreas Wienke ◽  
Anne M. Herskind ◽  
Kaare Christensen ◽  
Axel Skytthe ◽  
Anatoli I. Yashin
Keyword(s):  
Environmental Factors ◽  
Structural Equation ◽  
Equation Model ◽  
Mortality Data ◽  
Best Fitting ◽  
Genetic And Environmental Factors ◽  
Individual Frailty ◽  
Fitting Model ◽  
Model Approach

AbstractCause-specific mortality data on Danish monozygotic and dizygotic twins are used to analyze heritability estimates of susceptibility to coronary heart disease (CHD) after controlling for smoking and Body Mass Index (BMI). The sample includes 1209 like-sexed twin pairs born between 1890 and 1920, where both individuals were still alive in 1966. The participants completed a questionnaire in 1966 which included questions on smoking, height and weight. The analysis was conducted with both sexes pooled due to the relatively small number of twin pairs. Follow-up was conducted from January 1, 1966 to December 31, 1993. The correlated gammafrailty model with observed covariates was used for the genetic analysis of frailty to account for censoring and truncation in the lifetime data. During the follow-up, 1437 deaths occurred, including 435 deaths due to CHD. Proportions of variance of frailty attributable to genetic and environmental factors were analyzed using the structural equation model approach. Different standard biometric models are fitted to the data to evaluate the magnitude and nature of genetic and environmental factors on mortality. Using the best-fitting model without covariates, heritability of frailty to CHD was found to be 0.45 (0.11). This result changes only slightly to 0.55 (0.13) in a DE model after controlling for smoking and BMI. This analysis underlines the existence of a substantial genetic influence on individual frailty associated with mortality caused by CHD.

scholarly journals Genetic and Environmental Influences on Smoking Behavior across Adolescence and Young Adulthood in the Virginia Twin Study of Adolescent Behavioral Development and the Transitions to Substance Abuse Follow-Up

2015 ◽  
Vol 18 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Elizabeth K. Do ◽  
Elizabeth C. Prom-Wormley ◽  
Lindon J. Eaves ◽  
Judy L. Silberg ◽  
Donna R. Miles ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Young Adulthood ◽  
Twin Study ◽  
Smoking Behavior ◽  
Smoking Initiation ◽  
Study Results ◽  
Adolescence And Young Adulthood ◽  
Genetic And Environmental Factors ◽  
The Relationship

Little is known regarding the underlying relationship between smoking initiation and current quantity smoked during adolescence into young adulthood. It is possible that the influences of genetic and environmental factors on this relationship vary across sex and age. To investigate this further, the current study applied a common causal contingency model to data from a Virginia-based twin study to determine: (1) if the same genetic and environmental factors are contributing to smoking initiation and current quantity smoked; (2) whether the magnitude of genetic and environmental factor contributions are the same across adolescence and young adulthood; and (3) if qualitative and quantitative differences in the sources of variance between males and females exist. Study results found no qualitative or quantitative sex differences in the relationship between smoking initiation and current quantity smoked, though relative contributions of genetic and environmental factors changed across adolescence and young adulthood. More specifically, smoking initiation and current quantity smoked remain separate constructs until young adulthood, when liabilities are correlated. Smoking initiation is explained by genetic, shared, and unique environmental factors in early adolescence and by genetic and unique environmental factors in young adulthood; while current quantity smoked is explained by shared environmental and unique environmental factors until young adulthood, when genetic and unique environmental factors play a larger role.

scholarly journals Exploring the Drivers behind Self-Reported and Measured Food Wastage

2019 ◽  
Vol 11 (20) ◽  
pp. 5677 ◽  
Author(s):  
Elimelech ◽  
Ert ◽  
Ayalon
Keyword(s):  
Food Waste ◽  
Structural Equation ◽  
Equation Model ◽  
The Sustainable Development ◽  
Self Reports ◽  
Negative Effect ◽  
Development Goals ◽  
Meal Planning ◽  
Food Wastage

Understanding households’ food waste drivers is crucial for forming a coherent policy to meet the sustainable development goals. However, current studies have documented mixed evidence regarding food waste determinants. Most studies have relied on self-reports, assuming they reflect actual behaviors. This study applies a structural equation model that evaluates both self-reported and measured food wastage, and how they are affected by different households’ attributes, attitudes, and behaviors. As such, it also provides a test for the underlying logic that self-reports are a proxy for actual food waste. Results show that measured food wastage is, at best, weakly correlated with self-reports. Moreover, drivers affecting self-reported and measured food wastage are not necessarily the same. Household size affects only measured food wastage. Source separation behavior negatively affects self-reported and measured food wastage, while environmental attitudes have a negative effect only on self-reports. Meal planning, unplanned shopping, and food purchased have no impact on self-reported and measured food wastage. The relation between self-reported and actual food waste and their drivers are even less understood than we thought. The distinction between self-reports and actual waste is crucial for follow-up research on this subject as well as assessing policy measures.

A longitudinal study of personality and major depression in a population-based sample of male twins

2007 ◽  
Vol 37 (8) ◽  
pp. 1163-1172 ◽  
Author(s):  
AYMAN H. FANOUS ◽  
MICHAEL C. NEALE ◽  
STEVEN H. AGGEN ◽  
KENNETH S. KENDLER
Keyword(s):  
Major Depression ◽  
Environmental Factors ◽  
Structural Equation ◽  
Causal Effect ◽  
Population Based ◽  
Twin Model ◽  
Genetic Overlap ◽  
Genetic And Environmental Factors ◽  
One Year ◽  
Time To Onset

ABSTRACTBackgroundThe relationship between personality and psychiatric illness is complex. It is not clear whether one directly causes the other.MethodIn a population-based sample of male twins (n=3030), we attempted to predict major depression (MD) from neuroticism (N) and extraversion (E) and vice versa, to evaluate the causal, scar, state, and prodromal hypotheses. In a longitudinal, structural equation twin model, we decomposed the covariation between N and MD into (a) genetic and environmental factors that are common to both traits, as well as specific to each one and (b) direct causal effects of N at time 1 on subsequent MD, as well as between MD and subsequent N.ResultsE was negatively correlated with lifetime and one-year prevalence of MD. N predicted the new onset of MD, and was predicted by both current and past MD. It did not predict the time to onset of MD. All of the covariation between N and MD was due to additive genetic and individual-specific environmental factors shared by both traits and a direct causal path between MD and N assessed later. No genetic factors were unique to either trait.ConclusionsIn men, N may be a vulnerability factor for MD but does not cause it directly. However, MD may have a direct causal effect on N. The genetic overlap between N and MD in men may be greater than in women.

Exploring Genetic and Environmental Influences on Miscarriage Rates: A Twin Study

2010 ◽  
Vol 13 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Andrea V. Burri ◽  
Lynn Cherkas ◽  
Timothy D. Spector
Keyword(s):  
Environmental Factors ◽  
Twin Study ◽  
Variance Components ◽  
Model Fitting ◽  
Genetic Influence ◽  
Shared Environment ◽  
Pair Correlations ◽  
Relative Contribution ◽  
Genetic And Environmental Factors ◽  
Common Variable

AbstractMiscarriage is the most common type of pregnancy loss, occurring in up to 15% of clinically recognized pregnancies. Our understanding of the etiology is still limited but is believed to be multifactorial, including endocrine and anatomical abnormalities, immunologic, genetic and lifestyle factors. The aim of this study was to explore whether genetic variability in miscarriage is under any genetic influence. 3234 MZ and DZ female twins completed postal self-completion questionnaires on pregnancies. Rates were adjusted for total number of pregnancies. The relative contribution of genetic and environmental factors to variation in miscarriage was assessed using twin intra-pair correlations and quantified using a variance components model fitting approach. We found 22.7% of our twins reporting having suffered at least one miscarriage. Current age, age at first pregnancy and higher number of pregnancies all had a significant influence on reported miscarriage. The concordance of miscarriage was similar in identical and non-identical twins, 26% and 27%, respectively. Shared environment and predominantly random error and unique environment rather than genetic factors best explained the total variation of miscarriage. To our knowledge, this is the first large twin study exploring heritability of miscarriage which unlike the vast majority of common variable traits, shows no significant genetic influence. In the absence of clear environmental factors, these results suggest the influence of random factors.

Level of family dysfunction and genetic influences on smoking in women

2004 ◽  
Vol 34 (7) ◽  
pp. 1263-1269 ◽  
Author(s):  
KENNETH S. KENDLER ◽  
STEVEN H. AGGEN ◽  
CAROL A. PRESCOTT ◽  
KRISTEN C. JACOBSON ◽  
MICHAEL C. NEALE
Keyword(s):  
Family Of Origin ◽  
Structural Equation ◽  
Population Based ◽  
Family Dysfunction ◽  
Equation Model ◽  
Shared Environment ◽  
Adoption Study ◽  
Twin Model ◽  
The Family ◽  
The Impact

Background. An adoption study of alcoholism suggests that in women, the impact of genetic risk factors become greater in the presence of conflict in the family of origin. Is the same true for cigarette smoking (CS)?Method. We obtained, in a sample of 1676 twins from female–female twin pairs from a population-based register, a measure of maximum lifetime CS (divided into six ordinal categories) and family dysfunction (FD) assessed as the mean report of up to four informants (twin, co-twin, mother, father). Statistical analysis was conducted by traditional regression analysis and a moderator structural equation twin model using the computer program Mx.Results. With increasing levels of FD, maximum CS increased substantially while correlations for CS in monozygotic (MZ) and dizygotic (DZ) twins decreased modestly. Regression analyses demonstrated reduced twin-pair resemblance for CS with increasing levels of FD. The best-fit structural equation model found high levels of heritability for CS and no evidence for a role of shared environment. With increasing levels of FD, the proportion of variance in CS due to genetic factors (i.e. heritability) decreased while that due to unique environmental effects increased.Conclusions. Several different statistical methods suggested that, contrary to prediction, heritability of CS decreased rather than increased with higher levels of dysfunction in the family of origin. The hypothesis that genetic effects for psychiatric and drug-use disorders become stronger in more adverse environments is not universally true.

Genetic and Cultural Transmission of Antisocial Behavior: An Extended Twin Parent Model

2007 ◽  
Vol 10 (1) ◽  
pp. 136-150 ◽  
Author(s):  
Hermine H. Maes ◽  
Judy L. Silberg ◽  
Michael C. Neale ◽  
Lindon J. Eaves
Keyword(s):  
Environmental Factors ◽  
Antisocial Behavior ◽  
Assortative Mating ◽  
Cultural Transmission ◽  
Shared Environment ◽  
Simultaneous Estimation ◽  
Adoption Studies ◽  
Expression Of Genes ◽  
Genes And Environment ◽  
Genetic And Environmental Factors

AbstractConsiderable evidence from twin and adoption studies indicates that both genetic and shared environmental factors play a substantial role in the liability to antisocial behavior. Although twin and adoption designs can resolve genetic and environmental influences, they do not provide information about assortative mating, parent–offspring transmission, or the contribution of these factors to trait variation. We examined the role of genetic and environmental factors for conduct disorder (CD) using a twin–parent design. This design allows the simultaneous estimation of additive genetic, shared and individual-specific environmental effects, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission. A retrospective measure of CD was obtained from twins and their parents or guardians in the Virginia Twin Study of Adolescent Behavior Development and its Young Adult Follow up sample. Both genetic and environmental factors play a significant role in the liability to CD. Major influences on individual differences appeared to be additive genetic (38%–40%) and unique environmental (39%–42%) effects, with smaller contributions from the shared environment (18%–23%), assortative mating (~2%), cultural transmission (~2%) and resulting genotype-environment covariance. This study showed significant heritability, which is slightly increased by assortative mating, and significant effects of primarily nonparental shared environment on CD.

scholarly journals The Model of Odonate Diversity Relationship with Environmental Factors Based on Path Analysis

el–Hayah ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 07
Author(s):  
Bambang Feriwibisono ◽  
Marsoedi Marsoedi ◽  
Amin Setyo Leksono
Keyword(s):  
Water Quality ◽  
Environmental Factors ◽  
Light Intensity ◽  
Structural Equation Model ◽  
Structural Equation ◽  
Equation Model ◽  
Water Velocity ◽  
Microsoft Excel ◽  
Vegetation Characteristics ◽  
The Relationship

This study aims to analyze and describe the relationship between altitude, aerial variables (temperature, light intensity, humidity), water qualities (water temperature, pH, BOD, COD, DO, TOM, and water velocity), and vegetation with the diversity of Odonate assemblages. Odonate samplings were conducted at six survey sites based on altitude and vegetation characteristics. Measurement of altitude, aerial variables, water qualities and vegetation characteristics were replicate in the first day and third day. Analysis of correlations of all environmental factors with the odonate diversity was done through structural equation model using Partial Least Squares (PLS), Open source Smart Software and Microsoft Excel. The aerial variables and water qualities affected indirectly on odonate diversity. The aerial variables directly or with interaction to other factor affected the water qualities and vegetation characteristics. The vegetation characteristics directly influenced to odonate diversity. Water flow affected water quality, light intensity affected the aerial, while morning period observation affected the odonate diversity. Predictive relevance (Q2) for a model designed amounted to 99.95%, while the rest of 0.05% are explained by other variables.<p> </p>

scholarly journals Competing complexity metrics and adults' production of complex sentences

1992 ◽  
Vol 13 (1) ◽  
pp. 53-76 ◽  
Author(s):  
Hintat Cheung ◽  
Susan Kemper
Keyword(s):  
Individual Differences ◽  
Structural Equation ◽  
Equation Model ◽  
Equation Modeling ◽  
Group Differences ◽  
Age Group ◽  
Complex Sentences ◽  
Complexity Metrics ◽  
Modeling Techniques

ABSTRACTThe adequacy of 11 metrics for measuring linguistic complexity was evaluated by applying each metric to language samples obtained from 30 different adult speakers, aged 60–90 years. The analysis then determined how well each metric indexed age-group differences in complexity. In addition, individual differences in the complexity of adults' language were examined as a function of these complexity metrics using structural equation modeling techniques. In a follow-up study, judges listened to sentences in noise, rated their comprehensibility, and attempted to recall each sentence verbatim. Hierarchical multiple regression was used to evaluate the structural equation model, derived from the language samples, with respect to sentence comprehensibility and recall. While most of the metrics provided an adequate account of age-group and individual differences in complexity, the amount of embedding and the type of embedding proved to predict how easily sentences are understood and how accurately they are recalled.

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